diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,675 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. By contrast, +the GNU General Public License is intended to guarantee your freedom to +share and change all versions of a program--to make sure it remains free +software for all its users. We, the Free Software Foundation, use the +GNU General Public License for most of our software; it applies also to +any other work released this way by its authors. You can apply it to +your programs, too. + + When we speak of free software, we are referring to freedom, not +price. Our General Public Licenses are designed to make sure that you +have the freedom to distribute copies of free software (and charge for +them if you wish), that you receive source code or can get it if you +want it, that you can change the software or use pieces of it in new +free programs, and that you know you can do these things. + + To protect your rights, we need to prevent others from denying you +these rights or asking you to surrender the rights. Therefore, you have +certain responsibilities if you distribute copies of the software, or if +you modify it: responsibilities to respect the freedom of others. + + For example, if you distribute copies of such a program, whether +gratis or for a fee, you must pass on to the recipients the same +freedoms that you received. You must make sure that they, too, receive +or can get the source code. And you must show them these terms so they +know their rights. + + Developers that use the GNU GPL protect your rights with two steps: +(1) assert copyright on the software, and (2) offer you this License +giving you legal permission to copy, distribute and/or modify it. + + For the developers' and authors' protection, the GPL clearly explains +that there is no warranty for this free software. For both users' and +authors' sake, the GPL requires that modified versions be marked as +changed, so that their problems will not be attributed erroneously to +authors of previous versions. + + Some devices are designed to deny users access to install or run +modified versions of the software inside them, although the manufacturer +can do so. This is fundamentally incompatible with the aim of +protecting users' freedom to change the software. The systematic +pattern of such abuse occurs in the area of products for individuals to +use, which is precisely where it is most unacceptable. Therefore, we +have designed this version of the GPL to prohibit the practice for those +products. If such problems arise substantially in other domains, we +stand ready to extend this provision to those domains in future versions +of the GPL, as needed to protect the freedom of users. + + Finally, every program is threatened constantly by software patents. +States should not allow patents to restrict development and use of +software on general-purpose computers, but in those that do, we wish to +avoid the special danger that patents applied to a free program could +make it effectively proprietary. To prevent this, the GPL assures that +patents cannot be used to render the program non-free. + + The precise terms and conditions for copying, distribution and +modification follow. + + TERMS AND CONDITIONS + + 0. Definitions. + + "This License" refers to version 3 of the GNU General Public License. + + "Copyright" also means copyright-like laws that apply to other kinds of +works, such as semiconductor masks. + + "The Program" refers to any copyrightable work licensed under this +License. Each licensee is addressed as "you". "Licensees" and +"recipients" may be individuals or organizations. + + To "modify" a work means to copy from or adapt all or part of the work +in a fashion requiring copyright permission, other than the making of an +exact copy. The resulting work is called a "modified version" of the +earlier work or a work "based on" the earlier work. + + A "covered work" means either the unmodified Program or a work based +on the Program. + + To "propagate" a work means to do anything with it that, without +permission, would make you directly or secondarily liable for +infringement under applicable copyright law, except executing it on a +computer or modifying a private copy. Propagation includes copying, +distribution (with or without modification), making available to the +public, and in some countries other activities as well. + + To "convey" a work means any kind of propagation that enables other +parties to make or receive copies. Mere interaction with a user through +a computer network, with no transfer of a copy, is not conveying. + + An interactive user interface displays "Appropriate Legal Notices" +to the extent that it includes a convenient and prominently visible +feature that (1) displays an appropriate copyright notice, and (2) +tells the user that there is no warranty for the work (except to the +extent that warranties are provided), that licensees may convey the +work under this License, and how to view a copy of this License. If +the interface presents a list of user commands or options, such as a +menu, a prominent item in the list meets this criterion. + + 1. Source Code. + + The "source code" for a work means the preferred form of the work +for making modifications to it. "Object code" means any non-source +form of a work. + + A "Standard Interface" means an interface that either is an official +standard defined by a recognized standards body, or, in the case of +interfaces specified for a particular programming language, one that +is widely used among developers working in that language. + + The "System Libraries" of an executable work include anything, other +than the work as a whole, that (a) is included in the normal form of +packaging a Major Component, but which is not part of that Major +Component, and (b) serves only to enable use of the work with that +Major Component, or to implement a Standard Interface for which an +implementation is available to the public in source code form. A +"Major Component", in this context, means a major essential component +(kernel, window system, and so on) of the specific operating system +(if any) on which the executable work runs, or a compiler used to +produce the work, or an object code interpreter used to run it. + + The "Corresponding Source" for a work in object code form means all +the source code needed to generate, install, and (for an executable +work) run the object code and to modify the work, including scripts to +control those activities. However, it does not include the work's +System Libraries, or general-purpose tools or generally available free +programs which are used unmodified in performing those activities but +which are not part of the work. For example, Corresponding Source +includes interface definition files associated with source files for +the work, and the source code for shared libraries and dynamically +linked subprograms that the work is specifically designed to require, +such as by intimate data communication or control flow between those +subprograms and other parts of the work. + + The Corresponding Source need not include anything that users +can regenerate automatically from other parts of the Corresponding +Source. + + The Corresponding Source for a work in source code form is that +same work. + + 2. Basic Permissions. + + All rights granted under this License are granted for the term of +copyright on the Program, and are irrevocable provided the stated +conditions are met. This License explicitly affirms your unlimited +permission to run the unmodified Program. The output from running a +covered work is covered by this License only if the output, given its +content, constitutes a covered work. This License acknowledges your +rights of fair use or other equivalent, as provided by copyright law. + + You may make, run and propagate covered works that you do not +convey, without conditions so long as your license otherwise remains +in force. You may convey covered works to others for the sole purpose +of having them make modifications exclusively for you, or provide you +with facilities for running those works, provided that you comply with +the terms of this License in conveying all material for which you do +not control copyright. Those thus making or running the covered works +for you must do so exclusively on your behalf, under your direction +and control, on terms that prohibit them from making any copies of +your copyrighted material outside their relationship with you. + + Conveying under any other circumstances is permitted solely under +the conditions stated below. Sublicensing is not allowed; section 10 +makes it unnecessary. + + 3. Protecting Users' Legal Rights From Anti-Circumvention Law. + + No covered work shall be deemed part of an effective technological +measure under any applicable law fulfilling obligations under article +11 of the WIPO copyright treaty adopted on 20 December 1996, or +similar laws prohibiting or restricting circumvention of such +measures. + + When you convey a covered work, you waive any legal power to forbid +circumvention of technological measures to the extent such circumvention +is effected by exercising rights under this License with respect to +the covered work, and you disclaim any intention to limit operation or +modification of the work as a means of enforcing, against the work's +users, your or third parties' legal rights to forbid circumvention of +technological measures. + + 4. Conveying Verbatim Copies. + + You may convey verbatim copies of the Program's source code as you +receive it, in any medium, provided that you conspicuously and +appropriately publish on each copy an appropriate copyright notice; +keep intact all notices stating that this License and any +non-permissive terms added in accord with section 7 apply to the code; +keep intact all notices of the absence of any warranty; and give all +recipients a copy of this License along with the Program. + + You may charge any price or no price for each copy that you convey, +and you may offer support or warranty protection for a fee. + + 5. Conveying Modified Source Versions. + + You may convey a work based on the Program, or the modifications to +produce it from the Program, in the form of source code under the +terms of section 4, provided that you also meet all of these conditions: + + a) The work must carry prominent notices stating that you modified + it, and giving a relevant date. + + b) The work must carry prominent notices stating that it is + released under this License and any conditions added under section + 7. This requirement modifies the requirement in section 4 to + "keep intact all notices". + + c) You must license the entire work, as a whole, under this + License to anyone who comes into possession of a copy. This + License will therefore apply, along with any applicable section 7 + additional terms, to the whole of the work, and all its parts, + regardless of how they are packaged. This License gives no + permission to license the work in any other way, but it does not + invalidate such permission if you have separately received it. + + d) If the work has interactive user interfaces, each must display + Appropriate Legal Notices; however, if the Program has interactive + interfaces that do not display Appropriate Legal Notices, your + work need not make them do so. + + A compilation of a covered work with other separate and independent +works, which are not by their nature extensions of the covered work, +and which are not combined with it such as to form a larger program, +in or on a volume of a storage or distribution medium, is called an +"aggregate" if the compilation and its resulting copyright are not +used to limit the access or legal rights of the compilation's users +beyond what the individual works permit. Inclusion of a covered work +in an aggregate does not cause this License to apply to the other +parts of the aggregate. + + 6. Conveying Non-Source Forms. + + You may convey a covered work in object code form under the terms +of sections 4 and 5, provided that you also convey the +machine-readable Corresponding Source under the terms of this License, +in one of these ways: + + a) Convey the object code in, or embodied in, a physical product + (including a physical distribution medium), accompanied by the + Corresponding Source fixed on a durable physical medium + customarily used for software interchange. + + b) Convey the object code in, or embodied in, a physical product + (including a physical distribution medium), accompanied by a + written offer, valid for at least three years and valid for as + long as you offer spare parts or customer support for that product + model, to give anyone who possesses the object code either (1) a + copy of the Corresponding Source for all the software in the + product that is covered by this License, on a durable physical + medium customarily used for software interchange, for a price no + more than your reasonable cost of physically performing this + conveying of source, or (2) access to copy the + Corresponding Source from a network server at no charge. + + c) Convey individual copies of the object code with a copy of the + written offer to provide the Corresponding Source. This + alternative is allowed only occasionally and noncommercially, and + only if you received the object code with such an offer, in accord + with subsection 6b. + + d) Convey the object code by offering access from a designated + place (gratis or for a charge), and offer equivalent access to the + Corresponding Source in the same way through the same place at no + further charge. You need not require recipients to copy the + Corresponding Source along with the object code. If the place to + copy the object code is a network server, the Corresponding Source + may be on a different server (operated by you or a third party) + that supports equivalent copying facilities, provided you maintain + clear directions next to the object code saying where to find the + Corresponding Source. Regardless of what server hosts the + Corresponding Source, you remain obligated to ensure that it is + available for as long as needed to satisfy these requirements. + + e) Convey the object code using peer-to-peer transmission, provided + you inform other peers where the object code and Corresponding + Source of the work are being offered to the general public at no + charge under subsection 6d. + + A separable portion of the object code, whose source code is excluded +from the Corresponding Source as a System Library, need not be +included in conveying the object code work. + + A "User Product" is either (1) a "consumer product", which means any +tangible personal property which is normally used for personal, family, +or household purposes, or (2) anything designed or sold for incorporation +into a dwelling. In determining whether a product is a consumer product, +doubtful cases shall be resolved in favor of coverage. For a particular +product received by a particular user, "normally used" refers to a +typical or common use of that class of product, regardless of the status +of the particular user or of the way in which the particular user +actually uses, or expects or is expected to use, the product. A product +is a consumer product regardless of whether the product has substantial +commercial, industrial or non-consumer uses, unless such uses represent +the only significant mode of use of the product. + + "Installation Information" for a User Product means any methods, +procedures, authorization keys, or other information required to install +and execute modified versions of a covered work in that User Product from +a modified version of its Corresponding Source. The information must +suffice to ensure that the continued functioning of the modified object +code is in no case prevented or interfered with solely because +modification has been made. + + If you convey an object code work under this section in, or with, or +specifically for use in, a User Product, and the conveying occurs as +part of a transaction in which the right of possession and use of the +User Product is transferred to the recipient in perpetuity or for a +fixed term (regardless of how the transaction is characterized), the +Corresponding Source conveyed under this section must be accompanied +by the Installation Information. But this requirement does not apply +if neither you nor any third party retains the ability to install +modified object code on the User Product (for example, the work has +been installed in ROM). + + The requirement to provide Installation Information does not include a +requirement to continue to provide support service, warranty, or updates +for a work that has been modified or installed by the recipient, or for +the User Product in which it has been modified or installed. Access to a +network may be denied when the modification itself materially and +adversely affects the operation of the network or violates the rules and +protocols for communication across the network. + + Corresponding Source conveyed, and Installation Information provided, +in accord with this section must be in a format that is publicly +documented (and with an implementation available to the public in +source code form), and must require no special password or key for +unpacking, reading or copying. + + 7. Additional Terms. + + "Additional permissions" are terms that supplement the terms of this +License by making exceptions from one or more of its conditions. +Additional permissions that are applicable to the entire Program shall +be treated as though they were included in this License, to the extent +that they are valid under applicable law. If additional permissions +apply only to part of the Program, that part may be used separately +under those permissions, but the entire Program remains governed by +this License without regard to the additional permissions. + + When you convey a copy of a covered work, you may at your option +remove any additional permissions from that copy, or from any part of +it. (Additional permissions may be written to require their own +removal in certain cases when you modify the work.) You may place +additional permissions on material, added by you to a covered work, +for which you have or can give appropriate copyright permission. + + Notwithstanding any other provision of this License, for material you +add to a covered work, you may (if authorized by the copyright holders of +that material) supplement the terms of this License with terms: + + a) Disclaiming warranty or limiting liability differently from the + terms of sections 15 and 16 of this License; or + + b) Requiring preservation of specified reasonable legal notices or + author attributions in that material or in the Appropriate Legal + Notices displayed by works containing it; or + + c) Prohibiting misrepresentation of the origin of that material, or + requiring that modified versions of such material be marked in + reasonable ways as different from the original version; or + + d) Limiting the use for publicity purposes of names of licensors or + authors of the material; or + + e) Declining to grant rights under trademark law for use of some + trade names, trademarks, or service marks; or + + f) Requiring indemnification of licensors and authors of that + material by anyone who conveys the material (or modified versions of + it) with contractual assumptions of liability to the recipient, for + any liability that these contractual assumptions directly impose on + those licensors and authors. + + All other non-permissive additional terms are considered "further +restrictions" within the meaning of section 10. If the Program as you +received it, or any part of it, contains a notice stating that it is +governed by this License along with a term that is a further +restriction, you may remove that term. If a license document contains +a further restriction but permits relicensing or conveying under this +License, you may add to a covered work material governed by the terms +of that license document, provided that the further restriction does +not survive such relicensing or conveying. + + If you add terms to a covered work in accord with this section, you +must place, in the relevant source files, a statement of the +additional terms that apply to those files, or a notice indicating +where to find the applicable terms. + + Additional terms, permissive or non-permissive, may be stated in the +form of a separately written license, or stated as exceptions; +the above requirements apply either way. + + 8. Termination. + + You may not propagate or modify a covered work except as expressly +provided under this License. Any attempt otherwise to propagate or +modify it is void, and will automatically terminate your rights under +this License (including any patent licenses granted under the third +paragraph of section 11). + + However, if you cease all violation of this License, then your +license from a particular copyright holder is reinstated (a) +provisionally, unless and until the copyright holder explicitly and +finally terminates your license, and (b) permanently, if the copyright +holder fails to notify you of the violation by some reasonable means +prior to 60 days after the cessation. + + Moreover, your license from a particular copyright holder is +reinstated permanently if the copyright holder notifies you of the +violation by some reasonable means, this is the first time you have +received notice of violation of this License (for any work) from that +copyright holder, and you cure the violation prior to 30 days after +your receipt of the notice. + + Termination of your rights under this section does not terminate the +licenses of parties who have received copies or rights from you under +this License. If your rights have been terminated and not permanently +reinstated, you do not qualify to receive new licenses for the same +material under section 10. + + 9. Acceptance Not Required for Having Copies. + + You are not required to accept this License in order to receive or +run a copy of the Program. Ancillary propagation of a covered work +occurring solely as a consequence of using peer-to-peer transmission +to receive a copy likewise does not require acceptance. However, +nothing other than this License grants you permission to propagate or +modify any covered work. These actions infringe copyright if you do +not accept this License. Therefore, by modifying or propagating a +covered work, you indicate your acceptance of this License to do so. + + 10. Automatic Licensing of Downstream Recipients. + + Each time you convey a covered work, the recipient automatically +receives a license from the original licensors, to run, modify and +propagate that work, subject to this License. You are not responsible +for enforcing compliance by third parties with this License. + + An "entity transaction" is a transaction transferring control of an +organization, or substantially all assets of one, or subdividing an +organization, or merging organizations. If propagation of a covered +work results from an entity transaction, each party to that +transaction who receives a copy of the work also receives whatever +licenses to the work the party's predecessor in interest had or could +give under the previous paragraph, plus a right to possession of the +Corresponding Source of the work from the predecessor in interest, if +the predecessor has it or can get it with reasonable efforts. + + You may not impose any further restrictions on the exercise of the +rights granted or affirmed under this License. For example, you may +not impose a license fee, royalty, or other charge for exercise of +rights granted under this License, and you may not initiate litigation +(including a cross-claim or counterclaim in a lawsuit) alleging that +any patent claim is infringed by making, using, selling, offering for +sale, or importing the Program or any portion of it. + + 11. Patents. + + A "contributor" is a copyright holder who authorizes use under this +License of the Program or a work on which the Program is based. The +work thus licensed is called the contributor's "contributor version". + + A contributor's "essential patent claims" are all patent claims +owned or controlled by the contributor, whether already acquired or +hereafter acquired, that would be infringed by some manner, permitted +by this License, of making, using, or selling its contributor version, +but do not include claims that would be infringed only as a +consequence of further modification of the contributor version. For +purposes of this definition, "control" includes the right to grant +patent sublicenses in a manner consistent with the requirements of +this License. + + Each contributor grants you a non-exclusive, worldwide, royalty-free +patent license under the contributor's essential patent claims, to +make, use, sell, offer for sale, import and otherwise run, modify and +propagate the contents of its contributor version. + + In the following three paragraphs, a "patent license" is any express +agreement or commitment, however denominated, not to enforce a patent +(such as an express permission to practice a patent or covenant not to +sue for patent infringement). To "grant" such a patent license to a +party means to make such an agreement or commitment not to enforce a +patent against the party. + + If you convey a covered work, knowingly relying on a patent license, +and the Corresponding Source of the work is not available for anyone +to copy, free of charge and under the terms of this License, through a +publicly available network server or other readily accessible means, +then you must either (1) cause the Corresponding Source to be so +available, or (2) arrange to deprive yourself of the benefit of the +patent license for this particular work, or (3) arrange, in a manner +consistent with the requirements of this License, to extend the patent +license to downstream recipients. "Knowingly relying" means you have +actual knowledge that, but for the patent license, your conveying the +covered work in a country, or your recipient's use of the covered work +in a country, would infringe one or more identifiable patents in that +country that you have reason to believe are valid. + + If, pursuant to or in connection with a single transaction or +arrangement, you convey, or propagate by procuring conveyance of, a +covered work, and grant a patent license to some of the parties +receiving the covered work authorizing them to use, propagate, modify +or convey a specific copy of the covered work, then the patent license +you grant is automatically extended to all recipients of the covered +work and works based on it. + + A patent license is "discriminatory" if it does not include within +the scope of its coverage, prohibits the exercise of, or is +conditioned on the non-exercise of one or more of the rights that are +specifically granted under this License. You may not convey a covered +work if you are a party to an arrangement with a third party that is +in the business of distributing software, under which you make payment +to the third party based on the extent of your activity of conveying +the work, and under which the third party grants, to any of the +parties who would receive the covered work from you, a discriminatory +patent license (a) in connection with copies of the covered work +conveyed by you (or copies made from those copies), or (b) primarily +for and in connection with specific products or compilations that +contain the covered work, unless you entered into that arrangement, +or that patent license was granted, prior to 28 March 2007. + + Nothing in this License shall be construed as excluding or limiting +any implied license or other defenses to infringement that may +otherwise be available to you under applicable patent law. + + 12. No Surrender of Others' Freedom. + + If conditions are imposed on you (whether by court order, agreement or +otherwise) that contradict the conditions of this License, they do not +excuse you from the conditions of this License. If you cannot convey a +covered work so as to satisfy simultaneously your obligations under this +License and any other pertinent obligations, then as a consequence you may +not convey it at all. For example, if you agree to terms that obligate you +to collect a royalty for further conveying from those to whom you convey +the Program, the only way you could satisfy both those terms and this +License would be to refrain entirely from conveying the Program. + + 13. Use with the GNU Affero General Public License. + + Notwithstanding any other provision of this License, you have +permission to link or combine any covered work with a work licensed +under version 3 of the GNU Affero General Public License into a single +combined work, and to convey the resulting work. The terms of this +License will continue to apply to the part which is the covered work, +but the special requirements of the GNU Affero General Public License, +section 13, concerning interaction through a network will apply to the +combination as such. + + 14. Revised Versions of this License. + + The Free Software Foundation may publish revised and/or new versions of +the GNU General Public License from time to time. Such new versions will +be similar in spirit to the present version, but may differ in detail to +address new problems or concerns. + + Each version is given a distinguishing version number. If the +Program specifies that a certain numbered version of the GNU General +Public License "or any later version" applies to it, you have the +option of following the terms and conditions either of that numbered +version or of any later version published by the Free Software +Foundation. If the Program does not specify a version number of the +GNU General Public License, you may choose any version ever published +by the Free Software Foundation. + + If the Program specifies that a proxy can decide which future +versions of the GNU General Public License can be used, that proxy's +public statement of acceptance of a version permanently authorizes you +to choose that version for the Program. + + Later license versions may give you additional or different +permissions. However, no additional obligations are imposed on any +author or copyright holder as a result of your choosing to follow a +later version. + + 15. Disclaimer of Warranty. + + THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY +APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT +HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY +OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, +THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM +IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF +ALL NECESSARY SERVICING, REPAIR OR CORRECTION. + + 16. Limitation of Liability. + + IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING +WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS +THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY +GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE +USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF +DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD +PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), +EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF +SUCH DAMAGES. + + 17. Interpretation of Sections 15 and 16. + + If the disclaimer of warranty and limitation of liability provided +above cannot be given local legal effect according to their terms, +reviewing courts shall apply local law that most closely approximates +an absolute waiver of all civil liability in connection with the +Program, unless a warranty or assumption of liability accompanies a +copy of the Program in return for a fee. + + END OF TERMS AND CONDITIONS + + How to Apply These Terms to Your New Programs + + If you develop a new program, and you want it to be of the greatest +possible use to the public, the best way to achieve this is to make it +free software which everyone can redistribute and change under these terms. + + To do so, attach the following notices to the program. It is safest +to attach them to the start of each source file to most effectively +state the exclusion of warranty; and each file should have at least +the "copyright" line and a pointer to where the full notice is found. + + + Copyright (C) + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . + +Also add information on how to contact you by electronic and paper mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + Copyright (C) + This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, your program's commands +might be different; for a GUI interface, you would use an "about box". + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU GPL, see +. + + The GNU General Public License does not permit incorporating your program +into proprietary programs. If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. + diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,5 @@ +#!/usr/bin/env runhaskell + +import qualified Distribution.Simple + +main = Distribution.Simple.defaultMain diff --git a/changelog b/changelog new file mode 100644 --- /dev/null +++ b/changelog @@ -0,0 +1,25 @@ +2010-11-18 Dr. Alistair Ward + +0.9.0.0 + * First version of the package. +0.10.0.0 + * Reacted to major-number changes in the package 'ToolShed-0.10.0.0'. + * Created "src/RegExDot/" sub-directory & then modified module-names accordingly. + * Pacified 'hlint'. + * Added a makefile. + * Removed awkward unary operators from 'Repeatable.hs'. + * Qualified identifiers used in error-messages. +0.10.0.1 + * Ported to ghc-7.0.1: + Used definitions of 'NFData' & 'rnf' from new package 'deepseq', rather than 'parallel'. + Replaced reference to the deprecated function 'Control.Parallel.Strategies.parFlatMap' with @concat . Control.Parallel.Strategies.parMap@. +0.10.1.0 + * Set @threaded@ flag to @True@ by default. + * Replaced use of @threaded@-flag in source-code, with CABAL CPP-macro. + * Relocated "RegExDot.Options" to "ToolShed.Options". +0.10.2.0 + * Renamed package from 'RegExDot' to 'regexdot', for compatibility with Debian's ".deb"-format. +0.10.2.1 + * Added manually controlled "llvm" flag to "regexdot.cabal". + * Changed identifier for type-parameters, to better reflect its role. + * Reacted to the creation of module "ToolShed.Defaultable". diff --git a/copyright b/copyright new file mode 100644 --- /dev/null +++ b/copyright @@ -0,0 +1,11 @@ +Author: + Dr. Alistair Ward . + +Copyright: + Copyright (C) 2010-2011 Dr. Alistair Ward. All Rights Reserved. + +Home-page: + http://functionalley.eu + +License: + GNU GENERAL PUBLIC LICENSE Version 3; see '/usr/share/common-licenses/GPL-3' or '/usr/share/doc/licenses/gpl-3.0.txt' where available, or the local packaged file 'LICENSE'. diff --git a/makefile b/makefile new file mode 100644 --- /dev/null +++ b/makefile @@ -0,0 +1,55 @@ +# Copyright (C) 2010 Dr. Alistair Ward +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +.PHONY: all build clean configure copy haddock help hlint install prof sdist + +all: install + +install: build haddock + @[ -z "$$CABAL_INSTALL_OPTIONS" ] || echo "INFO: CABAL_INSTALL_OPTIONS='$$CABAL_INSTALL_OPTIONS'" + runhaskell Setup.hs $@ $$CABAL_INSTALL_OPTIONS + +prof: + CABAL_CONFIGURE_OPTIONS="--enable-library-profiling $$CABAL_CONFIGURE_OPTIONS" make install + +copy: build + @[ -z "$$CABAL_COPY_OPTIONS" ] || echo "INFO: CABAL_COPY_OPTIONS='$$CABAL_COPY_OPTIONS'" + runhaskell Setup.hs $@ $$CABAL_COPY_OPTIONS + +build: configure + @[ -z "$$CABAL_BUILD_OPTIONS" ] || echo "INFO: CABAL_BUILD_OPTIONS='$$CABAL_BUILD_OPTIONS'" + runhaskell Setup.hs $@ $$CABAL_BUILD_OPTIONS + +configure: regexdot.cabal Setup.hs + @[ -z "$$CABAL_CONFIGURE_OPTIONS" ] || echo "INFO: CABAL_CONFIGURE_OPTIONS='$$CABAL_CONFIGURE_OPTIONS'" + runhaskell Setup.hs $@ $$CABAL_CONFIGURE_OPTIONS #--user + +haddock: configure + PATH=~/.cabal/bin:$$PATH runhaskell Setup.hs $@ --hyperlink-source #Amend path to find 'HsColour', as required for 'hyperlink-source'. + +hlint: + @$@ src/ + +sdist: configure + runhaskell Setup.hs $@ + +clean: + runhaskell Setup.hs $@ + +help: + @grep '^[a-zA-Z].*:' makefile | sed -e 's/:.*//' + +rpm: regexdot.rpm build + diff --git a/regexdot.cabal b/regexdot.cabal new file mode 100644 --- /dev/null +++ b/regexdot.cabal @@ -0,0 +1,80 @@ +--Package-properties +Name: regexdot +Version: 0.10.2.1 +Cabal-Version: >= 1.6 +Copyright: (C) 2010 Dr. Alistair Ward +License: GPL +License-file: LICENSE +Author: Dr. Alistair Ward +Stability: Unstable interface, incomplete features. +Synopsis: A /polymorphic/, POSIX, extended regular-expression engine. +Build-Type: Simple +Description: Provides a portable, POSIX, extended regex-engine, designed to process a list of /arbitrary/ objects. +Category: Search, Regex +Tested-With: GHC == 6.10, GHC == 6.12, GHC == 7.0 +Homepage: http://functionalley.eu +Maintainer: regexdot functionalley eu +Bug-reports: regexdot functionalley eu +Extra-Source-Files: changelog, copyright, makefile + +flag haveDeepSeq + Description: Use 'Control.DeepSeq' rather than the older module 'Control.Parallel.Strategies'. + Default: True + +flag llvm + Description: Whether the 'llvm' backend has been installed and is required for code-generation. + manual: True + default: False + +flag threaded + Description: Enable parallelized code. + default: True + +Library + hs-source-dirs: src + + Exposed-modules: + RegExDot.Anchor + RegExDot.BracketExpression + RegExDot.BracketExpressionMember + RegExDot.CompilationOptions + RegExDot.Consumer + RegExDot.ConsumptionBounds + RegExDot.ConsumptionProfile + RegExDot.DataSpan + RegExDot.DataSpanTree + RegExDot.DSL + RegExDot.ExecutionOptions + RegExDot.InstanceInt + RegExDot.Meta + RegExDot.RegEx + RegExDot.RegExOpts + RegExDot.Repeatable + RegExDot.Result + RegExDot.ShowablePredicate + RegExDot.Span + RegExDot.Tree + + Build-depends: + base == 4.*, + parsec == 3.*, + toolshed == 0.11.* + + GHC-options: -Wall -O2 + GHC-prof-options: -prof -auto-all -caf-all + + if flag(haveDeepSeq) + Build-depends: deepseq >= 1.1 + CPP-options: -DHAVE_DEEPSEQ + else + Build-depends: parallel == 1.* + + if flag(threaded) + Build-depends: parallel >= 3.0 + GHC-options: -feager-blackholing + else + Build-depends: parallel + + if impl(ghc >= 7.0) && flag(llvm) + GHC-options: -fllvm + diff --git a/src/RegExDot/Anchor.hs b/src/RegExDot/Anchor.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/Anchor.hs @@ -0,0 +1,85 @@ +{-# LANGUAGE CPP #-} +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] + + * A type of /zero-width assertion/: + the 'Bow'-predicate is 'True' if no input-data has yet been consumed; the 'Stern'-predicate is 'True' if no input-data remains to be consumed. + + * Whilst at the top-level of the regex, the /absence/ of an anchor is equivalent to a non-capturing @.*?@, + tempting one to implement them using this property, + it doesn't apply to those anchors encountered at either end of a sub-expression. + So in all cases, an anchor constrains the permissible consumption of input-data, + but at the top level it also prevents the regex drifting away from either end of the input-data. +-} + +module RegExDot.Anchor( +-- * Types +-- ** Data-types + Anchor(..), +-- * Constants + bowToken, + sternToken, + tokens +) where + +#ifdef HAVE_DEEPSEQ +import Control.DeepSeq(NFData, rnf) +#else +import Control.Parallel.Strategies(NFData, rnf) +#endif + +-- | Defines the types on /anchor/ by which a /regex/ can be moored to a part of the input-data. +data Anchor = + Bow -- ^ Matches only if no input data has yet been consumed. Can only exist at the start of the entire regex, or (in theory) the start of any /alternative/. + | Stern -- ^ Matches only if no input data remains to be consumed. Can only exist at the end of the entire regex, or (in theory) the end of any /alternative/. + deriving ( + Eq +-- Read, --See specialisation below. +-- Show --See specialisation below. + ) + +instance Show Anchor where + showsPrec _ Bow = showChar bowToken + showsPrec _ Stern = showChar sternToken + +instance Read Anchor where + readsPrec _ [] = [] --No parse. + readsPrec _ (' ' : s) = reads s --Consume white-space. + readsPrec _ ('\t' : s) = reads s --Consume white-space. + readsPrec _ (c : s) = case c `lookup` [(bowToken, Bow), (sternToken, Stern)] of + Just anchor -> [(anchor, s)] + _ -> [] --No parse. + +instance NFData Anchor where + rnf _ = () + +-- | The conventional token used to denote a 'Bow'-anchor, when in 'String'-form. +bowToken :: Char +bowToken = '^' + +-- | The conventional token used to denote a 'Stern'-anchor, when in 'String'-form. +sternToken :: Char +sternToken = '$' + +-- | The set of 'Char' to which a specific meaning is attributed, when reading from 'String'. +tokens :: String +tokens = [bowToken, sternToken] + diff --git a/src/RegExDot/BracketExpression.hs b/src/RegExDot/BracketExpression.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/BracketExpression.hs @@ -0,0 +1,63 @@ +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] + + This concept was traditionally known as a /Character-class/, + but to distinguish it from the more recently introduced & narrower /POSIX Character-class/, it has been renamed /Bracket-expression/. +-} + +module RegExDot.BracketExpression( +-- * Types +-- ** Type-synonyms + BracketExpression, +-- * Constants + delimiterTokens, + negationToken, + tokens, +-- * Functions +-- ** Predicates + containsMatch +) where + +import RegExDot.BracketExpressionMember((=~)) +import qualified RegExDot.BracketExpressionMember as BracketExpressionMember + +-- | A /Bracket-expression/ consists of a list of 'BracketExpressionMember.Member's. +type BracketExpression m = [BracketExpressionMember.Member m] + +-- | 'True' if the specified datum matches any 'BracketExpressionMember.Member' of the 'BracketExpression'. +containsMatch :: Eq m + => m -- ^ The input datum. + -> BracketExpression m -- ^ The list of bracket-expression members within which to find a match. + -> Bool +containsMatch datum = any (datum =~) + +-- | The delimiters of a /bracket-expression/, when in 'String'-form. +delimiterTokens :: (Char, Char) +delimiterTokens = ('[', ']') + +-- | Used to denote a negated /bracket-expression/, when in 'String'-form. +negationToken :: Char +negationToken = '^' + +-- | The set of 'Char' to which a specific meaning is attributed, when reading from 'String'. +tokens :: String +tokens = [fst delimiterTokens, snd delimiterTokens, negationToken] + diff --git a/src/RegExDot/BracketExpressionMember.hs b/src/RegExDot/BracketExpressionMember.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/BracketExpressionMember.hs @@ -0,0 +1,99 @@ +{-# LANGUAGE CPP #-} +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] + + Permits /Perl-style shortcut/s to be canned & assigned a single-'Char' mnemonic for subsequent reference; + the implementation of 'Read' looks for a back-slashed 'Char', for which it expects there to be a corresponding canned 'ShowablePredicate.ShowablePredicate'. + + [@CAVEATS@] + + Since the underlying polymorphic data-type isn't required to implement neither 'Enum' nor 'Ord', the implementation of 'Read' can't cope with range-specifications. + Lacking this, Bracket-expression members must be enumerated exhaustively. +-} + +module RegExDot.BracketExpressionMember( +-- * Type-classes + ShortcutExpander(..), +-- * Types +-- ** Data-types + Member(..), +-- * Functions +-- ** Operators + (=~) +) where + +import qualified Control.Arrow +import qualified RegExDot.ShowablePredicate as ShowablePredicate + +#ifdef HAVE_DEEPSEQ +import Control.DeepSeq(NFData, rnf) +#else +import Control.Parallel.Strategies(NFData, rnf) +#endif + +infix 4 =~ --Same as (==). + +{- | + * The interface via which /Perl-style shortcut/s are expanded (when they occur within a /bracket-expression/), in a manner appropriate to the chosen type-parameter. + + * The expansion of /Perl-style shortcut/s, is more restricted inside than outside, a /bracket-expression/, + & consequently are merely represented here by a 'ShowablePredicate.ShowablePredicate', rather than providing a more general form suitable also for those /Perl-style shortcuts/ found outside /bracket-expression/s. + + * This interface is implemented elsewhere, where the specific type-parameter & consequently the appropriate set of /Perl-style shortcut/s, are defined. +-} +class ShortcutExpander a where + findPredicate :: Char -> Maybe (ShowablePredicate.ShowablePredicate a) -- ^ Attempt to find the appropriate 'ShowablePredicate.ShowablePredicate' to implement this /Perl-style shortcut/. + +{- | + * A /BracketExpression/ can contain either a literal, a range of literals given @(Enum a, Ord a)@, a /Perl-style shortcut/, or when 'Char' is the type-parameter, a /POSIX Character-class/. + + * This data-type reduces the representation of all these possibilities to either a predicate or a literal. +-} +data Member m = + Predicate (ShowablePredicate.ShowablePredicate m) -- ^ This 'Member' is described using a /predicate/, which is run to determine whether the datum conforms & is a member of the "BracketExpression". + | Literal m -- ^ This 'Member' is defined literally, using an item of the polymorphic type. + deriving Eq + +instance Show m => Show (Member m) where + showsPrec _ (Predicate showablePredicate) = shows showablePredicate + showsPrec _ (Literal literal) = shows literal + +instance (ShortcutExpander m, Read m) => Read (Member m) where + readsPrec _ [] = [] --No parse. + readsPrec _ (' ' : s) = reads s --Consume white-space. + readsPrec _ ('\t' : s) = reads s --Consume white-space. + readsPrec _ ('\\' : shortcut : s) = case findPredicate shortcut of + Just showablePredicate -> [(Predicate showablePredicate, s)] + _ -> error $ "readsPrec RegExDot.BracketExpressionMember.Member:\tfindPredicate failed for shortcut " ++ show shortcut + readsPrec _ literal = Control.Arrow.first Literal `map` reads literal + +instance NFData m => NFData (Member m) where + rnf (Predicate showablePredicate) = rnf showablePredicate + rnf (Literal literal) = rnf literal + +-- | Match-operator. +(=~) :: Eq m + => m -- ^ The input datum. + -> Member m -- ^ The member of the bracket-expression against which the input-datum is to be matched. + -> Bool -- ^ The result of the match-operation. +datum =~ Predicate showablePredicate = ShowablePredicate.predicate showablePredicate datum +datum =~ Literal literal = datum == literal + diff --git a/src/RegExDot/CompilationOptions.hs b/src/RegExDot/CompilationOptions.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/CompilationOptions.hs @@ -0,0 +1,48 @@ +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] + + * Defines those options relating to compile-time. + + * These tend to be options which affect the result, rather than the means by which it is achieved. + + * Whilst similar structures are present in other regex-implementations, there's no standardisation of the fields. +-} + +module RegExDot.CompilationOptions( +-- * Types +-- ** Data-types + CompilationOptions(..) +) where + +import qualified ToolShed.Defaultable as Defaultable +import qualified ToolShed.Options as Options + +-- | The switch(es) used to control compilation of the /regex/-engine. +data CompilationOptions = MkCompilationOptions { + complyStrictlyWithPosix :: Bool -- ^ Define the offset of captured data, corresponding to a sub-expression which matched zero times, as the artificial value @-1@ specified by POSIX. +} deriving (Eq, Show) + +instance Defaultable.Defaultable CompilationOptions where + defaultValue = Options.blankValue { complyStrictlyWithPosix = True } + +instance Options.Options CompilationOptions where + blankValue = MkCompilationOptions { complyStrictlyWithPosix = undefined } + diff --git a/src/RegExDot/Consumer.hs b/src/RegExDot/Consumer.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/Consumer.hs @@ -0,0 +1,105 @@ +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] + + * Define the requirements & capabilities of a data-type which is designed to consume data. + + * This module also facilitates investigation of group-behaviour, by defining operations on either concatenations or alternations of 'Consumer's. + + * This module is specifically for use in a /regex/-engine, + in which the meta-data from which the /regex/ is composed, are considered to /consume/ input data, + whilst concatenation & alternation of such elements, behave as a different types of groups of consumer. +-} + +module RegExDot.Consumer( +-- * Type-classes + Consumer(..), +-- * Types +-- ** Type-synonyms +-- StarHeight, +-- * Functions + accumulateConsumptionProfiles, +-- accumulateConsumptionProfilesFrom, + aggregateConsumptionProfilesFromAlternatives, + aggregateConsumptionProfilesFromConcatenation, +-- ** Query + getConsumptionBounds, + getFewest, + getHasSpecificRequirement +) where + +import RegExDot.ConsumptionProfile((<>), (|+|)) +import qualified Data.List +import qualified RegExDot.ConsumptionBounds as ConsumptionBounds +import qualified RegExDot.ConsumptionProfile as ConsumptionProfile + +{- | + * A measure of the complexity of a /regex/, which has some baring on either the time-complexity or the space-complexity of the solution. + + * +-} +type StarHeight = Int + +{- | + * The interface, to which types, which have a data-requirement, may conform. + + * Regrettably, methods requiring reference to the type of the consumable, would require multi-parameter type-classes. + + * 'consumptionProfile' defines the quantity-range of data which may be consumed, & any specific data-requirements. + + * 'starHeight' measures the complexity of the 'Consumer'. +-} +class Consumer c where + consumptionProfile :: c -> ConsumptionProfile.ConsumptionProfile + starHeight :: c -> StarHeight + +instance Consumer c => Consumer [c] where + consumptionProfile = undefined + starHeight = Data.List.foldl' (\l -> max l . starHeight) 0 + +-- | Convenience-function, to query the 'ConsumptionBounds.ConsumptionBounds' of a 'Consumer'. +getConsumptionBounds :: Consumer c => c -> ConsumptionBounds.ConsumptionBounds +getConsumptionBounds = ConsumptionProfile.consumptionBounds . consumptionProfile + +-- | Determine the minimum acceptable quantity of data. +getFewest :: Consumer c => c -> ConsumptionBounds.DataLength +getFewest = fst . getConsumptionBounds + +-- | Determine whether the specified 'Consumer', has a specific requirement. +getHasSpecificRequirement :: Consumer c => c -> Bool +getHasSpecificRequirement = ConsumptionProfile.hasSpecificRequirement . consumptionProfile + +-- | The aggregate of the specified alternation of 'ConsumptionProfile.ConsumptionProfile's. +aggregateConsumptionProfilesFromAlternatives :: Consumer c => [c] -> ConsumptionProfile.ConsumptionProfile +aggregateConsumptionProfilesFromAlternatives [] = error "RegExDot.Consumer.aggregateConsumptionProfilesFromAlternatives:\tnull list" +aggregateConsumptionProfilesFromAlternatives l = Data.List.foldl1' (<>) $ consumptionProfile `map` l + +-- | Get the 'ConsumptionProfile.ConsumptionProfile's for the specified list of 'Consumer's, then find the net effect of concatenating them. +aggregateConsumptionProfilesFromConcatenation :: Consumer c => [c] -> ConsumptionProfile.ConsumptionProfile +aggregateConsumptionProfilesFromConcatenation = Data.List.foldl' (\acc -> (acc |+|) . consumptionProfile) ConsumptionProfile.zero {-initial value-} + +-- | Get the 'ConsumptionProfile.ConsumptionProfile' for the specified list of 'Consumer's, then accumulate them, from the specified initial value. +accumulateConsumptionProfilesFrom :: Consumer c => ConsumptionProfile.ConsumptionProfile -> [c] -> ConsumptionProfile.AccumulatedConsumptionProfiles +accumulateConsumptionProfilesFrom = scanr ((|+|) . consumptionProfile) + +-- | Get the 'ConsumptionProfile.ConsumptionProfile' for the specified list of 'Consumer's, then accumulate them. +accumulateConsumptionProfiles :: Consumer c => [c] -> ConsumptionProfile.AccumulatedConsumptionProfiles +accumulateConsumptionProfiles = {-init .-} accumulateConsumptionProfilesFrom ConsumptionProfile.zero --It's useful to leave the initial value at the end of the list. + diff --git a/src/RegExDot/ConsumptionBounds.hs b/src/RegExDot/ConsumptionBounds.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/ConsumptionBounds.hs @@ -0,0 +1,48 @@ +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] Describes the bounds of data-consumption. +-} + +module RegExDot.ConsumptionBounds( +-- * Types +-- ** Type-synonyms + ConsumptionBounds, + DataLength, +-- * Constants + zero, +-- * Functions +-- ** Predicates + isPrecise +) where + +-- | A measure of the quantity of an unspecified type of data. +type DataLength = Int + +-- | The minimum & maximum bounds of potential data-consumption. +type ConsumptionBounds = (DataLength, Maybe DataLength) + +-- | Exactly zero consumption. +zero :: ConsumptionBounds +zero = (0, Just 0) + +-- | Predicate which is 'True' if only a precise quantity of data is consumable; no more, no less. +isPrecise :: ConsumptionBounds -> Bool +isPrecise (fewest, most) = Just fewest == most + diff --git a/src/RegExDot/ConsumptionProfile.hs b/src/RegExDot/ConsumptionProfile.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/ConsumptionProfile.hs @@ -0,0 +1,146 @@ +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] + + A 'RegExDot.ConsumptionProfile' is composed from both a capacity to consume, & an ability to discriminate based on the specific data. + The former is described by 'consumptionBounds' & the latter by both 'hasSpecificRequirement' & 'canConsumeAnything'. +-} + +module RegExDot.ConsumptionProfile( +-- * Types +-- ** Type-synonyms + AccumulatedConsumptionProfiles, +-- ** Data-types + ConsumptionProfile(..), +-- * Constants + zero, +-- * Functions + accumulateFrom, + aggregateFromConcatenation, +-- ** Operators + (|+|), + (<>), +-- ** Predicates +-- isPrecise, + withinConsumptionBounds +) where + +import Control.Applicative((<$>), (<*>)) +import qualified Data.List +import qualified RegExDot.ConsumptionBounds as ConsumptionBounds +import qualified ToolShed.SelfValidate as SelfValidate + +infixr 5 |+| --Same as (++). +infixr 2 <> --Same as (||). + +{- | + * A 'Consumer' is considered to have a 'ConsumptionProfile' composed from both a capacity to consume, & an ability to discriminate. + + * Whilst 'hasSpecificRequirement' & 'canConsumeAnything' look like opposites, they can assume independent values; the instance can be both, but only be neither when empty. +-} +data ConsumptionProfile = MkConsumptionProfile { + consumptionBounds :: ConsumptionBounds.ConsumptionBounds, -- ^ The permissible quantity of data, which can be consumed. + hasSpecificRequirement :: Bool, -- ^ Whether at least one specific input datum is required. + canConsumeAnything :: Bool -- ^ Whether at least one arbitrary input datum can be consumed. +} deriving (Eq, Read, Show) + +instance SelfValidate.SelfValidator ConsumptionProfile where + isValid c@( + MkConsumptionProfile { + consumptionBounds = (fewest, most), + hasSpecificRequirement = hasSpecificRequirement', + canConsumeAnything = canConsumeAnything' + } + ) = and [ + fewest >= 0, + case most of + Nothing -> True + Just m -> m >= fewest, + or [c == zero, hasSpecificRequirement', canConsumeAnything'] + ] + +{- +-- | 'True' if there's no choice in the quantity of data to consume. +isPrecise :: ConsumptionProfile -> Bool +isPrecise = ConsumptionBounds.isPrecise . consumptionBounds +-} + +-- | Predicate, which is 'True' if the specified data-length, falls within the specified 'ConsumptionBounds.ConsumptionBounds'. +withinConsumptionBounds :: + ConsumptionBounds.DataLength -- ^ The actual quantity of data consumed. + -> ConsumptionProfile -- ^ The bounds within which data-consumption is required to fall. + -> Bool +withinConsumptionBounds dataLength MkConsumptionProfile { + consumptionBounds = (minConsumption, maxConsumption) +} = dataLength >= minConsumption && case maxConsumption of + Nothing -> True + Just m -> dataLength <= m + +-- | Both minimum & maximum set to zero; which can be used as the initial value when accumulating the sum of a list. +zero :: ConsumptionProfile +zero = MkConsumptionProfile { + consumptionBounds = ConsumptionBounds.zero, + hasSpecificRequirement = False, + canConsumeAnything = False +} + +-- | The net effect of two concatenated 'ConsumptionProfile's. +(|+|) :: ConsumptionProfile -> ConsumptionProfile -> ConsumptionProfile +MkConsumptionProfile { + consumptionBounds = (lf, ls), + hasSpecificRequirement = lh, + canConsumeAnything = lc +} |+| MkConsumptionProfile { + consumptionBounds = (rf, rs), + hasSpecificRequirement = rh, + canConsumeAnything = rc +} = MkConsumptionProfile { + consumptionBounds = (lf + rf, (+) <$> ls <*> rs), --The sum of those of the concatenation. + hasSpecificRequirement = lh || rh, --The concatenation mandates consumption of at least one specific input datum, if either 'ConsumptionProfile' does. + canConsumeAnything = lc || rc --The concatenation can consume at least one arbitrary input datum, if either 'ConsumptionProfile' can. +} + +-- | The net effect of two alternative 'ConsumptionProfile's. +(<>) :: ConsumptionProfile -> ConsumptionProfile -> ConsumptionProfile +MkConsumptionProfile { + consumptionBounds = (lf, ls), + hasSpecificRequirement = lh, + canConsumeAnything = lc +} <> MkConsumptionProfile { + consumptionBounds = (rf, rs), + hasSpecificRequirement = rh, + canConsumeAnything = rc +} = MkConsumptionProfile { + consumptionBounds = (lf `min` rf, max <$> ls <*> rs), --Stretched to envelope alternatives. + hasSpecificRequirement = lh && rh, --The alternation mandates consumption of at least one specific input datum, if both 'ConsumptionProfile's do. + canConsumeAnything = lc || rc --The alternation can consume at least one arbitrary input datum, if either 'ConsumptionProfile' can. +} + +-- | The aggregate of the specified concatenation of 'ConsumptionProfile's. +aggregateFromConcatenation :: [ConsumptionProfile] -> ConsumptionProfile +aggregateFromConcatenation = Data.List.foldl' (|+|) zero {-initial value-} + +-- | The 'ConsumptionProfile's of all the aggregated tails of a list of 'Consumer's. +type AccumulatedConsumptionProfiles = [ConsumptionProfile] + +-- | Accumulate the specified list of 'ConsumptionProfile's, from the specified initial value. +accumulateFrom :: ConsumptionProfile -> [ConsumptionProfile] -> AccumulatedConsumptionProfiles +accumulateFrom = scanr (|+|) + diff --git a/src/RegExDot/DSL.hs b/src/RegExDot/DSL.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/DSL.hs @@ -0,0 +1,117 @@ +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] + + * Defines /binary/ operators, to form a /Domain-specific Language/, by which to compose 'RegEx.Concatenations' from 'RegEx.Pattern's. + + * Each operator quantifies the specified 'RegEx.Pattern', & prepends it to the specified 'RegEx.Concatenation'. + + [@TODO@] Could @[]@ & 'Meta' be instances of a type-class which has methods (-:) etc., + allowing the former to prepend 'RegEx.captureGroup' & the latter 'RegEx.Require' ? + +-} + +module RegExDot.DSL( +-- * Functions +-- ** Operators + (-:), + (?:), + (??:), + (*:), + (*?:), + (+:), + (+?:), + ( #->#:), + ( #->#?:), + ( #->:), + ( #->?:), + ( #:), + (<~>) +) where + +import RegExDot.Repeatable((^#->#), (^#->#?), (^#->), (^#->?), (^#)) +import qualified RegExDot.Anchor as Anchor +import qualified RegExDot.RegEx as RegEx +import qualified RegExDot.Repeatable as Repeatable + +infixr 5 -:, ?:, ??:, *:, *?:, +:, +?:,#->#:, #->#?:, #->:, #->?:, #:, <~> --Same as for ':', & lower than Repeatable's operators. + +-- | Prepend an unrepeated 'RegEx.Pattern', to the specified 'RegEx.Concatenation'. +(-:) :: RegEx.Pattern a -> RegEx.Concatenation a -> RegEx.Concatenation a +(-:) pattern = (Repeatable.one pattern :) + +-- | Prepend an optional 'RegEx.Pattern', to the specified 'RegEx.Concatenation'. +(?:) :: RegEx.Pattern a -> RegEx.Concatenation a -> RegEx.Concatenation a +(?:) pattern = (Repeatable.zeroOrOne pattern :) + +-- | A /non-greedy/ version of '?:'. +(??:) :: RegEx.Pattern a -> RegEx.Concatenation a -> RegEx.Concatenation a +(??:) pattern = (Repeatable.zeroOrOne' pattern :) + +-- | Prepend a 'RegEx.Pattern', repeatable zero or more times, to the specified 'RegEx.Concatenation'. +(*:) :: RegEx.Pattern a -> RegEx.Concatenation a -> RegEx.Concatenation a +(*:) pattern = (Repeatable.zeroOrMore pattern :) + +-- | A /non-greedy/ version of '*:'. +(*?:) :: RegEx.Pattern a -> RegEx.Concatenation a -> RegEx.Concatenation a +(*?:) pattern = (Repeatable.zeroOrMore' pattern :) + +-- | Prepend a 'RegEx.Pattern', repeatable one or more times, to the specified 'RegEx.Concatenation'. +(+:) :: RegEx.Pattern a -> RegEx.Concatenation a -> RegEx.Concatenation a +(+:) pattern = (Repeatable.oneOrMore pattern :) + +-- | A /non-greedy/ version of '+:'. +(+?:) :: RegEx.Pattern a -> RegEx.Concatenation a -> RegEx.Concatenation a +(+?:) pattern = (Repeatable.oneOrMore' pattern :) + +-- | Prepend a 'RegEx.Pattern', repeated a range of times, to the specified 'RegEx.Concatenation'. +( #->#:) :: (RegEx.Pattern a, Repeatable.RepetitionBounds) -> RegEx.Concatenation a -> RegEx.Concatenation a +( #->#:) (pattern, bounds) = (pattern ^#-># bounds :) + +-- | A /non-greedy/ version of '#->#:'. +( #->#?:) :: (RegEx.Pattern a, Repeatable.RepetitionBounds) -> RegEx.Concatenation a -> RegEx.Concatenation a +( #->#?:) (pattern, bounds) = (pattern ^#->#? bounds :) + +-- | Prepend a 'RegEx.Pattern', repeated at least a specified number of times, to the specified 'RegEx.Concatenation'. +( #->:) :: (RegEx.Pattern a, Repeatable.Repetitions) -> RegEx.Concatenation a -> RegEx.Concatenation a +( #->:) (pattern, fewest) = (pattern ^#-> fewest :) + +-- | A /non-greedy/ version of '#->:'. +( #->?:) :: (RegEx.Pattern a, Repeatable.Repetitions) -> RegEx.Concatenation a -> RegEx.Concatenation a +( #->?:) (pattern, fewest) = (pattern ^#->? fewest :) + +-- | Prepend a 'RegEx.Pattern', repeated a precise number of times, to the specified 'RegEx.Concatenation'. +( #:) :: (RegEx.Pattern a, Repeatable.Repetitions) -> RegEx.Concatenation a -> RegEx.Concatenation a +( #:) (pattern, r) = (pattern ^# r :) + +{- | + * Sandwiches a 'RegEx.Concatenation' between optional 'Anchor.Anchor's to construct a 'RegEx.ExtendedRegEx'. + + * Accounts for the unusual requirement to place an 'Anchor.Stern' at the start of the 'RegEx.Concatenation', or an 'Anchor.Bow' at the end. +-} +(<~>) :: + (Maybe Anchor.Anchor, Maybe Anchor.Anchor) -- ^ A specification for the anchors required around the expression. + -> RegEx.Concatenation a -- ^ The bare list of repeatable patterns to anchor. + -> RegEx.ExtendedRegEx a -- ^ The completed regex. +(bow, stern) <~> concatenation = RegEx.MkExtendedRegEx { + RegEx.bowAnchor = bow, + RegEx.concatenation = concatenation, + RegEx.sternAnchor = stern +} diff --git a/src/RegExDot/DataSpan.hs b/src/RegExDot/DataSpan.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/DataSpan.hs @@ -0,0 +1,61 @@ +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] Augments a 'Span.Span', with the specific data concerned. +-} + +module RegExDot.DataSpan( +-- * Types +-- ** Type-synonyms + DataSpan, +-- * Functions + after, + empty, + join +) where + +import Control.Arrow((***)) +import qualified RegExDot.ConsumptionBounds as ConsumptionBounds +import qualified RegExDot.Span as Span + +{- | + * Augment 'Span.Span' with a copy of the data to which it refers. + + * Similar to . +-} +type DataSpan a = ([a], Span.Span) + +-- | Constructs an empty instance, located at the specified offset. +empty :: ConsumptionBounds.DataLength -> DataSpan a +empty offset = ([], Span.empty offset) + +-- | Returns the furthest extent, i.e. the offset just after the end. +after :: DataSpan a -> ConsumptionBounds.DataLength +after = Span.after . snd + +{- | + * Condenses a list into a single value. + + * Expects a gap-free, sorted list. +-} +join :: + ConsumptionBounds.DataLength -- ^ The offset at which the concatenated match is considered to have occurred. + -> [DataSpan a] -- ^ The list to be concatenated. + -> DataSpan a +join offset = (concat *** Span.join offset) . unzip diff --git a/src/RegExDot/DataSpanTree.hs b/src/RegExDot/DataSpanTree.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/DataSpanTree.hs @@ -0,0 +1,109 @@ +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] Permits transformation of 'RegEx.MatchList', to facilitate standardisation. +-} + +module RegExDot.DataSpanTree( +-- * Types +-- ** Type-synonyms +-- DataSpanTree, +-- DataSpanTreeList, +-- * Functions + extractCaptureGroups, + flattenTreeList, + toTreeList +) where + +import Control.Applicative((<$>)) +import qualified Data.Foldable +import qualified RegExDot.ConsumptionBounds as ConsumptionBounds +import qualified RegExDot.DataSpan as DataSpan +import qualified RegExDot.RegEx as RegEx +import qualified RegExDot.Tree as Tree + +-- | Defines a similar 'Tree.Tree' to 'RegEx.Match', but with different 'Tree.Leaf's. +type DataSpanTree a = Tree.Tree (DataSpan.DataSpan a) + +-- | Defines a similar structure to 'RegEx.MatchList'. +type DataSpanTreeList a = [DataSpanTree a] + +-- | Converts a 'RegEx.MatchList' into a 'DataSpanTreeList', by transforming the 'Tree.Leaf's. +toTreeList :: RegEx.MatchList a -> DataSpanTreeList a +toTreeList = map toTree where + toTree :: RegEx.Match a -> DataSpanTree a + toTree = (toDataSpan <$>) where + toDataSpan :: RegEx.MatchedData a -> DataSpan.DataSpan a + toDataSpan (_, inputDataOffset, inputData) = (inputData, (inputDataOffset, length inputData)) + +-- | Condenses a 'DataSpanTreeList's into a list of 'DataSpan.DataSpan's, using 'DataSpan.join'. +flattenTreeList :: + ConsumptionBounds.DataLength -- ^ The offset into the input-data at which a match occurred. + -> DataSpanTreeList a -- ^ The tree to flatten. + -> [DataSpan.DataSpan a] +flattenTreeList _ [] = [] +flattenTreeList offset (tree : treeList) = flattenedTree : flattenTreeList (DataSpan.after flattenedTree) treeList where +-- flattenedTree :: DataSpan.DataSpan a + flattenedTree = DataSpan.join offset $ Data.Foldable.toList tree + +{- | + * POSIX describes the contents of /capture-groups/, as summarised in . + + * 'RegEx.Result', is a complete description of the match between 'RegEx.InputData' & RegEx.ExtendedRegEx'; this function extracts a POSIX-conformant list from it. + + * The major differences are, that: + + Only data from parenthesized sub-expressions ('RegEx.Alternatives') is captured. + + Only the /last/ repetition of a repeated sub-expression is returned. + . + + The data captured within each parenthesized sub-expression, is summarised as a single 'DataSpan.DataSpan'. + + POSIX specifies a 'Span.Span'-offset of @-1@, for sub-expressions which match zero times; cf sub-expressions which consume nothing, once. + . + @ + ("ace" Text.Regex.Posix.=~ "a(b)*c(d)?e") :: Text.Regex.Base.RegexLike.MatchArray + array (0,2) [(0,(0,3)),(1,(-1,0)),(2,(-1,0))] + + ("ace" Text.Regex.Posix.=~ "a(b*)c(d?)e") :: Text.Regex.Base.RegexLike.MatchArray + array (0,2) [(0,(0,3)),(1,(1,0)),(2,(2,0))] + @ + I consider this a poor convention, resulting from the focus of POSIX on C, which makes subsequent calculation from the list of 'DataSpan's difficult & error-prone. +-} +extractCaptureGroups :: + Bool -- ^ Whether to strictly comply with /POSIX/. + -> DataSpanTreeList a -- ^ The tree-structure from which to extract the capture-groups. + -> [DataSpan.DataSpan a] +extractCaptureGroups complyStrictlyWithPosix = extractCaptureGroups' 0 where + extractCaptureGroups' :: ConsumptionBounds.DataLength -> DataSpanTreeList a -> [DataSpan.DataSpan a] + extractCaptureGroups' _ [] = [] + extractCaptureGroups' offset (tree : treeList) = let +-- recurseHorizontallyFrom :: ConsumptionBounds.DataLength -> [DataSpan.DataSpan a] + recurseHorizontallyFrom = (`extractCaptureGroups'` treeList) + in case tree of + Tree.Leaf dataSpan -> recurseHorizontallyFrom $ DataSpan.after dataSpan + Tree.Node [] -> DataSpan.empty (if complyStrictlyWithPosix then -1 else offset) : recurseHorizontallyFrom offset --POSIX specifies an Span-offset of -1, for sub-expressions which match 0 times; cf sub-expressions which consumes nothing, once. + Tree.Node treeLists -> joinedFlattenedTreeList : (extractCaptureGroups' offset lastMatch {-recurse vertically-} ++ recurseHorizontallyFrom (DataSpan.after joinedFlattenedTreeList)) where +-- lastMatch :: DataSpanTreeList a + lastMatch = last treeLists -- . + +-- joinedFlattenedTreeList :: DataSpan.DataSpan a + joinedFlattenedTreeList = DataSpan.join offset $ flattenTreeList offset lastMatch + diff --git a/src/RegExDot/ExecutionOptions.hs b/src/RegExDot/ExecutionOptions.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/ExecutionOptions.hs @@ -0,0 +1,102 @@ +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] + + * Defines those options relating to the "RegExDot.RegEx"-runtime. + + * These tend to be options which don't affect the result, only the means by which it is achieved. + + * Whilst similar structures are present in other regex-implementations, there's no standardisation of the fields. +-} + +module RegExDot.ExecutionOptions( +-- * Types +-- ** Data-types + ExecutionOptions(..), +-- * Functions +-- ** Mutators + setVerbose +) where + +import qualified ToolShed.Defaultable as Defaultable +import qualified ToolShed.Options as Options + +-- | The switches used to control execution of the /regex/-engine. +data ExecutionOptions = MkExecutionOptions { + abortTrialRepetitionsOnInherentFailure :: Bool, -- ^ If an /alternative/ can't match, irrespective of the subsequent /RegExDot.RegEx.Concatenation/, then avoid futile trial /RegExDot.Repeatable.Repetitions/. The converse of 'checkForUnconsumableData'. + abortTrialRepetitionsOnZeroConsumption :: Bool, -- ^ Check for zero data-consumption by the @n@-th /RegExDot.Repeatable.Repeatable RegExDot.RegEx.CaptureGroup/, before attempting @n+1@. + bypassInputDataForLiberalConsumer :: Bool, -- ^ Whether to bypass reading of the input data, if the mapping to specific /RegExDot.RegEx.RepeatablePattern/s isn't required, & the /RegExDot.RegEx.ExtendedRegEx/ can consume the required quantity of anything. + catchIncompatibleAnchors :: Bool, -- ^ Avoid futile trial solutions, involving repetitions of anchored alternatives, which must consume data. + checkExistenceOfInelasticTail :: Bool, -- ^ If the /RegExDot.RegEx.ExtendedRegEx/ ends in an inelastic (zero /Star-height/) tail, confirm its existence at the end of the /RegExDot.RegEx.InputData/. + checkForUnconsumableData :: Bool, -- ^ Check whether there's no possibility of consuming some of the input data. The converse of 'abortTrialRepetitionsOnInherentFailure'. + moderateGreed :: Bool, -- ^ Greedily consume data, only up to the limit beyond which, future requirements would be compromised. + permitReorderingOfAlternatives :: Bool, -- ^ Permit /RegExDot.RegEx.Alternatives/ to be re-ordered, in an attempt to more quickly locate a result. + preferAlternativesWhichFeedTheGreedy :: Bool, -- ^ Within the /RegExDot.RegEx.MatchedData/ from which each candidate /RegExDot.RegEx.Match/ amongst sequences of /RegExDot.RegEx.Alternatives/, is ultimately composed, prefer /RegExDot.ConsumptionBounds.ConsumptionBounds/ of /RegExDot.RegEx.InputData/, beyond /RegExDot.Repeatable.getFewest/, by /RegExDot.Repeatable.isGreedy RegExDot.RegEx.RepeatablePattern/s. + preferAlternativesWhichMimickUnrolling :: Bool, -- ^ Compare /RegExDot.ConsumptionBounds.ConsumptionBounds/ on successive /RegExDot.Repeatable.Repetitions/ of /RegExDot.RegEx.CaptureGroup/, between candidate /RegExDot.RegEx.Match/es, to mimic the behaviour of the unrolled /RegExDot.Repeatable.Repetitions/. + preferFewerRepeatedAlternatives :: Bool, -- ^ Prefer fewer /RegExDot.Repeatable.Repetitions/ of /RegExDot.RegEx.Alternatives/, to discourage the capture of null lists of /RegExDot.RegEx.InputData/. + requireMatchList :: Bool, -- ^ If merely interested in a 'Bool' result, rather than the optimal mapping of input data to /RegExDot.RegEx.RepeatablePattern/s, avoid unnecessary evaluation of the /RegEx.Match/. + unrollRepeatedSingletonAlternative :: Bool, -- ^ Check whether /RegExDot.RegEx.Alternatives/ consists of just a singleton /RegExDot.RegEx.ExtendedRegEx/, & has therefore been used merely as a capture-group. Though this doesn't affect the result, it vastly improves efficiency. + useFirstMatchAmongAlternatives :: Bool, -- ^ Rather than performing an exhaustive search for the optimal choice amongst /RegExDot.RegEx.Alternatives/, merely select the first that matches; conform to /Perl/ rather than /POSIX/. + validateMinConsumptionOfAlternatives :: Bool -- ^ When the number of repetitions of a /RegExDot.RegEx.CaptureGroup/ is precisely specified, check whether the resulting minimum data-requirement is available. +} deriving (Eq, Show) + +instance Defaultable.Defaultable ExecutionOptions where + defaultValue = setVerbose False $ Options.blankValue { + abortTrialRepetitionsOnInherentFailure = True, --Regrettably, this slightly reduces performance for most non-pathological patterns. + catchIncompatibleAnchors = True, + checkExistenceOfInelasticTail = True, + checkForUnconsumableData = True, --Expensive, particularly when (not requireMatchList), & only typically useful in failure-scenarios. + moderateGreed = True, --Cost may exceed benefit. TODO: confirm. + preferAlternativesWhichFeedTheGreedy = True, + preferAlternativesWhichMimickUnrolling = True, + preferFewerRepeatedAlternatives = True, + unrollRepeatedSingletonAlternative = True, --Affects only efficiency, not the result. + useFirstMatchAmongAlternatives = False, --Perl-style matching may be faster, but may also yield a sub-optimal Match. + validateMinConsumptionOfAlternatives = False --The cost outweighs the small infrequent dividend. + } + +instance Options.Options ExecutionOptions where + blankValue = MkExecutionOptions { + abortTrialRepetitionsOnInherentFailure = undefined, + abortTrialRepetitionsOnZeroConsumption = undefined, + bypassInputDataForLiberalConsumer = undefined, + catchIncompatibleAnchors = undefined, + checkExistenceOfInelasticTail = undefined, + checkForUnconsumableData = undefined, + moderateGreed = undefined, + permitReorderingOfAlternatives = undefined, + preferAlternativesWhichFeedTheGreedy = undefined, + preferAlternativesWhichMimickUnrolling = undefined, + preferFewerRepeatedAlternatives = undefined, + requireMatchList = undefined, + unrollRepeatedSingletonAlternative = undefined, + useFirstMatchAmongAlternatives = undefined, + validateMinConsumptionOfAlternatives = undefined + } + +-- | Sets those fields which depend crucially on whether the caller wants to retrieve any /RegExDot.RegEx.MatchList/ from the /RegExDot.RegEx.Result/, or just query whether there is one. +setVerbose :: Bool -> ExecutionOptions -> ExecutionOptions +setVerbose verbose e = e { + abortTrialRepetitionsOnZeroConsumption = verbose, --The corresponding check, involves evaluation of a /RegExDot.RegEx.MatchList/, which is too expensive if the /RegExDot.RegEx.Matchlist/ isn't otherwise required. + bypassInputDataForLiberalConsumer = not verbose, --Potentially bypasses reading of /RegExDot.RegEx.InputData/, which is inappropriate if the mapping into a /RegExDot.RegEx.Result/ is required. + permitReorderingOfAlternatives = not verbose, --Doesn't help when 'requireMatchList', since an exhaustive search of /RegExDot.RegEx.Alternatives/, for the optimal solution, is performed. + requireMatchList = verbose +} + diff --git a/src/RegExDot/InstanceInt.hs b/src/RegExDot/InstanceInt.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/InstanceInt.hs @@ -0,0 +1,43 @@ +{-# OPTIONS_GHC -fno-warn-orphans #-} +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] Provides a default implementation of the type-classes, required for 'RegEx.ExtendedRegEx' Int. + + [@CAVEATS@] + + In contrast to the traditional regex, there's no reason to escape a 'Char', other than when referring to a /shortcut/. + Since no /shortcuts/ are defined in this minimal definition, it's always an error to escape a character. +-} + +module RegExDot.InstanceInt() where + +import qualified RegExDot.BracketExpressionMember as BracketExpressionMember +import qualified RegExDot.Meta as Meta +import qualified RegExDot.RegEx as RegEx + +instance BracketExpressionMember.ShortcutExpander Int where + findPredicate _ = Nothing + +instance Meta.ShortcutExpander Int where + expand c = error $ "RegExDot.Meta.ShortcutExpander.expand RegExDot.InstanceInt:\tunrecognised shortcut '" ++ show c ++ "'." -- A shortcut is the only legitimate reason to escape a character. + +instance RegEx.ShortcutExpander Int where + expand c = error $ "RegExDot.RegEx.ShortcutExpander.expand RegExDot.InstanceInt:\tunrecognised shortcut '" ++ show c ++ "'." -- A shortcut is the only legitimate reason to escape a character. + diff --git a/src/RegExDot/Meta.hs b/src/RegExDot/Meta.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/Meta.hs @@ -0,0 +1,150 @@ +{-# LANGUAGE CPP #-} +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] + + * Describes the set of polymorphic data, which can be matched. + + * Only permits a match against exactly one polymorphic datum, which distinguishes it from a /zero-width assertion/, like an /anchor/, /word-boundary/, or /look-ahead assertion/. + + * Designed to be used by a polymorphic /regex/-engine, to implement the traditional meta-characters; @. [] [^]@. + + * Permits /Perl-style shortcuts/ for commonly used 'Meta'-data, to be canned & assigned a single-'Char' mnemonic for subsequent reference; + the implementation of 'Read' looks for a back-slashed 'Char', for which it expects there to be a corresponding canned 'Meta'. + Since this class is polymorphic, it has no knowledge of what shortcuts might be appropriate for the chosen type-parameter, + so the expansion from the back-slashed 'Char' to corresponding 'Meta'-data, is performed through the 'expand' interface of the 'ShortcutExpander' class, which should be implemented elsewhere. +-} + +module RegExDot.Meta( +-- * Type-classes + ShortcutExpander(..), +-- * Types +-- ** Data-types + Meta(..), +-- * Constants + shortcutToken, + anyToken, + tokens, +-- * Functions +-- ** Predicates + isMatch +) where + +import qualified Control.Arrow +import qualified RegExDot.BracketExpression as BracketExpression +import qualified RegExDot.BracketExpressionMember as BracketExpressionMember +import qualified RegExDot.Consumer as Consumer +import qualified RegExDot.ConsumptionProfile as ConsumptionProfile +import qualified RegExDot.ShowablePredicate as ShowablePredicate +import qualified ToolShed.SelfValidate as SelfValidate + +#ifdef HAVE_DEEPSEQ +import Control.DeepSeq(NFData, rnf) +#else +import Control.Parallel.Strategies(NFData, rnf) +#endif + +{- | + * The interface via which /Perl-style shortcut/s are expanded, in a manner appropriate to the chosen type-parameter. + + * Since the expansion of /Perl-style shortcut/s, is more restricted inside than outside a 'BracketExpression.BracketExpression', + the former is considered to be a superclass, providing a base from which to build alternative implementations. +-} +class BracketExpressionMember.ShortcutExpander m => ShortcutExpander m where + expand :: Char -> Meta m -- ^ Expand a /Perl-style shortcut/. + +-- | Declares a polymorphic data-type. +data Meta m = + Any -- ^ Any datum matches. Equivalent to @NoneOf []@, but more efficient. CAVEAT: independent of the type-parameter @a@. + | Literal m -- ^ The datum matches, if it's equal to the specified value. Equivalent to @AnyOf [BracketExpression.Literal x]@, but more efficient. + | AnyOf (BracketExpression.BracketExpression m) -- ^ The datum matches, if 'BracketExpression.containsMatch'. + | NoneOf (BracketExpression.BracketExpression m) -- ^ The datum matches, if @not BracketExpression.containsMatch@. + | Predicate (ShowablePredicate.ShowablePredicate m) -- ^ The datum matches if 'ShowablePredicate.ShowablePredicate'. + deriving ( + Eq +-- Read, --Specialised below. +-- Show --Specialised below. + ) + +instance SelfValidate.SelfValidator (Meta m) where + isValid _ = True + +instance Show m => Show (Meta m) where + showsPrec _ Any = showChar anyToken + showsPrec _ (Literal m) = shows m + showsPrec _ (AnyOf bracketExpression) = shows bracketExpression + showsPrec _ (NoneOf bracketExpression) = showChar x . showChar BracketExpression.negationToken . showString xs where (x : xs) = show $ AnyOf bracketExpression + showsPrec _ (Predicate showablePredicate) = shows showablePredicate + +instance (ShortcutExpander m, Read m) => Read (Meta m) where + readsPrec _ [] = [] --No parse. + readsPrec _ (' ' : s) = reads s --Consume white-space. + readsPrec _ ('\t' : s) = reads s --Consume white-space. + readsPrec _ ('.' : s) = [(Any, s)] + readsPrec _ ('[' : '^' : noneOf) = Control.Arrow.first NoneOf `map` reads (fst BracketExpression.delimiterTokens : noneOf) {-Reconstruct without negation, & recurse-} + readsPrec _ anyOf@('[' : _) = Control.Arrow.first AnyOf `map` reads anyOf + readsPrec _ ('\\' : c : s) = [(expand c, s)] + readsPrec _ literal = Control.Arrow.first Literal `map` reads literal + +instance Consumer.Consumer (Meta m) where + consumptionProfile meta = let + hasSpecificDataRequirement :: Bool + hasSpecificDataRequirement = case meta of + Any -> False + NoneOf [] -> False + _ -> True + in ConsumptionProfile.MkConsumptionProfile { + ConsumptionProfile.consumptionBounds = (1, Just 1), + ConsumptionProfile.hasSpecificRequirement = hasSpecificDataRequirement, + ConsumptionProfile.canConsumeAnything = not hasSpecificDataRequirement + } + + starHeight _ = 0 + +instance NFData m => NFData (Meta m) where + rnf Any = () + rnf (Literal m) = rnf m + rnf (AnyOf bracketExpression) = rnf bracketExpression + rnf (NoneOf bracketExpression) = rnf bracketExpression + rnf (Predicate showablePredicate) = rnf showablePredicate + +-- | 'True' if the specified datum matches. +isMatch :: Eq m + => m -- ^ The input datum. + -> Meta m -- ^ The meta-entity against which the input datum is to be matched. + -> Bool -- ^ The result of the match-operation. +isMatch _ Any = True +isMatch datum (Literal literal) = datum == literal +isMatch datum (AnyOf bracketExpression) = datum `BracketExpression.containsMatch` bracketExpression +isMatch datum (NoneOf bracketExpression) = not $ datum `isMatch` AnyOf bracketExpression --This implementation leverages future enhancements to 'AnyOf'. +isMatch datum (Predicate showablePredicate) = ShowablePredicate.predicate showablePredicate datum + +-- | The token used to precede a /Perl-style shortcut/, when in the 'String'-form. +shortcutToken :: Char +shortcutToken = '\\' + +-- | The token used to denote 'Any', when in the 'String'-form. +anyToken :: Char +anyToken = '.' + +-- | The set of 'Char' to which a specific meaning is attributed, when reading from 'String'. +tokens :: String +tokens = [shortcutToken, anyToken] ++ BracketExpression.tokens + diff --git a/src/RegExDot/RegEx.hs b/src/RegExDot/RegEx.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/RegEx.hs @@ -0,0 +1,1194 @@ +{-# LANGUAGE CPP #-} +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] + + * This implementation of extended /regex/es, generalises the familiar concept of pattern-matching of character-strings, to matching lists composed from an arbitrary data-type. + The polymorphic data, from which the input data-list is composed, need only support @Eq@ & @Show@. + + * Because of the unknown stringified form of the underlying polymorphic data, + the /regex/ must be described by a comparatively verbose bracketed & comma-separated list, rather than the traditional /String/ containing Meta-characters. + Each element of this 'Concatenation' is a 'RepeatablePattern', which describes a permissible match against 'InputData'. + + * 'RepeatablePattern' can take one of two forms. + In the simplest case, it matches just a single item of the underlying polymorphic type, perhaps literally, though looser specifications also exist: + @.@ matches any input datum; @[x, y, z]@ matches any of @x@, @y@, or @z@; @[^x, y, z]@ matches anything but @x@, @y@, or @z@. + To support POSIX /ERE/s, 'RepeatablePattern' can also be a list 'Alternatives', each of which is recursively defined as an 'ExtendedRegEx', to form a tree-structure. + + * Each 'Pattern', can optionally be /quantified/ by either a traditional /greedy/, or a /Perl/-style /non-greedy/, suffix, e.g.; @[*, +, ?, {n, m}, {n,}, {n}, *?, +?, ??, {n, m}?, {n,}?]@. + + * For convenience, common specifications can be canned & assigned a single 'Char' mnemonic, for subsequent reference. + Since 'ExtendedRegEx' is polymorphic, the set of abbreviations appropriate in the context of the unspecified base-type, + must be implemented externally through the 'Meta.ShortcutExpander' interface. + This permits the use, when the type-parameter is 'Char', of /Perl-style shortcuts/ @[\\d\\D\\s\\S\\w\\W]@. + + * The algorithm, is the classic /back-tracking/ one, rather than either a /DFA/ or /NFA/. + This permits construction of 'Result' via which one can discover the deep mapping of 'InputData' into 'ExtendedRegEx', + & provides the flexibility to add the features now expected by modern /regex/-engines. + Since the type-parameter is unknown, & may represent a large object, the exponential space-complexity of creating a /DFA/ may present additional problems. + The exponential time-complexity of the /back-tracking/ algorithm is partially tamed by targeting obvious inefficiencies with specific optimisations. + + * Char-based regexen, traditionally overload the delimiters of a set of 'Alternatives' (parentheses), as a request for data-capture. + Here, in contrast, all 'RepeatablePattern's capture data, & repeated sub-expressions capture a list of data, + rather than arbitrarily recording just the last () item. + + [@REFERENCES@] + + * + + * + + * + + * + + * + + * + + * + + [@CAVEATS@] + + * Because of the definition of mutually recursive data-types, it is difficult to split this annoyingly large module, & preserve compatibility across compilers, + but it may be possible to break this cyclic dependency, by defining an interface to which one of the data-types defined here conforms. + + * Doesn't implement /Back-references/, making the definition of the 'ExtendedRegEx' context-free. + + * There's no integration with the type-classes defined in "Text.Regex.Base.RegexLike", which assumes 'Char'-based 'InputData'; + though this could be added to a specialised instance. + + * When 'Alternatives' are defined, 'Result' becomes a tree-like structure. + Unless the alternative is a singleton, the specific alternative selected in the solution is typically unknown, & therefore the /structure/ of the branch of this tree is also unknown. + This lack of clarity is compounded when the 'Alternatives' are 'Repeatable.Repeatable', since a different one may be selected on each successive repetition. + Consequently, the user can't navigate this portion of the structure in a statically defined manner, to acquire the captured data. + Despite this, & in contrast to other /regex/-engines, access to the whole data-structure is available, since it doesn't seem advantage to hide it. + The user can then either use 'extractDataFromMatch' for that element of 'Result', thus aggregating the data from sections of unknown structure, or 'show' it, as an aid to debugging. + + [@TODO@] + + * Test parallel-operation, on a 3 or more processor machine. + If 'rnf' is less effective than 'rwhnf', + then the 'NFData' context can be removed, + reducing the requirements imposed on the type-parameter 'a'. + + * Try 'Data.List.Stream' (stream-fusion), a faster drop-in replacement for 'Data.List'; possibly integrated in GHC-6.12. + + * 'ExecutionOptions.bypassInputDataForLiberalConsumer' is too restrictive. + More generally, we can test whether the set of different 'a' in 'InputData', is a subset of those common to all remaining terms in the 'ExtendedRegEx'. + Using this rule, we can infer @"aaa ..." =~ MkExtendedRegEx [a,a+,a?,[ab]{2,3}]@, given compatible 'ConsumptionProfile.consumptionBounds'. + + * Nested repetitions, where nothing has been added to the expression, result in repeated trials of the same expression, + e.g.; @"(x{i,}){j,}"@ results in the same expansion for @(i, j) in [(2, 3), (3, 2), (6, 1), (1, 6)]@. + The resulting 'MatchList' may be different, but if the first such trial fails, so will all the remainder. + + * Should cope with empty sets of 'Alternatives' & zero repetitions, neither of which can ever match, but the wider pattern can, e.g. @(()|x{0}|y)@. + + * By removing 'RepeatablePattern' from 'Match', it can be isolated in a new module. + This would result in a significant loss of discoverability. + + * Expand repeated 'Anchor.Bow' with @fewest - 1@ null matches followed by recursive 'findMatch'-call with @repetitions = 1@. +-} + +module RegExDot.RegEx( +-- * Type-classes + ShortcutExpander(..), +-- * Types +-- ** Type-synonyms +-- BasicRegEx, + Concatenation, + ExternalMatch, + InputData, + MatchedData, + MatchList, +-- MetaDataList, + RepeatablePattern, +-- Transformation, +-- ** Data-types + Alternatives(..), + Match, + ExtendedRegEx(..), + Pattern(..), + Result, +-- * Constants + alternativeExtendedRegExSeparatorToken, +-- anyDatum, + captureGroupDelimiters, + tokens, +-- * Functions +-- accumulateDistinctInputData, +-- accumulateDistinctMetaDataFrom, + dock, +-- drift, +-- findMatch, + captureGroup, +-- mkNullMatchFromConcatenation, +-- mkNullMatchFromExtendedRegEx, +-- mkNullMatchFromRepeatablePattern, +-- safeReciprocal, +-- shiftMatchedData, +-- shiftMatch, + shiftMatchList, + showsMaybeAnchor, + simply, + transformExtendedRegEx, +-- ** Accessors (Deconstructors) + deconstructAlternatives, +-- getInputData, +-- ** Operators + (+~), + (=~), + (/~), + (.*), + (.*?), +-- (/+) +-- ** Predicates +-- hasBowAnchor, +-- hasSternAnchor, + isDefined, + isCaptureGroup, + isSingletonAlternatives, +-- isUnconsumableByAnyOf, +-- ** Query +-- getDistinctMetaDataFromAlternatives, +-- getDistinctMetaDataFromConcatenation, +-- getDistinctMetaDataFromExtendedRegEx, +-- getDistinctMetaDataFromPattern, +-- getDistinctMetaDataFromRepeatablePattern, + externalMatchLength, + extractDataFromMatch, + extractDataFromMatch', + extractDataFromMatchList +) where + +import Control.Applicative((<$>)) +import Control.Arrow((&&&)) +import RegExDot.Repeatable((^#->)) +import qualified Control.Arrow +import qualified Data.Char +import qualified Data.Foldable +import qualified Data.List +import qualified Data.Maybe +import qualified Data.Ord +import qualified RegExDot.Anchor as Anchor +import qualified RegExDot.Consumer as Consumer +import qualified RegExDot.ConsumptionBounds as ConsumptionBounds +import qualified RegExDot.ConsumptionProfile as ConsumptionProfile +import qualified RegExDot.ExecutionOptions as ExecutionOptions +import qualified RegExDot.Meta as Meta +import qualified RegExDot.RegExOpts as RegExOpts +import qualified RegExDot.Repeatable as Repeatable +import qualified RegExDot.Tree as Tree +import qualified ToolShed.ListPlus as ListPlus +import qualified ToolShed.SelfValidate as SelfValidate + +#if MIN_VERSION_parallel(3,0,0) +import qualified Control.Parallel.Strategies +#endif + +#ifdef HAVE_DEEPSEQ +import Control.DeepSeq(NFData, rnf) +#else +import Control.Parallel.Strategies(NFData, rnf) +#endif + +infix 4 +~, =~, /~ --Same as (==) & (/=). + +-- | The type of a /regex/, in which there's no provision for either 'Alternatives' or 'Anchor.Anchor's. +type BasicRegEx m = [Repeatable.Repeatable (Meta.Meta m)] + +{- | + * Defines the method required to expand a mnemonic into an 'ExtendedRegEx'. + + * CAVEAT: this interface must be declared locally, since it references 'ExtendedRegEx', & 'ExtendedRegEx' references it. +-} +class ShortcutExpander m where + expand :: Char -> ExtendedRegEx m -- ^ Expand a single-'Char' mnemonic into the corresponding 'ExtendedRegEx'. + +{- | + * Represents the /alternation/ feature of 'ExtendedRegEx's. + + * One could amalgamate this with 'Pattern', since it seems to exist merely as a peg to hang /instance/-declarations from. +-} +newtype Alternatives m = MkAlternatives [ExtendedRegEx m] deriving Eq + +-- | Accessor, to expose the guts. +deconstructAlternatives :: Alternatives m -> [ExtendedRegEx m] +deconstructAlternatives (MkAlternatives extendedRegExList) = extendedRegExList + +-- | Similar to 'fmap', but operates on ['ExtendedRegEx'], rather than just @a@. +transformAlternatives :: + ([ExtendedRegEx m] -> [ExtendedRegEx m]) -- ^ The transformation function to apply to the list of data behind the constructor. + -> Alternatives m + -> Alternatives m +transformAlternatives f = MkAlternatives . f . deconstructAlternatives + +instance (ShortcutExpander m, Meta.ShortcutExpander m, Eq m, Read m) => Read (Alternatives m) where + readsPrec _ (' ' : s) = reads s --Consume white-space. + readsPrec _ ('\t' : s) = reads s --Consume white-space. + readsPrec _ s = case reads s of + [(extendedRegEx, s1)] -> case dropWhile Data.Char.isSpace s1 of + ('|' : s2) -> Control.Arrow.first (transformAlternatives (extendedRegEx :)) `map` reads s2 + _ -> [(MkAlternatives [extendedRegEx], s1)] + _ -> [] --No parse. + +instance Show m => Show (Alternatives m) where + showsPrec _ = foldl (.) (showString "") . Data.List.intersperse (showChar alternativeExtendedRegExSeparatorToken) . map shows . deconstructAlternatives --Replace the default list-format, with 'egrep'-syntax. + +instance Consumer.Consumer (Alternatives m) where + consumptionProfile = Consumer.aggregateConsumptionProfilesFromAlternatives . deconstructAlternatives + starHeight = Consumer.starHeight . deconstructAlternatives --Must evaluate all Alternatives to determine best. + +instance SelfValidate.SelfValidator (Alternatives m) where + isValid = SelfValidate.isValid . deconstructAlternatives + +instance NFData m => NFData (Alternatives m) where + rnf = rnf . deconstructAlternatives + +-- | 'Alternatives' can be employed as a simple /capture-group/ as well as a switch, under which circumstances there's no choice amongst multiple 'Alternatives'. +isSingletonAlternatives :: Alternatives m -> Bool +isSingletonAlternatives = (== 1) . length . deconstructAlternatives + +-- | A set of 'Meta.Meta' which can be consumed. +type MetaDataList m = [Meta.Meta m] + +{- | + * 'True' if there's no possibility, that the specified input datum, can be consumed by any of the specified 'MetaDataList'. + + * Because data may not be consumed, perhaps because of unsuitable 'ConsumptionBounds.ConsumptionBounds', the converse doesn't hold, + ie @not isUnconsumableByAnyOf@ /doesn't/ imply that the input datum can be consumed, just that it hasn't been proven that it can't. +-} +isUnconsumableByAnyOf :: Eq m + => m -- ^ The input datum. + -> MetaDataList m -- ^ The list of meta-data against any of which a match can occur. + -> Bool +isUnconsumableByAnyOf i = not . any (Meta.isMatch i) + +-- | The set of distinct 'Meta.Meta', in the specified 'Alternatives'. +getDistinctMetaDataFromAlternatives :: Eq m => Alternatives m -> MetaDataList m +getDistinctMetaDataFromAlternatives = foldr (Data.List.union . getDistinctMetaDataFromExtendedRegEx) [] . deconstructAlternatives + +-- | Defines either a simple 'Meta.Meta', which can match exactly one datum, or a set of 'Alternatives', each of which is recursively defined above, as an 'ExtendedRegEx'. +data Pattern m = + Require (Meta.Meta m) -- ^ Describes a requirement for a simple scalar datum of the polymorphic type. + | CaptureGroup (Alternatives m) -- ^ A sub-expression containing a selection of recursively defined alternatives, thus forming a tree-structure. + deriving Eq + +instance (ShortcutExpander m, Meta.ShortcutExpander m, Eq m, Read m) => Read (Pattern m) where + readsPrec _ (' ' : s) = reads s --Consume white-space. + readsPrec _ ('\t' : s) = reads s --Consume white-space. + readsPrec _ ('(' : s) = case {-Alternatives.-} reads s of + [(alternatives, s1)] -> case dropWhile Data.Char.isSpace s1 of + (')' : s2) -> [(CaptureGroup alternatives, s2)] + _ -> [] --No parse. + _ -> [] --No parse. + readsPrec _ s = case reads s of + [pair] -> [Control.Arrow.first Require pair] + _ -> [] --No parse. + +instance Show m => Show (Pattern m) where + showsPrec _ (Require meta) = shows meta + showsPrec _ (CaptureGroup alternatives) = showChar (fst captureGroupDelimiters) . shows alternatives . showChar (snd captureGroupDelimiters) + +instance Consumer.Consumer (Pattern m) where + consumptionProfile (Require meta) = Consumer.consumptionProfile meta + consumptionProfile (CaptureGroup alternatives) = Consumer.consumptionProfile alternatives + + starHeight (Require meta) = Consumer.starHeight meta + starHeight (CaptureGroup alternatives) = Consumer.starHeight alternatives + +instance SelfValidate.SelfValidator (Pattern m) where + isValid (Require meta) = SelfValidate.isValid meta + isValid (CaptureGroup alternatives) = SelfValidate.isValid alternatives + +instance NFData m => NFData (Pattern m) where + rnf (Require meta) = rnf meta + rnf (CaptureGroup alternatives) = rnf alternatives + +-- | Convenience-function to build a 'CaptureGroup' from a list of alternative 'ExtendedRegEx's. +captureGroup :: [ExtendedRegEx m] -> Pattern m +captureGroup = CaptureGroup . MkAlternatives + +-- | 'True' if the 'Pattern' was constructed via 'CaptureGroup'. +isCaptureGroup :: Pattern m -> Bool +isCaptureGroup (CaptureGroup _) = True +isCaptureGroup _ = False + +-- | The set of distinct 'Meta.Meta', in the specified 'Pattern'. +getDistinctMetaDataFromPattern :: Eq m => Pattern m -> MetaDataList m +getDistinctMetaDataFromPattern pattern = case pattern of + Require meta -> [meta] + CaptureGroup alternatives -> getDistinctMetaDataFromAlternatives alternatives + +-- | Constant pattern, representing a lax 'Require'ment. +anyDatum :: Pattern a +anyDatum = Require Meta.Any + +-- | Make 'Pattern's, 'Repeatable.Repeatable'. +type RepeatablePattern m = Repeatable.Repeatable (Pattern m) + +-- | Construct a null 'Match' by assuming that the specified 'RepeatablePattern' consumes zero 'InputData'; of which the caller should ensure it's capable. +mkNullMatchFromRepeatablePattern :: + ConsumptionBounds.DataLength -- ^ The offset into the list of input data at which the zero-length match occurred. + -> RepeatablePattern m -- ^ The pattern that the input data matched. + -> Match m -- ^ The resulting match-structure. +mkNullMatchFromRepeatablePattern offset r = case Repeatable.base r of + Require _ -> Tree.Leaf (r, offset, []) + CaptureGroup _ -> Tree.Node $ Repeatable.getFewest r `replicate` [] + +-- | The set of distinct 'Meta.Meta', in the specified 'RepeatablePattern'. +getDistinctMetaDataFromRepeatablePattern :: Eq m => RepeatablePattern m -> MetaDataList m +getDistinctMetaDataFromRepeatablePattern = getDistinctMetaDataFromPattern . Repeatable.base + +{- | + * Represents a black hole, which will greedily consume all data. + + * CAVEAT: nullary, ie a constant. +-} +(.*) :: RepeatablePattern m +(.*) = Repeatable.zeroOrMore anyDatum + +-- | A /non-greedy/ version of '.*'. +(.*?) :: RepeatablePattern m +(.*?) = Repeatable.zeroOrMore' anyDatum + +-- | Convenience-function, to build a 'RepeatablePattern' from an unrepeated instance of the specified 'Meta.Meta'-datum. +simply :: Meta.Meta m -> RepeatablePattern m +simply = Repeatable.one . Require + +-- | Represents the /concatenation/ aspect of 'ExtendedRegEx's. +type Concatenation m = [RepeatablePattern m] + +-- | Construct a null 'Match' by assuming that the specified 'Concatenation' consumes zero 'InputData'. +mkNullMatchFromConcatenation :: + ConsumptionBounds.DataLength -- ^ The offset into the list of input data at which the zero-length match occurred. + -> Concatenation m -- ^ The list of repeatable patterns that the input data matched. + -> MatchList m -- ^ The resulting match-structure. +mkNullMatchFromConcatenation offset = map $ mkNullMatchFromRepeatablePattern offset + +-- | The set of distinct 'Meta.Meta', in the specified 'Concatenation'. +getDistinctMetaDataFromConcatenation :: Eq m => Concatenation m -> MetaDataList m +getDistinctMetaDataFromConcatenation = foldr (Data.List.union . getDistinctMetaDataFromRepeatablePattern) [] + +-- | The accumulating set of 'MetaDataList', resulting from each successive 'RepeatablePattern' in the specified 'Concatenation'. +accumulateDistinctMetaDataFrom :: Eq m => MetaDataList m -> Concatenation m -> [MetaDataList m] +accumulateDistinctMetaDataFrom = scanr (Data.List.union . getDistinctMetaDataFromRepeatablePattern) + +-- | Constructs an 'ExtendedRegEx', by surrounding a 'Concatenation' with optional 'Anchor.Anchor's. +data ExtendedRegEx m = MkExtendedRegEx { + bowAnchor :: Maybe Anchor.Anchor, -- ^ An option to anchor the /regex/ to the start of the 'InputData'. + concatenation :: Concatenation m, -- ^ The sequence of 'RepeatablePattern's defining the 'Require'ments that the 'InputData' must meet. + sternAnchor :: Maybe Anchor.Anchor -- ^ An option to anchor the /regex/ to the end of the 'InputData'. +} deriving Eq + +-- | The type of a function which transforms an 'ExtendedRegEx'. +type Transformation m = ExtendedRegEx m -> ExtendedRegEx m + +-- | Similar to 'fmap', but operates on 'Concatenation', rather than just @a@. +transformExtendedRegEx :: + (Concatenation m -> Concatenation m) -- ^ The function used to transform the data behind the constructor. + -> Transformation m +transformExtendedRegEx f extendedRegEx = extendedRegEx { concatenation = f $ concatenation extendedRegEx } + +instance (ShortcutExpander m, Meta.ShortcutExpander m, Eq m, Read m) => Read (ExtendedRegEx m) where + readsPrec _ [] = [] + readsPrec _ (' ' : s) = reads s --Consume white-space. + readsPrec _ ('\t' : s) = reads s --Consume white-space. + readsPrec _ ('\\' : c : s) = [(expand c, s)] + readsPrec _ s = (SelfValidate.isValid . fst) `filter` [ + ( + MkExtendedRegEx { + bowAnchor = maybeBowAnchor, + concatenation = concatenation', + sternAnchor = maybeSternAnchor + }, + remainder + ) | + (maybeBowAnchor, s1) <- readsMaybeAnchor s, + (concatenation', s2) <- reads s1, + (maybeSternAnchor, remainder) <- readsMaybeAnchor s2 + + ] where + readsMaybeAnchor :: ReadS (Maybe Anchor.Anchor) + readsMaybeAnchor s' = return {-to List-monad-} $ case reads s' of + [pair] -> Control.Arrow.first Just pair + _ -> (Nothing, s') + +-- | Shows either the specified 'Anchor.Anchor', or a null string where 'Nothing' is specified. +showsMaybeAnchor :: Maybe Anchor.Anchor -> String -> String +showsMaybeAnchor maybeAnchor + | Data.Maybe.isJust maybeAnchor = shows $ Data.Maybe.fromJust maybeAnchor + | otherwise = id + +instance Show m => Show (ExtendedRegEx m) where + showsPrec _ MkExtendedRegEx { + bowAnchor = maybeBowAnchor, --CAVEAT: this could be 'Nothing' or perversely an 'Anchor.Stern'. + concatenation = concatenation', + sternAnchor = maybeSternAnchor --CAVEAT: this could be 'Nothing' or perversely an 'Anchor.Bow'. + } = showsMaybeAnchor maybeBowAnchor . shows concatenation' . showsMaybeAnchor maybeSternAnchor + +instance Consumer.Consumer (ExtendedRegEx m) where + consumptionProfile = Consumer.aggregateConsumptionProfilesFromConcatenation . concatenation + starHeight = Consumer.starHeight . concatenation + +instance SelfValidate.SelfValidator (ExtendedRegEx m) where + isValid = SelfValidate.isValid {-delegate-} . concatenation --NB: null 'Concatenation' is OK. + +instance NFData m => NFData (ExtendedRegEx m) where + rnf MkExtendedRegEx { + bowAnchor = maybeBowAnchor, + concatenation = concatenation', + sternAnchor = maybeSternAnchor + } = rnf (maybeBowAnchor, concatenation', maybeSternAnchor) + +-- | Drop 'Anchor.Anchor's at both bow & stern of the specified 'ExtendedRegEx'. +dock :: Transformation m +dock e = e { + bowAnchor = Just Anchor.Bow, + sternAnchor = Just Anchor.Stern +} + +-- | Amend the 'Concatenation' in the specified 'ExtendedRegEx', by prepending '.*' where there's a missing top-level 'Anchor.Bow' & appending '.*?' where there's a missing top-level 'Anchor.Stern'. +drift :: Transformation m +drift extendedRegEx = transformExtendedRegEx ( + ( + if hasBowAnchor extendedRegEx then id else {-no anchor-} ((.*?) :) + ) . ( + if hasSternAnchor extendedRegEx then id else {-no anchor-} (++ [(.*)]) + ) + ) extendedRegEx + +-- | 'True' if the specified 'ExtendedRegEx' has an initial 'Anchor.Bow'. CAVEAT: though typically the alternative is no 'Anchor.Anchor', there may perversely be an initial 'Anchor.Stern', but neither qualify. +hasBowAnchor :: ExtendedRegEx m -> Bool +hasBowAnchor = (== Just Anchor.Bow) . bowAnchor + +-- | 'True' if the specified 'ExtendedRegEx' has a terminal 'Anchor.Stern'. CAVEAT: though typically the alternative is no 'Anchor.Anchor', there may perversely be a terminal 'Anchor.Bow', but neither qualify. +hasSternAnchor :: ExtendedRegEx m -> Bool +hasSternAnchor = (== Just Anchor.Stern) . sternAnchor + +-- | 'True' if there's at least one 'RepeatablePattern' in the 'Concatenation', ie that it's non-null. +isDefined :: ExtendedRegEx m -> Bool +isDefined = not . null . concatenation + +-- | Construct a null 'Match' by assuming that the specified 'ExtendedRegEx' consumes zero 'InputData'. +mkNullMatchFromExtendedRegEx :: ConsumptionBounds.DataLength -> ExtendedRegEx m -> MatchList m +mkNullMatchFromExtendedRegEx offset = mkNullMatchFromConcatenation offset . concatenation + +-- | The set of distinct (ie unique) 'Meta.Meta', in the specified 'ExtendedRegEx'. +getDistinctMetaDataFromExtendedRegEx :: Eq m => ExtendedRegEx m -> MetaDataList m +getDistinctMetaDataFromExtendedRegEx = getDistinctMetaDataFromConcatenation . concatenation + +{- | + * The input-data is just a list. + + * Whilst typically this list is also a 'String', & could therefore be more efficiently implemented using "Data.ByteString", + we can't assume that the polymorphic base-type is always 'Char'. +-} +type InputData m = [m] + +-- | The accumulating sets of distinct input data. +accumulateDistinctInputData :: Eq m => InputData m -> [InputData m] +accumulateDistinctInputData = scanr (Data.List.union . return) [] + +-- | Tag the 'InputData' with the 'RepeatablePattern' it matched (which unfortunately confines the definition to this (bloated) module), & the offset from the start of the data; +type MatchedData m = (RepeatablePattern m, ConsumptionBounds.DataLength, InputData m) + +-- | Shifts the offset of the specified 'MatchedData'. +shiftMatchedData :: + ConsumptionBounds.DataLength -- ^ The offset by which to shift the position into the input-data at which a match occurred. + -> MatchedData m -- ^ The match-structure whose offset is to be shifted. + -> MatchedData m +shiftMatchedData i (r, offset, d) = (r, offset + i, d) + +-- | Accessor. +getInputData :: MatchedData m -> InputData m +getInputData (_, _, inputData) = inputData + +-- | Describes the manner in which a 'RepeatablePattern' successfully consumed 'InputData'. +type Match m = Tree.Tree (MatchedData m) + +-- | Shifts the offsets of all the 'MatchedData' contained in the specified 'Match'. +shiftMatch :: + ConsumptionBounds.DataLength -- ^ The offset by which to shift the position into the input-data at which a match occurred. + -> Match m -- ^ The match-structure whose offset is to be shifted. + -> Match m +shiftMatch i = (shiftMatchedData i <$>) + +-- | Extract & concatenate, the 'InputData' from a 'Match'. +extractDataFromMatch :: Match m -> InputData m +extractDataFromMatch = Data.Foldable.foldMap getInputData --Uses the List-monoid's associative binary operator (++), to concatenate the values returned by the specified function. + +-- | Extract & concatenate, the 'InputData' from a 'Match'; null if it didn't match any. +extractDataFromMatch' :: Maybe (Match m) -> InputData m +extractDataFromMatch' (Just match) = extractDataFromMatch match +extractDataFromMatch' _ = [] + +-- | Describes the manner in which a 'Concatenation' successfully consumed 'InputData'. +type MatchList m = [Match m] + +-- | Shifts the offsets of all the 'MatchedData' contained in the specified 'MatchList'. +shiftMatchList :: + ConsumptionBounds.DataLength -- ^ The offset by which to shift the position into the input-data at which a each listed match occurred. + -> MatchList m -- ^ The list of match-structures, each of whose offsets are to be shifted. + -> MatchList m +shiftMatchList i = map (shiftMatch i) + +-- | Extract & concatenate, the 'InputData', from the 'MatchList'. +extractDataFromMatchList :: MatchList m -> InputData m +extractDataFromMatchList = concatMap extractDataFromMatch --CAVEAT: too fine-grain for effective data-parallelism. + +-- | At the top-level of an 'ExtendedRegEx', the lack of an 'Anchor.Anchor' allows the 'ExtendedRegEx' to drift away from the corresponding end of the input-data; this data-gap is captured here. +type ExternalMatch m = Maybe (Match m) + +-- | Captures the list of input-data consumed by the 'Concatenation', bracketed by any data-prefix or data-suffix. +type Result m = (ExternalMatch m, Maybe (MatchList m), ExternalMatch m) + +-- | Returns the length of data consumed by the specified 'ExternalMatch'. +externalMatchLength :: ExternalMatch m -> ConsumptionBounds.DataLength +externalMatchLength = length . extractDataFromMatch' + +{- | + * Similar to '+~', but exposes 'ExecutionOptions.ExecutionOptions', permitting greater control; & enough rope to hang yourself. + + * The parameter-order facilitates partial application, to acquire a matcher-function for a specific 'ExtendedRegEx', which can be applied repeatedly to different 'InputData'. + + * Performs some one-off @O(n)@ time-complexity preparation, then delegates the grunt-work to a private recursive function. + + * One could waste a lot of time trying to consume 'InputData' from the head of a high-'Consumer.starHeight' 'ExtendedRegEx', + only to find that there's a low-'Consumer.starHeight' tail that can't ever match the 'InputData'; checks this first before delegating. +-} +findMatch :: (Eq m, NFData m, Show m) + => RegExOpts.RegExOpts (ExtendedRegEx m) -- ^ The match-options parameterised by the regex against which to match the input data. + -> InputData m -- ^ The input data within which to locate a match. + -> Maybe (MatchList m) +findMatch regExOpts@RegExOpts.MkRegExOpts { + RegExOpts.executionOptions = executionOptions, + RegExOpts.regEx = extendedRegEx +} originalInputData + | let + extractLowStarHeightTail :: ExtendedRegEx m -> Concatenation m + extractLowStarHeightTail = {-#SCC "extractLowStarHeightTail" #-} fromConcatenation . reverse . concatenation where + fromConcatenation :: Concatenation m -> Concatenation m + fromConcatenation [] = [] + fromConcatenation (repeatablePattern : concatenation') + | Consumer.starHeight repeatablePattern == 0 = repeatablePattern : fromConcatenation {-recurse-} concatenation' + | Repeatable.getFewest repeatablePattern > 0 = case Repeatable.base repeatablePattern of + CaptureGroup alternatives + | isSingletonAlternatives alternatives -> extractLowStarHeightTail {-recurse-} . head $ deconstructAlternatives alternatives + | otherwise -> {-non-singleton-} [] + _ -> [] --Zero 'Consumer.StarHeight' would have been detected by 'fromConcatenation'. + | otherwise = [] + +-- lowStarHeightTail :: Concatenation a + lowStarHeightTail = extractLowStarHeightTail extendedRegEx + in and [ + ExecutionOptions.checkExistenceOfInelasticTail executionOptions, + not $ null lowStarHeightTail, --Prevent infinite recursion. + reverse originalInputData /~ RegExOpts.mkRegEx MkExtendedRegEx { + bowAnchor = Just Anchor.Bow, + concatenation = lowStarHeightTail, + sternAnchor = Nothing + } --Check for mismatch with the corresponding tail of 'InputData'. + ] = {-Unsafe.printShow "Tail-mismatch:\t"-} Nothing + | otherwise = findMatchSlave originalConcatenation ( + Consumer.accumulateConsumptionProfiles originalConcatenation + ) ( + accumulateDistinctMetaDataFrom [] originalConcatenation + ) originalInputData originalInputDataLength ( + accumulateDistinctInputData originalInputData + ) + where +-- originalConcatenation :: Concatenation a + originalConcatenation = concatenation extendedRegEx + + originalInputDataLength :: ConsumptionBounds.DataLength + originalInputDataLength = length originalInputData +{- + This beast takes a lot of parameters. + Whilst the only strictly necessary parameters are the lists 'Concatenation' & 'InputData', many ancillary lists derived from them, are also passed by parameter. + These are proportionally reduced on recursion, to avoid the requirement to regenerate them each time they're required. +-} + findMatchSlave :: ( + Eq m, + NFData m, + Show m + ) => Concatenation m --The list of 'RepeatablePattern's from which the regex is constructed. + -> ConsumptionProfile.AccumulatedConsumptionProfiles --The capacity-bounds for the consumption of 'InputData', that the 'Concatenation' extending right from any given 'RepeatablePattern', can consume. + -> [MetaDataList m] --The set of distinct 'Meta.Meta'-data, in the 'Concatenation extending right from any given 'RepeatablePattern'. + -> InputData m --The input data, which will be fed to the 'Concatenation'. + -> ConsumptionBounds.DataLength --The length of the previously specified 'InputData'. + -> [InputData m] --The set of distinct input data, extending right from any given point. + -> Maybe (MatchList m) + findMatchSlave [] _ _ [] _ _ = {-Unsafe.printShow "Dead heat:\t" $-} Just [] --Simultaneous exhaustion of the 'Concatenation' of 'RepeatablePattern's & the 'InputData' => success. + findMatchSlave [] _ _ _ _ _ = {-Unsafe.printShow "Excess data:\t"-} Nothing + findMatchSlave concatenation'@(repeatablePatternHead : concatenationTail) (accumulatedConsumptionProfileHead : accumulatedConsumptionProfilesTail) (distinctMetaDataHead : distinctMetaDataTail) inputData inputDataLength distinctInputData@(distinctInputDataHead : _) + | not $ inputDataLength `ConsumptionProfile.withinConsumptionBounds` accumulatedConsumptionProfileHead = {-Unsafe.printShow "outside ConsumptionBounds:\t"-} Nothing + | null inputData = Just $ mkNullMatchFromConcatenation inputDataOffset concatenation' --Build a 'Match', of null 'InputData'. + | and [ + ExecutionOptions.bypassInputDataForLiberalConsumer executionOptions, --We may be able to establish success, without evaluating 'inputData' any further than required to determine its length. + not $ ExecutionOptions.requireMatchList executionOptions, --Otherwise the precise mapping of the 'inputData' to 'RepeatablePattern's must be determined. + not $ ConsumptionProfile.hasSpecificRequirement accumulatedConsumptionProfileHead --Otherwise a match for the specific 'Meta'-data must be found. + ] = Just undefined {-shouldn't be evaluated according to 'ExecutionOptions.requireMatchList'-} + | and [ + ExecutionOptions.checkForUnconsumableData executionOptions, + not $ ConsumptionProfile.canConsumeAnything accumulatedConsumptionProfileHead, --Otherwise the subsequent test will always fail. + (`isUnconsumableByAnyOf` distinctMetaDataHead) `any` distinctInputDataHead --Occasionally failure is both inevitable & obvious. + ] = {-Unsafe.printShow ("Unconsumable data=" ++ show inputData ++ ":\t")-} Nothing + | otherwise = {-#SCC "findMatchSlave" #-} let + tailConsumptionProfile :: ConsumptionProfile.ConsumptionProfile + tailConsumptionProfile@( + ConsumptionProfile.MkConsumptionProfile { + ConsumptionProfile.consumptionBounds = (minConsumptionConcatenationTail, maybeMaxConsumptionConcatenationTail) + } + ) = {-Unsafe.printShow "tailConsumptionProfile:\t" $-} head accumulatedConsumptionProfilesTail --Extract the aggregate consumption-profile, of the tail of the 'Concatenation'. + + maxDataAvailable :: ConsumptionBounds.DataLength + maxDataAvailable = inputDataLength - minConsumptionConcatenationTail --The maximum data available to match 'repeatablePatternHead'. + in if maxDataAvailable < 0 + then {-Unsafe.printShow ("Excess Concatenation=" ++ show concatenation' ++ ":\t")-} Nothing + else {-inputData is sufficient for concatenationTail-} let + Repeatable.MkRepeatable { + Repeatable.base = base, + Repeatable.repetitionBounds = (fewest, most), + Repeatable.isGreedy = isGreedy + } = {-Unsafe.printShow "repeatablePatternHead:\t"-} repeatablePatternHead --Completely deconstruct the 'Repeatable' at the head of the 'Concatenation'. +{- + Find the maximum sequence of inputData, preceding the first of the mandatory requirements of 'concatenationTail'. + This enables one to more tightly constrain the maximum number of repetitions of a 'RepeatablePattern', + which consequently reduces the subsequent requirement to back-track. +-} +-- maximumDataBeforePegs :: Maybe (InputData m) + maximumDataBeforePegs = {-#SCC "maximumDataBeforePegs" #-} reverse ( + {-Unsafe.printShow "minimumRequirement:\t" $-} extractMinimumRequirementFromConcatenation concatenationTail + ) `maximumDataAfterPegs` reverse inputData where +{- + Extract those 'RepeatablePattern's which must match at least once. + Singleton 'Alternatives' are flattened by replication, & non-singleton 'Alternatives' removed, allowing a reduction of the list's base-type to just 'Repeatable.Repeatable' 'Meta.Meta'. + The resulting 'BasicRegEx', with /Kleene Star/s weeded-out & 'Alternatives' pruned, can be matched in O(n)-time, to verify minimal requirements. +-} + extractMinimumRequirementFromConcatenation :: Concatenation m -> BasicRegEx m + extractMinimumRequirementFromConcatenation = concatMap ( + \repeatablePattern -> case Repeatable.base repeatablePattern of + Require datum -> return {-to List-monad-} repeatablePattern { Repeatable.base = datum } + CaptureGroup a + | isSingletonAlternatives a -> concat . replicate (Repeatable.getFewest repeatablePattern) . extractMinimumRequirementFromConcatenation {-recurse-} . concatenation . head $ deconstructAlternatives a + | otherwise -> [] + ) . filter ((> 0) . Repeatable.getFewest) + + maximumDataAfterPegs :: Eq m => BasicRegEx m -> InputData m -> Maybe (InputData m) + maximumDataAfterPegs pegList@( + Repeatable.MkRepeatable { + Repeatable.base = metaPeg, + Repeatable.repetitionBounds = (fewestPeg, _) + } : pegListTail + ) inputData' + | null remainingInputData && length candidateMatchedInputData < fewestPeg = Nothing --Insufficient data to ever match. + | fewestPeg == 1 || (`Meta.isMatch` metaPeg) `all` tail candidateMatchedInputData = pegListTail `maximumDataAfterPegs` remainingInputData --Success => recurse. + | otherwise = pegList `maximumDataAfterPegs` tail candidateInputData --Failed candidate => recurse. + where +-- candidateInputData, candidateMatchedInputData, remainingInputData :: InputData a + candidateInputData = dropWhile (not . (`Meta.isMatch` metaPeg)) inputData' + (candidateMatchedInputData, remainingInputData) = fewestPeg `splitAt` candidateInputData + maximumDataAfterPegs [] inputData' = Just inputData' --All the pegs have been matched. +{- + Each 'repeatablePatternHead' can either be a 'Require' or a 'CaptureGroup'. + The former case needs further reduction & we can proceed to construct a 'Tree.Leaf' from any matching 'inputData'. + We attempt to reduce the latter case to an instance of the former, by expanding all combinations of repetitions of various 'Alternatives', constructing a new 'ExtendedRegEx' from each, & recursing. +-} + in case base of + Require meta + | null maybeMatchList -> Nothing + | otherwise -> head {-most suitable-} maybeMatchList + where +{- + Attempt to narrow the repetition-range, from the potentially unbounded specification, to that which is possible according to, + the 'inputDataLength', & the specified consumption-bounds of the remainder of the /regex/. + Once the repetition-range has been narrowed, iterate from the appropriate end of the range (depending on 'isGreedy'), extract the corresponding length from inputData, & check for a match. +-} +-- maybeMatchList :: [Maybe (MatchList m)] + maybeMatchList = {-#SCC "maybeMatchList" #-} dropWhile Data.Maybe.isNothing . {-Unsafe.printShow "maybeMatchList:\t" .-} map ( + \(consumedInputData, unconsumedInputData) -> let + consumedInputDataLength :: ConsumptionBounds.DataLength + consumedInputDataLength = {-Unsafe.printShow "consumedInputDataLength:\t" $-} length consumedInputData + in ( + Tree.Leaf (repeatablePatternHead, inputDataOffset, {-Unsafe.printShow "consumedInputData:\t"-} consumedInputData) : + ) <$> {-apply to Maybe Functor-} findMatchSlave concatenationTail accumulatedConsumptionProfilesTail distinctMetaDataTail unconsumedInputData ( + inputDataLength - consumedInputDataLength + ) ( + consumedInputDataLength `drop` distinctInputData + ) --Recurse, to check whether the 'unconsumedInputData' tail also matches. + ) $ let + fewestData, mostData, mostData' :: Repeatable.Repetitions + fewestData = {-#SCC "fewestData" #-} {-Unsafe.printShow "fewestData:\t" $-} case maybeMaxConsumptionConcatenationTail of + Just m -> (inputDataLength - m) {- :: ConsumptionBounds.DataLength-} `max` fewest {- :: Repeatable.Repetitions-} --CAVEAT: conceptually different types. + _ -> fewest + +-- mostData = length . takeWhile (~= meta) $ (`take` inputData) maxData --As slow as it is concise. + mostData = {-#SCC "mostData" #-} {-Unsafe.printShow "mostData:\t" $-} maxData - measureUnmatchableTail inputData maxData where + maxData :: ConsumptionBounds.DataLength + maxData = case most of + Just cap -> cap {-:: Repeatable.Repetitions-} `min` maxDataAvailable {-:: ConsumptionBounds.DataLength-} --CAVEAT: conceptually different types. + _ -> maxDataAvailable + +-- measureUnmatchableTail :: InputData m -> ConsumptionBounds.DataLength -> ConsumptionBounds.DataLength + measureUnmatchableTail _ 0 = 0 --Have matched all the data. + measureUnmatchableTail (a : as) unmatched + | a `Meta.isMatch` meta = measureUnmatchableTail as $ unmatched - 1 --Recurse. + | otherwise = unmatched --Return the unmatchable tail-length. + measureUnmatchableTail [] _ = error "RegExDot.RegEx.findMatch.findMatchSlave.maybeMatchList.mostData.measureUnmatchableTail:\tdata unexpectedly exhausted." +{- + 'most' has been extracted from 'repeatablePatternHead', + & reduced according to the length of 'inputData' which actually matches, to form 'mostData', + but if it still exceeds 'fewestData', the resulting repetition-range may trigger backtracking. + So, attempt to further reduce this ill-defined repetition-range, according to the competing requirements of 'concatenationTail'. +-} + mostData' + | and [ + ExecutionOptions.moderateGreed executionOptions, + isGreedy, --Otherwise, since the search proceeds from 'fewest' to 'most', the optimal solution is located before backtracking. + mostData > fewestData --Otherwise, there's no unbridled greed to moderate. + ] = case maximumDataBeforePegs of + Just maximumDataBeforePegs' -> {-Unsafe.printShow ("Reducing mostData=" ++ show mostData ++ " ->\t") $-} mostData `min` length maximumDataBeforePegs' --Cap upper bound. + _ -> {-Unsafe.printShow "Peg match-failure:\t" $-} negate 1 --Guaranteed to be < 'fewestData'. + | otherwise {-no requirement for this optimisation-} = mostData + in ( + 1 + {-fence-post-} mostData' - fewestData --CAVEAT: possibly <= 0. + ) `take` ( + if isGreedy + then ListPlus.splitsLeftFrom mostData' + else ListPlus.splitsRightFrom fewestData + ) inputData + + CaptureGroup alternatives + | and [ + not isGreedy, + fewest <= 0, --Zero repetitions permissible. + Data.Maybe.isJust tailMatch + ] {-Unsafe.printShow "Trying zero alternatives:\t"-} -> zeroRepetitions --Zero repetitions is the optimal solution, rendering the choice of Alternative irrelevant. + | and [ + ExecutionOptions.catchIncompatibleAnchors executionOptions, + fewest > 1, --Multiple repetitions. + minConsumptionAlternatives > 0, --InputData required. + ($ extendedRegExAlternatives) `any` [(hasBowAnchor `all`), (hasSternAnchor `all`)] + ] -> Nothing --'extendedRegExFromAlternative' requires 'InputData', therefore 'Anchor.Bow' can only pass on the 1st repetition & 'Anchor.Stern' can only pass on the last. + | otherwise -> let +{- + We're about to try all repetitions of one Alternative before progressing to the next. + One could alternatively transpose this search-pattern, & investigate all 'Alternatives' permissible at n repetitions, before trying (n + 1); I've not pursued this option. + Either way, if the user requires data-capture, then for POSIX-compliance we must perform an exhaustive search of the O(Alternatives ^ Repetitions) permutations for the optimal solution; though the search may be narrowed as we proceed. +-} +-- matchPairList :: [(Match m, MatchList m)] + matchPairList = {-#SCC "matchPairList" #-} Data.Maybe.catMaybes . {-Unsafe.printShow "matchPairList:\t" .-} +#if MIN_VERSION_parallel(3,0,0) + concat . Control.Parallel.Strategies.parMap Control.Parallel.Strategies.rseq --Particularly effective when 'not ExecutionOptions.requireMatchList'. +#else + concatMap +#endif + ( +-- :: ExtendedRegEx m -> [Maybe (Match m, MatchList m)] + \extendedRegExFromAlternative@MkExtendedRegEx { + concatenation = concatenationFromAlternative + } -> let + components :: Int + components = length concatenationFromAlternative + + consumptionProfileConcatenationFromAlternative :: [ConsumptionProfile.ConsumptionProfile] + consumptionProfileConcatenationFromAlternative = map Consumer.consumptionProfile concatenationFromAlternative + + minConsumptionConcatenationFromAlternative :: ConsumptionBounds.DataLength + maybeMaxConsumptionConcatenationFromAlternative :: Maybe ConsumptionBounds.DataLength + (minConsumptionConcatenationFromAlternative, maybeMaxConsumptionConcatenationFromAlternative) = ConsumptionProfile.consumptionBounds $ ConsumptionProfile.aggregateFromConcatenation consumptionProfileConcatenationFromAlternative + in ( + if ExecutionOptions.abortTrialRepetitionsOnZeroConsumption executionOptions && Data.Maybe.isNothing most {-constrained only by 'inputDataLength'-} + then {-#SCC "abortTrialRepetitionsOnZeroConsumption" #-} ListPlus.takeUntil $ \maybeMatchPair -> case maybeMatchPair of + Just (match, _) -> ($ Tree.pop match) `all` [ + (>= fewest) . length, --Must achieve 'Repeatable.getFewest', regardless of data-consumption. + null . extractDataFromMatchList . last --If the n-th repetition consumed nothing, so will the (n + 1)-th. + ] + _ -> False --Failure with n repetitions, doesn't preclude success with n + 1. + else {-optimisation not required-} id + ) . ( +-- :: Maybe (Match m, MatchList m) -> Maybe (Match m, MatchList m) + \maybeMatchPairList -> if ExecutionOptions.abortTrialRepetitionsOnInherentFailure executionOptions +{- + We're iterating through the identified range of possible repetitions, of one possible 'concatenationFromAlternative'. + If failure can be proven, for an arbitrary number of repetitions, then we can bypass the futile remainder. + If the first trial succeeded, then clearly there's no such inherent problem with 'concatenationFromAlternative', & it's necessary to evaluate all subsequent trial-repetitions. + Otherwise, assuming there're subsequent trials to be bypassed, attempt to prove that failure is inevitable, by launching a pilot-study, + using a single repetition of 'concatenationFromAlternative' followed by a replacement infallible 'concatenationTail'. +-} + then {-#SCC "abortTrialRepetitionsOnInherentFailure" #-} case maybeMatchPairList of + (Nothing {-failed attempt-} : _ {-subsequent attempt worth bypassing-} : _) -> if ( + minConsumptionConcatenationFromAlternative == 0 --Can delegate consumption of unconsumable data to the infallible tail => unprovable culpability. + ) || inputData =~ RegExOpts.mkRegEx MkExtendedRegEx { + bowAnchor = Just Anchor.Bow, + concatenation = concatenationFromAlternative ++ [anyDatum ^#-> minConsumptionConcatenationTail], --Infallible tail. + sternAnchor = Just Anchor.Stern + } + then maybeMatchPairList + else {-Unsafe.printShow ("Bypassing " ++ show (length maybeMatchPairList) ++ " repetitions; ")-} [] --Abandon further repetitions of 'Alternatives'. + _ {-Alternative is OK, or there's no subsequent attempt to bypass-} -> maybeMatchPairList + else {-optimisation not required-} maybeMatchPairList + ) . map ( +-- :: Repeatable.Repetitions -> Maybe (Match m, MatchList m) + \repetitions -> if hasSternAnchor extendedRegExFromAlternative + then if (repetitions == 1 || minConsumptionConcatenationFromAlternative == 0) && minConsumptionConcatenationTail == 0 + then ( + shiftMatch inputDataOffset . Tree.Node . ( + : replicate ( + repetitions - 1 --Typically degenerates to zero, since anchored sub-expressions aren't normally repeatable. + ) ( + mkNullMatchFromExtendedRegEx 0 extendedRegExFromAlternative --Other Alternatives may be available & suitable. + ) --Repeated null match may, lacking other suitable Alternatives, correspond to this stern-anchored ExtendedRegEx, so data must be consumed before them. + ) &&& const (mkNullMatchFromConcatenation inputDataOffset concatenationTail) + ) <$> findMatch regExOpts { RegExOpts.regEx = extendedRegExFromAlternative } inputData --Recurse, either consuming all inputData or failing. + else Nothing + else {-no Anchor.Stern-} let +{- + Expand the 'Repeatable CaptureGroup', so that after recursion it is ultimately reduced in complexity, to just a 'Concatenation' of 'Repeatable Require', & can be handled above as a POSIX BRE. + + There're two special cases; one repetition of n 'Alternatives' & n repetitions of one Alternative. + If there's only one repetition, we can reduce the implementation-logic substantially, to the point where the implementation's independent of whether there's a choice of 'Alternatives'. + If there only one Alternative, then the entire repetition-sequence can be immediately expanded, vastly reducing the required number of recursions, + otherwise we can only expand the first repetition, leaving the option of matching a different Alternative on subsequent repetitions. + + In all cases, we must subsequently re-compose any 'MatchList' resulting of the recursive call, into one corresponding to the structure of original ExtendedRegEx. + The expansion-process & corresponding subsequent collation, are associated in a tuple, in which the consumption-profile of the expansion is also contained. +-} +-- collater :: MatchList m -> (Match m, MatchList m) + consumptionProfileExpandedConcatenationPrefix :: [ConsumptionProfile.ConsumptionProfile] +-- expandedConcatenationPrefix :: Concatenation a + (collater, consumptionProfileExpandedConcatenationPrefix, expandedConcatenationPrefix) + | repetitions == 1 = ( + Control.Arrow.first ( + Tree.Node . return {-to List-monad-} + ) . splitAt components, --Bisect the 'MatchList', into the part resulting from the Alternative, & that for 'concatenationTail'. + consumptionProfileConcatenationFromAlternative, + concatenationFromAlternative + ) --Both tuples below, can degenerate to this simple case; it isn't a fundamentally different algorithm. + | and [ + ExecutionOptions.unrollRepeatedSingletonAlternative executionOptions, + isSingletonAlternative, + not $ hasBowAnchor extendedRegExFromAlternative + ] = ( + Control.Arrow.first ( + Tree.Node . ListPlus.chunk components + ) . splitAt ( + components * repetitions + ), --Bisect the 'MatchList', into the part resulting from (Alternative){n}, & that for 'concatenationTail'. + concat $ replicate repetitions consumptionProfileConcatenationFromAlternative, + concat $ replicate repetitions concatenationFromAlternative --Expand all repetitions of the single alternative. + ) + | otherwise {-choice of Alternatives or has Anchor.Bow-} = let + remainingRepetitions :: Repeatable.Repetitions + remainingRepetitions = repetitions - 1 --Expand just the first repetition of the set of 'Alternatives'. + +-- singletonRepeatable :: RepeatablePattern a + singletonRepeatable = Repeatable.toSingleton repeatablePatternHead + in ( + Control.Arrow.first ( + Tree.Node . uncurry (:) . Control.Arrow.second ( + concatMap Tree.pop --Amalgamate the repeated singleton 'MatchList's. + ) . splitAt components --Bisect first 'MatchList', into the part resulting from 'concatenationFromAlternative', & that for 'replicate remainingRepetitions'. + ) . splitAt ( + components + remainingRepetitions --Bisect the 'MatchList', into the part resulting from (Alternatives){n}, & that for 'concatenationTail'. + ), + consumptionProfileConcatenationFromAlternative ++ replicate remainingRepetitions (Consumer.consumptionProfile singletonRepeatable), + concatenationFromAlternative {-expand 1st repetition-} ++ replicate remainingRepetitions {-potentially zero-} singletonRepeatable --Enumerate all remaining repetitions of ANY Alternative; a different Alternative can match for each repetition. + ) + in {-#SCC "collater" #-} collater <$> {-apply to Maybe Functor-} findMatchSlave ( + {-Unsafe.printShow ("Expanded Alternatives for repetitions=" ++ show repetitions ++ ":\t") $-} expandedConcatenationPrefix ++ concatenationTail + ) ( + ConsumptionProfile.accumulateFrom tailConsumptionProfile {-initial value-} consumptionProfileExpandedConcatenationPrefix ++ tail accumulatedConsumptionProfilesTail + ) ( + {-Unsafe.printShow "MetaDataList:\t" $-} accumulateDistinctMetaDataFrom (head distinctMetaDataTail) {-initial value-} expandedConcatenationPrefix ++ tail distinctMetaDataTail + ) inputData inputDataLength distinctInputData --Recurse to get 'Maybe (MatchList a)'. + ) {-. Unsafe.printShow ("Range for " ++ show concatenationFromAlternative ++ ":\t")-} $ if Repeatable.isPrecise repeatablePatternHead --These are frequently generated by the previous recursion, as a trial expansion of an Alternative. + then if ExecutionOptions.validateMinConsumptionOfAlternatives executionOptions && maxDataAvailable < fewest * minConsumptionAlternatives + then {-Unsafe.printShow "Insufficient data:\t"-} [] --Failure is inevitable. + else [fewest] + else {-imprecise range-} let +{- + Attempt to narrow the repetition-range, from the potentially unbounded specification, to that which is possible according to (data available / consumption-requirement), + where there're bounds for both numerator & denominator. + Additionally, one must account for the possibility of the denominator being zero, & if so, select the optimal value if the numerator is also zero. + The range can be narrowed more aggressively, for the special case of a singleton 'Alternative', as used in a capture-group. +-} + fewestAlternatives, mostAlternatives, mostAlternatives' :: Repeatable.Repetitions + fewestAlternatives = {-#SCC "fewestAlternatives" #-} {-Unsafe.printShow "fewestAlternatives:\t" $-} 1 {-zero is handled later-} `max` if any Data.Maybe.isNothing [maybeMaxConsumptionConcatenationTail, maybeMaxConsumptionAlternatives] + then fewest + else {-no unlimited capacities-} let + minDataAvailable, maxConsumptionAlternatives :: ConsumptionBounds.DataLength + minDataAvailable = inputDataLength - Data.Maybe.fromJust maybeMaxConsumptionConcatenationTail --CAVEAT: can be negative. + maxConsumptionAlternatives = Data.Maybe.fromJust maybeMaxConsumptionAlternatives + in if isSingletonAlternative + then if maxConsumptionAlternatives == 0 --Denominator. + then {-sole Alternative can't consume anything ?!-} if minDataAvailable <= 0 --Numerator. + then {-tail may consume all data-} fewest --Repeat to meet the minimum requirement. + else {-unconsumable data-} maxBound --Failure is inevitable. + else {-non-zero => can divide-} max fewest $ minDataAvailable /+ maxConsumptionAlternatives + else {-choice of Alternatives-} let + minDataAvailable' :: ConsumptionBounds.DataLength + minDataAvailable' = minDataAvailable - Data.Maybe.fromJust maybeMaxConsumptionConcatenationFromAlternative --CAVEAT: potentially negative. + in if maxConsumptionAlternatives == 0 --Denominator. + then {-no Alternative can consume anything-} if minDataAvailable' <= 0 --Numerator. + then {-zero unconsumable data-} {-Unsafe.printShow "0/0 => fewestAlternatives:\t"-} fewest --Repeat to meet the minimum requirement. + else {-unconsumable data-} maxBound --Failure is inevitable. + else {-non-zero => can divide-} max fewest . succ {-account for expanded instance-} $ minDataAvailable' /+ maxConsumptionAlternatives + + mostAlternatives = {-#SCC "mostAlternatives" #-} {-Unsafe.printShow "mostAlternatives:\t" $-} case most of + Just cap -> cap `min` mostPermissibleRepetitions --Create a ceiling above which the calculated number of permissible repetitions can't rise. + _ -> mostPermissibleRepetitions + where + mostPermissibleRepetitions :: Repeatable.Repetitions + mostPermissibleRepetitions + | isSingletonAlternative = if minConsumptionAlternatives == 0 --Denominator. + then {-sole Alternative can consume zero data-} if maxDataAvailable == 0 --Numerator. + then {-zero data available-} fewest --Repeat to meet the minimum requirement. + else {-data available-} maxDataAvailable --Either each repetition consumes something, or (n - 1) repetitions is a better solution. + else {-non-zero => can divide-} maxDataAvailable `div` minConsumptionAlternatives --Divide & round down. + | otherwise {-choice of Alternatives-} = 1 {-account for instance expanded as 'concatenationFromAlternative'-} + let + maxDataAvailable' :: ConsumptionBounds.DataLength + maxDataAvailable' = maxDataAvailable - minConsumptionConcatenationFromAlternative --CAVEAT: potentially negative. + in if minConsumptionAlternatives == 0 --Denominator. + then {-@ least one Alternative can consume zero-} if maxDataAvailable' == 0 --Numerator. + then {-zero data available $-} fewestAlternatives - 1 --Repeat as required. CAVEAT: an annoying dependency, which prevents parallel-evaluation. + else {-data available-} if and [ + False, --The cost outweighs the small infrequent dividend. + minConsumptionConcatenationFromAlternative == 0, + maxDataAvailable > fewest + ] --If 'fewest' can be met, without unconsuming repetitions of 'concatenationFromAlternative', then stop short of permitting it. + then maxDataAvailable - 1 --Any greater, & one repetition (possibly that currently expanded) must needlessly consume nothing. + else maxDataAvailable' --Either all n repetitions consumes something, or (n - 1) is a better solution. + else {-non-zero => can divide-} maxDataAvailable' `div` minConsumptionAlternatives --Divide & round down. +{- + 'most' has been extracted from 'repeatablePatternHead', + & reduced according to the number of times it can fit into the maximum available data, to form 'mostAlternatives', + but if it still exceeds 'fewestAlternatives', the resulting repetition-range may trigger backtracking. + So, attempt to further reduce this ill-defined repetition-range, according to the competing requirements of 'concatenationTail'. + CAVEAT: this pays-off infrequently, but not necessarily insignificantly. +-} + mostAlternatives' = {-#SCC "mostAlternatives'" #-} if and [ + ExecutionOptions.moderateGreed executionOptions, + mostAlternatives > fewestAlternatives, --Otherwise, there's no unbridled greed to moderate. + minConsumptionAlternatives > 0 --Otherwise, any number of repetitions can occur without necessarily triggering back-tracking. + ] + then case maximumDataBeforePegs of + Just maximumDataBeforePegs' -> {-Unsafe.printShow ("Reducing mostAlternatives=" ++ show mostAlternatives ++ "\t-> ") $-} mostAlternatives `min` ( + length maximumDataBeforePegs' `div` minConsumptionAlternatives + ) --Cap upper bound. + _ -> {-Unsafe.printShow "Peg match-failure:\t" $-} negate 1 --Guaranteed to be < 'fewestAlternatives'. + else {-no requirement for this optimisation-} mostAlternatives + in [fewestAlternatives .. mostAlternatives'] --The permissible repetition-range of any Alternative, constrained by the amount of data available, after subtracting fixed consumption-requirements. + ) $ {-Unsafe.printShow "extendedRegExList:\t" .-} ( + if ExecutionOptions.permitReorderingOfAlternatives executionOptions +{- + The order in which 'Alternatives' are evaluated, should make no difference to the final result; unless 'ExecutionOptions.useFirstMatchAmongAlternatives'. + This order can be manipulated in an attempt to more quickly locate any 'Just MatchList', though if 'ExecutionOptions.requireMatchList', an exhaustive search for the optimal solution must be performed anyway. + Tackling lower-complexity 'Alternatives' first makes sense, in the hope of finding any easy solution before becoming entrenched fighting some hideous monster. + Preferring 'Alternatives' which require more data also makes sense, regardless of 'Repeatable.isGreedy' which just a preference for a type of solution, because fewer repetitions are then permissible; + this is rather like trying to pack a box & preferring to try the biggest items first. +-} + then Data.List.sortBy $ Data.Ord.comparing ( + Consumer.starHeight &&& safeReciprocal . (fromIntegral :: ConsumptionBounds.DataLength -> Rational) . Consumer.getFewest + ) --Firstly increasing complexity, then decreasing minimum data-capacity, otherwise stable. + else id + ) $ filter ( + \e -> ( + not (hasBowAnchor e) || inputDataOffset == 0 --Necessary & sufficient. + ) && ( + not (hasSternAnchor e) || minConsumptionConcatenationTail == 0 --Necessary but insufficient, since though minimum consumption is zero, maximum isn't necessarily. + ) + ) extendedRegExAlternatives + in if null matchPairList + then if fewest <= 0 + then {-Unsafe.printShow "Trying zero Alternatives:\t"-} zeroRepetitions --Which might still fail, depending on 'tailMatch'. + else {-zero repetitions isn't permissible-} {-Unsafe.printShow "Alternatives-mismatch:\t"-} Nothing + else {-at least one Alternative matched-} {-#SCC "selectAlternative" #-} Just . uncurry (:) {-re-join head & tail-} $ ( +{- + At least one 'Match' has been found amongst the combinations of repetitions of various 'Alternatives', + & if the caller reduces the 'Just MatchList' to 'True', that'd be sufficient, but otherwise one must identify the optimal 'MatchList'. + The primary selection-criterion used is the POSIX one, based on total maximum (or minimum for non-'Repeatable.isGreedy' capture-groups) data-consumption. + /Perl/'s "first-past-the-post" policy is available as an alternative. +-} + if ExecutionOptions.useFirstMatchAmongAlternatives executionOptions || length matchPairList == 1 + then head + else snd {-remove prepended selection-criterion-} . Data.List.maximumBy {-select the best match-} ( + Data.Ord.comparing fst --Compare using only the criterion, not the result from which it was derived. + ) . {-Unsafe.printShow "Ranked matchPairList:\t" .-} map ( + ( +{- + If the primary selection-criterion doesn't resolve the choice between candidate 'Match'es, I employ these ad-hoc criteria. +* Fewer repetitions are preferred, which discourages the capture of null lists of 'InputData'. + +* Within the 'MatchedData', from which a candidate 'Match' is ultimately composed, consumption of 'InputData' beyond 'Repeatable.getFewest' by 'Repeatable.isGreedy' 'RepeatablePattern's, is preferred to non-greedy ones. + +* The consumption on each successive repetition is compared between candidate 'Match'es (which are now known to have used an equal number of repetitions); +this causes the data-consumption to flow towards earlier repetitions for greedy capture-groups, & towards later repetitions in non-greedy ones, +thus mimicking the behaviour of the unrolled repetition. + +* PS: more precise criteria are defined in . +-} + \match -> let + dataLengthCriterion :: InputData m -> Rational + dataLengthCriterion = ( + if isGreedy + then id + else safeReciprocal --Prefer less data. + ) . fromIntegral . length + +-- matchLists :: [MatchList m] + matchLists = Tree.pop match + in ( + dataLengthCriterion $ extractDataFromMatch match, + if ExecutionOptions.preferFewerRepeatedAlternatives executionOptions + then safeReciprocal . fromIntegral $ length matchLists :: Rational + else 0, + if ExecutionOptions.preferAlternativesWhichFeedTheGreedy executionOptions + then let + excessConsumption :: MatchedData m -> ConsumptionBounds.DataLength + excessConsumption ( + Repeatable.MkRepeatable { + Repeatable.repetitionBounds = (f, _), + Repeatable.isGreedy = g + }, + _, + consumedInputData + ) + | g = l - f + | otherwise = f - l + where + l :: ConsumptionBounds.DataLength + l = length consumedInputData + in Data.Foldable.foldl' (\l -> (l +) . excessConsumption) 0 match + else 0, + if ExecutionOptions.preferAlternativesWhichMimickUnrolling executionOptions + then map (dataLengthCriterion . extractDataFromMatchList) matchLists + else [] + ) --Create a tuple of selection-criteria, for simultaneous assessment. + ) . fst {-focus the choice on the Alternatives-} &&& id --Prepend a selection-criterion to each result. + ) + ) matchPairList + where +-- tailMatch, zeroRepetitions :: Maybe (MatchList m) + tailMatch = findMatchSlave concatenationTail accumulatedConsumptionProfilesTail distinctMetaDataTail inputData inputDataLength distinctInputData --Recurse. + zeroRepetitions = (Tree.Node [] :) <$> {-apply to Maybe Functor-} tailMatch --Prepend a null 'MatchList'. + +-- extendedRegExAlternatives :: [ExtendedRegEx m] + extendedRegExAlternatives = Data.List.nub $ deconstructAlternatives alternatives + + isSingletonAlternative :: Bool + isSingletonAlternative = length extendedRegExAlternatives == 1 + + minConsumptionAlternatives :: ConsumptionBounds.DataLength + maybeMaxConsumptionAlternatives :: Maybe ConsumptionBounds.DataLength + (minConsumptionAlternatives, maybeMaxConsumptionAlternatives) = Consumer.getConsumptionBounds alternatives --Independent of the choice of Alternative. + where + inputDataOffset :: ConsumptionBounds.DataLength + inputDataOffset = originalInputDataLength - inputDataLength + findMatchSlave _ _ _ _ _ _ = error "RegExDot.RegEx.findMatch.findMatchSlave:\tunexpected parameter-pattern." + +{- | + * Operator's name was chosen to suggest something more than '=~'. + + * CAVEAT: much more expensive then '=~': in /ghci/, 'Just' can be observed to be printed /long/ before the 'MatchList' from which 'Result' is constructed, + as the lazy algorithm finds the first solution, but not yet necessarily the optimal solution, amongst 'Alternatives'. +-} +(+~) :: (Eq m, NFData m, Show m) + => InputData m -- ^ The input data within which to locate a match. + -> RegExOpts.RegExOpts (ExtendedRegEx m) -- ^ The match-options parameterised by the regex against which to match the input data. + -> Result m +inputData +~ regExOpts = ( + if hasBowAnchor' then Nothing else head <$> maybeMatchList, --Record the first 'Match', consumed in the absence of a top-level 'Anchor.Bow'. + ( + if hasBowAnchor' then id else tail --Remove the first 'Match', since this wasn't consumed by the 'Concatenation'. + ) . ( + if hasSternAnchor' then id else init --Remove the last 'Match', since this wasn't consumed by the 'Concatenation'. + ) <$> maybeMatchList, + if hasSternAnchor' then Nothing else last <$> maybeMatchList --Record the last 'Match', consumed in the absence of a top-level 'Anchor.Stern'. + ) where +-- extendedRegEx :: ExtendedRegEx a + extendedRegEx = RegExOpts.regEx regExOpts + + hasBowAnchor', hasSternAnchor' :: Bool + hasBowAnchor' = hasBowAnchor extendedRegEx + hasSternAnchor' = hasSternAnchor extendedRegEx + +-- maybeMatchList :: Maybe (MatchList m) + maybeMatchList = fmap drift (RegExOpts.setVerbose True regExOpts) `findMatch` inputData + +{- | + * Pattern-match operator. + + * Identifier & parameter-order follow the lead of /Perl/'s pattern-match operator. + + * Considerably more efficient than '+~', since even though they are both implemented via 'findMatch', + the discovery of /any/ solution is sufficient to generate the return-value; + lazy-evaluation avoids the requirement to identify the irrelevant optimal solution. +-} +(=~) :: (Eq m, NFData m, Show m) + => InputData m -- ^ The input data within which to locate a match. + -> RegExOpts.RegExOpts (ExtendedRegEx m) -- ^ The match-options parameterised by the regex against which to match the input data. + -> Bool +inputData =~ regExOpts = Data.Maybe.isJust $ fmap drift (RegExOpts.setVerbose False regExOpts) `findMatch` inputData + +-- | Pattern-mismatch operator. +(/~) :: (Eq m, NFData m, Show m) + => InputData m -- ^ The input data within which to locate a match. + -> RegExOpts.RegExOpts (ExtendedRegEx m) -- ^ The match-options parameterised by the regex against which to match the input data. + -> Bool +(/~) inputData = not . (inputData =~) + +-- | The delimiters of 'Alternatives', when in the 'String'-form. +captureGroupDelimiters :: (Char, Char) +captureGroupDelimiters = ('(', ')') + +-- | The token used to separate alternative 'ExtendedRegEx's, when in the 'String'-form. +alternativeExtendedRegExSeparatorToken :: Char +alternativeExtendedRegExSeparatorToken = '|' + +-- | The set of 'Char' to which a specific meaning is attributed, when reading from 'String'. +tokens :: String +tokens = [fst captureGroupDelimiters, snd captureGroupDelimiters, alternativeExtendedRegExSeparatorToken] + +{- | + * Invert the specified fraction, but return 'maxBound' if the result would otherwise be infinite. + + * CAVEAT: this is an awful concept, and therefore intended for internal use only. +-} +safeReciprocal :: Fractional f => f -> f +safeReciprocal 0 = fromIntegral (maxBound :: Int) --Handle divide-by-zero error. +safeReciprocal f = recip f + +infixl 7 /+ --Same as (/). + +{- | + * Integral division, with any fractional remainder rounded-up. + + * A rather dubious requirement, so internal use only. +-} +--(/+) :: Integral i => i -> i -> i +(/+) :: + Int -- ^ Numerator. + -> Int -- ^ Denominator. + -> Int --10% faster in unoptimised code, & more in optimised. +_ /+ 0 = error "RegExDot.RegEx.(/+):\tzero denominator => infinity" +--numerator /+ denominator = ceiling ((fromIntegral numerator / fromIntegral denominator) :: Double) +numerator /+ denominator = uncurry (+) . Control.Arrow.second signum $ quotRem numerator denominator --Slightly faster. diff --git a/src/RegExDot/RegExOpts.hs b/src/RegExDot/RegExOpts.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/RegExOpts.hs @@ -0,0 +1,64 @@ +{-# LANGUAGE MultiParamTypeClasses, TypeSynonymInstances, FlexibleInstances #-} +{-# OPTIONS_GHC -fno-warn-orphans #-} + +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] + + * Provides a complete job-specification. + + * 'regEx' is polymorphic, allowing use of either /RegExDot.RegEx.ExtendedRegEx/ (which is also polymorphic) or /RegExChar.ExtendedRegExChar.ExtendedRegExChar/. +-} + +module RegExDot.RegExOpts( +-- * Types +-- ** Data-types + RegExOpts(..), +-- * Functions + mkRegEx, + setVerbose +) where + +import qualified RegExDot.CompilationOptions as CompilationOptions +import qualified RegExDot.ExecutionOptions as ExecutionOptions +import qualified ToolShed.Defaultable as Defaultable + +-- | Aggregates both 'ExecutionOptions.ExecutionOptions' & 'CompilationOptions.CompilationOptions' with a polymorphic /regex/, to form a complete job-description. +data RegExOpts a = MkRegExOpts { + compilationOptions :: CompilationOptions.CompilationOptions, -- ^ Parameters governing the result, rather than the implementation. + executionOptions :: ExecutionOptions.ExecutionOptions, -- ^ Parameters governing the implementation, rather than the result. + regEx :: a -- ^ Polymorphic, to permit specialisation either of the type of /regex/ or the type of input-data. +} deriving Show + +instance Functor RegExOpts where + fmap f regExOpts = regExOpts { regEx = f $ regEx regExOpts } + +-- | Build using 'Defaultable.defaultValue'. +mkRegEx :: a -> RegExOpts a +mkRegEx r = MkRegExOpts { + compilationOptions = Defaultable.defaultValue, + executionOptions = Defaultable.defaultValue, + regEx = r +} + +-- | Mutator, which sets an appropriate 'ExecutionOptions.ExecutionOptions', for the depth to which the caller wants to probe the resulting match. +setVerbose :: Bool -> RegExOpts a -> RegExOpts a +setVerbose verbose regExOpts = regExOpts { executionOptions = ExecutionOptions.setVerbose verbose $ executionOptions regExOpts } + diff --git a/src/RegExDot/Repeatable.hs b/src/RegExDot/Repeatable.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/Repeatable.hs @@ -0,0 +1,398 @@ +{-# LANGUAGE CPP #-} +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] + + * A data-type, which represents the permissible range of instances, of the underlying polymorphic datum. + + * Designed for use in a polymorphic /regex/-engine, which specifies patterns composed of repeated /greedy/ & /non-greedy/ sequences of /Meta/-data; + + > * + ? {fewest, most} {fewest,} {fewest} + > *? +? ?? {fewest, most}? {fewest,}? + + * In the context of /regex/es, this concept is known as /Quantification/. + + * /regex/es evolved from the minimal ability to optionally qualify the datum with a suffix. + More exotic repetition-specifications could be composed by concatenating these atomic building-blocks. + Here, I've taken the contrary top-down view, & assumed that all data are qualified by a full 'RepetitionBounds', which in most cases will degenerate into a simpler form. + + * The type of entity which is being repeated, isn't the domain of this data-type; it's polymorphic. +-} + +module RegExDot.Repeatable( +-- * Types +-- ** Type-synonyms + Repetitions, + RepetitionBounds, +-- ** Data-types + Repeatable(..), +-- * Constants +-- nonGreedyToken, + oneOrMoreToken, + rangeDelimiters, + rangeSeparatorToken, + tokens, + zeroOrMoreToken, + zeroOrOneToken, +-- * Functions + one, + oneOrMore, + oneOrMore', + zeroOrMore, + zeroOrMore', + zeroOrOne, + zeroOrOne', +-- precisely, + repeatableParser, + showSuffix, +-- ** Accessors + getFewest, + getMost, +-- ** Mutators + focus, +-- setNonGreedy, + toSingleton, +-- ** Operators + (^#->#), + (^#->#?), + (^#->), + (^#->?), + (^#), +-- ** Predicates + isPrecise, + hasPreciseBounds +) where + +import Control.Applicative((<$>), (<*>)) +import Control.Arrow((***)) +import Text.ParserCombinators.Parsec(()) +import qualified Control.Monad +import qualified Data.List +import qualified RegExDot.Consumer as Consumer +import qualified RegExDot.ConsumptionProfile as ConsumptionProfile +import qualified Text.ParserCombinators.Parsec as Parsec +import qualified ToolShed.SelfValidate as SelfValidate + +#ifdef HAVE_DEEPSEQ +import Control.DeepSeq(NFData, rnf) +#else +import Control.Parallel.Strategies(NFData, rnf) +#endif + +infix 6 ^#->#, ^#->#?, ^#->, ^#->?, ^# --A notch tighter than "DSL"s binary operators. + +-- | A number of repetitions. +type Repetitions = Int + +-- | Defines the bounds of a range of permissible repetitions. +type RepetitionBounds = (Repetitions, Maybe Repetitions) + +-- | Creates a precise 'RepetitionBounds', i.e. both lower & upper bounds on the number of 'Repetitions' are equal to the same value. +precisely :: Repetitions -> RepetitionBounds +precisely i = (i, Just i) + +-- | Predicate which is 'True' if exactly one value is permissible, ie lower & upper bounds on the number of 'Repetitions' are identical. +hasPreciseBounds :: RepetitionBounds -> Bool +hasPreciseBounds (fewest, most) = Just fewest == most + +-- | Declares a polymorphic data-type, which augments the underlying 'base' datum, with the range of times it may be used. +data Repeatable a = MkRepeatable { + base :: a, -- ^ The underlying polymorphic datum. + repetitionBounds :: RepetitionBounds, -- ^ The bounds delimiting the range of permissible repetitions, of 'base'. + isGreedy :: Bool -- ^ Whether to demand as many matching instances of 'base' as possible; or as few (AKA /lazy quantification/). +} deriving Eq + +instance Functor Repeatable where + fmap f repeatable = repeatable { base = f $ base repeatable } + +-- | 'True' if there's no choice in the number of repetitions; implemented via 'isPrecise'. +isPrecise :: Repeatable a -> Bool +isPrecise = hasPreciseBounds . repetitionBounds + +-- | Builds a parser for a specification of the number of permissible instances of the specified polymorphic parameter. +repeatableParser :: a -> Parsec.Parser (Repeatable a) +repeatableParser b = Parsec.option ( + one b --The default; there's no concept of greediness here. + ) $ do + repeatable <- Parsec.choice [ + (Parsec.char oneOrMoreToken "Repeatable.oneOrMoreToken " ++ show oneOrMoreToken) >> return {-to GenParser-monad-} (oneOrMore b), + (Parsec.char zeroOrOneToken "Repeatable.zeroOrOneToken " ++ show zeroOrOneToken) >> return {-to GenParser-monad-} (zeroOrOne b), + (Parsec.char zeroOrMoreToken "Repeatable.zeroOrMoreToken " ++ show zeroOrMoreToken) >> return {-to GenParser-monad-} (zeroOrMore b), + (b ^#->#) {-arbitrarily greedy for now-} <$> uncurry Parsec.between ( + Parsec.char *** Parsec.char $ rangeDelimiters + ) ( + do + fewest <- Parsec.skipMany Parsec.space >> (read <$> Parsec.many1 Parsec.digit "Repetition-range minimum") + most <- Parsec.skipMany Parsec.space >> Parsec.option ( + Just fewest --The default. + ) ( + do + i <- ( + Parsec.char rangeSeparatorToken "Repeatable.rangeSeparatorToken " ++ show rangeSeparatorToken + ) >> Parsec.skipMany Parsec.space >> Parsec.option Nothing {-default to open-ended range-} ( + Just . read <$> Parsec.many1 Parsec.digit "Repetition-range maximum" + ) + + Parsec.skipMany Parsec.space >> return {-to GenParser-monad-} i + ) + + return {-to GenParser-monad-} (fewest, most) + ) "Repeatable.rangeDelimiters " ++ show rangeDelimiters + ] + + g <- Parsec.option True {-the default-} $ (Parsec.char nonGreedyToken "Repeatable.nonGreedyToken " ++ show nonGreedyToken) >> return {-to GenParser-monad-} False + + return {-to GenParser-monad-} repeatable { isGreedy = g } --Correct prior assumption. + +instance Read a => Read (Repeatable a) where + readsPrec _ s = case reads s {-first, read the base-type-} of + [(base', s1)] -> (error . ("readsPrec Repeatable:\tparse-error; " ++) . show) `either` return $ Parsec.parse (Control.Monad.liftM2 (,) (repeatableParser base') Parsec.getInput) "Repeatable" s1 + _ -> [] --No parse. + +{- | + * A 'ShowS'-function for the suffix, denoting the permissible repetitions, of 'base'. + + * This function converts the internal, into the tradition /greedy/ & /non-greedy/ quantifiers of various specific varieties. +-} +showSuffix :: Repeatable a -> ShowS +showSuffix repeatable = let + showRange :: ShowS -> ShowS + showRange x = (\(begin, end) -> begin . x . end) $ (showChar *** showChar) rangeDelimiters + in ( + case repetitionBounds repeatable of + (0, Nothing) -> showChar zeroOrMoreToken + (1, Nothing) -> showChar oneOrMoreToken + (fewest, Nothing) -> showRange $ shows fewest . showChar rangeSeparatorToken + (0, Just 1) -> showChar zeroOrOneToken + (1, Just 1) -> id --CAVEAT: since there's no explicit repetition-operator, the non-greedy modifier can't be appended. + (fewest, Just most) -> showRange $ if fewest == most + then shows fewest --Single-valued range. + else shows fewest . showChar rangeSeparatorToken . shows most + ) . if ($ repeatable) `any` [isGreedy, isPrecise] {-without a range of possibilities, non-greediness is irrelevant-} + then id + else showChar nonGreedyToken --This can only be appended, if there a previous repetition-operator for it to modify. + +--Replicate the syntax, for repetition, as used in a POSIX-standard /regex/. +instance Show a => Show (Repeatable a) where + showsPrec _ repeatable = shows (base repeatable) . showSuffix repeatable + +instance Consumer.Consumer a => Consumer.Consumer (Repeatable a) where + consumptionProfile MkRepeatable { + base = b, + repetitionBounds = (fewest, most) + } = baseConsumptionProfile { + ConsumptionProfile.consumptionBounds = (fewest *) *** ((*) <$> most <*>) $ ConsumptionProfile.consumptionBounds baseConsumptionProfile --CAVEAT: special cases exist, where one or both halves of this calculation degenerate to a simpler form, but special treatment, in an attempt to improve performance, proved counterproductive. + } where + baseConsumptionProfile :: ConsumptionProfile.ConsumptionProfile + baseConsumptionProfile = Consumer.consumptionProfile b + + starHeight MkRepeatable { + base = b, + repetitionBounds = r + } = Consumer.starHeight b + if hasPreciseBounds r then 0 else 1 + +instance SelfValidate.SelfValidator a => SelfValidate.SelfValidator (Repeatable a) where + isValid MkRepeatable { + base = b, + repetitionBounds = (fewest, most), + isGreedy = g + } = and [ + SelfValidate.isValid b, --Delegate. + fewest >= 0, + case most of + Just m -> m >= fewest --Exactly zero instances is perverse, but legal. + _ -> True, + g || case most of + Just m -> fewest < m --There ought to be potential for non-greediness, where specified: the converse isn't true, since greediness isn't explicit, & may not have been wanted. + _ -> True + ] + +instance NFData a => NFData (Repeatable a) where + rnf MkRepeatable { + base = b, + repetitionBounds = r, + isGreedy = g + } = rnf (b, r, g) + +-- | Mutator. +setNonGreedy :: Repeatable a -> Repeatable a +setNonGreedy r = r { isGreedy = False } + +{- | + * Construct a greedy 'Repeatable', from a polymorphic datum, with the specified range of permissible instances. + + * The /#/s in the identifier represent the two bounds. + + * /a{f, m}/ +-} +(^#->#) :: + a -- ^ The polymorphic payload from which to construct the 'Repeatable'. + -> RepetitionBounds -- ^ The permissible repetition-bounds for the polymorphic data. + -> Repeatable a +b ^#-># bounds = MkRepeatable { + base = b, + repetitionBounds = bounds, + isGreedy = True +} + +{- | + * Construct a non-greedy version of '^#->#'. + + * /a{f, m}?/ +-} +(^#->#?) :: + a -- ^ The polymorphic payload from which to construct the 'Repeatable'. + -> RepetitionBounds -- ^ The permissible repetition-bounds for the polymorphic data. + -> Repeatable a +b ^#->#? bounds = setNonGreedy (b ^#-># bounds) + +{- | + * Construct a greedy 'Repeatable', tailored for data repeated at least the specified number of times. + + * The /#/ in the identifier represents the single bound. + + * /a{f,}/ +-} +(^#->) :: + a -- ^ The polymorphic payload from which to construct the 'Repeatable'. + -> Repetitions -- ^ The minimum permissible repetitions of the polymorphic data. + -> Repeatable a +b ^#-> fewest = b ^#-># (fewest, Nothing) + +{- | + * Construct a non-greedy version of '^#->'. + + * /a{f,}?/ +-} +(^#->?) :: + a -- ^ The polymorphic payload from which to construct the 'Repeatable'. + -> Repetitions -- ^ The minimum permissible repetitions of the polymorphic data. + -> Repeatable a +b ^#->? fewest = setNonGreedy (b ^#-> fewest) + +{- | + * Construct a 'Repeatable', tailored for data repeated a precise number of times. + + * The /#/ in the identifier represents the single bound. + + * /a{f}/ +-} +(^#) :: + a -- ^ The polymorphic payload from which to construct the 'Repeatable'. + -> Repetitions -- ^ The precise number of repetitions of the polymorphic data which is required. + -> Repeatable a +b ^# r = b ^#-># precisely r + +{- | + * Construct a 'Repeatable', tailored for unrepeated data. + + * A degenerate case of '^#'. +-} +one :: a -> Repeatable a +one = (^# 1) + +{- | + * Construct a greedy 'Repeatable', from a polymorphic datum, with 'fewest' == 0 & 'most' == 1. + + * A specific case of '^#->#'. +-} +zeroOrOne :: a -> Repeatable a +zeroOrOne = (^#-># (0, Just 1)) + +-- | Construct a non-greedy version of 'zeroOrOne'. +zeroOrOne' :: a -> Repeatable a +zeroOrOne' = setNonGreedy . zeroOrOne + +{- | + * Construct a greedy 'Repeatable', from a polymorphic datum, with 'fewest' == 0. + + * A specific case of '^#->'. +-} +zeroOrMore :: a -> Repeatable a +zeroOrMore = (^#-> 0) + +-- | Construct a non-greedy version of 'zeroOrMore'. +zeroOrMore' :: a -> Repeatable a +zeroOrMore' = setNonGreedy . zeroOrMore + +{- | + * Construct a greedy 'Repeatable', from a polymorphic datum, with lower 'RepetitionBounds' == one. + + * A specific case of '^#->'. +-} +oneOrMore :: a -> Repeatable a +oneOrMore = (^#-> 1) + +-- | Construct a non-greedy version of 'oneOrMore'. +oneOrMore' :: a -> Repeatable a +oneOrMore' = setNonGreedy . oneOrMore + +-- | Reduces a 'Repeatable', with a range of 'RepetitionBounds', to a precise number of repetitions. +focus :: Repeatable a -> Repetitions -> Repeatable a +focus r i = r { repetitionBounds = precisely i } + +{- | + * Reduces a 'Repeatable', with a range of 'RepetitionBounds', to a singleton. + + * A degenerate case of 'focus'. +-} +toSingleton :: Repeatable a -> Repeatable a +toSingleton = (`focus` 1) + +-- | Accessor. +getFewest :: Repeatable a -> Repetitions +getFewest MkRepeatable { repetitionBounds = (f, _) } = f + +-- | Accessor. +getMost :: Repeatable a -> Maybe Repetitions +getMost MkRepeatable { repetitionBounds = (_, m) } = m + +-- | The token used to denote /non-greedy/, when in the 'String'-form. +nonGreedyToken :: Char +nonGreedyToken = '?' + +{- | + * The token used to denote 'zeroOrMore', when in the 'String'-form. + + * AKA /Kleene Star/. +-} +zeroOrMoreToken :: Char +zeroOrMoreToken = '*' + +-- | The token used to denote 'zeroOrOne', when in the 'String'-form. +zeroOrOneToken :: Char +zeroOrOneToken = '?' + +-- | The token used to denote 'oneOrMore', when in the 'String'-form. +oneOrMoreToken :: Char +oneOrMoreToken = '+' + +-- | The delimiters of '^#->#', when in the 'String'-form. +rangeDelimiters :: (Char, Char) +rangeDelimiters = ('{', '}') + +-- | The token used to separate 'RepetitionBounds', when in the 'String'-form. +rangeSeparatorToken :: Char +rangeSeparatorToken = ',' + +-- | The set of 'Char' to which a specific meaning is attributed, when reading from 'String'. +tokens :: String +tokens = Data.List.nub [nonGreedyToken, zeroOrMoreToken, zeroOrOneToken, oneOrMoreToken, fst rangeDelimiters, snd rangeDelimiters, rangeSeparatorToken] + diff --git a/src/RegExDot/Result.hs b/src/RegExDot/Result.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/Result.hs @@ -0,0 +1,60 @@ +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] Tools to manipulate a 'RegEx.Result'. + + [@CAVEAT@] The data-definition remains in "RegEx", since it references 'RegEx.Match'. +-} + +module RegExDot.Result( +-- * Functions +-- ** Accessors (Deconstructors) + getMatchList, + getPreMatch, + getPostMatch, +-- ** Predicates + isMatch, +-- ** Query + countMatches +) where + +import qualified Data.Maybe +import qualified RegExDot.RegEx as RegEx + +-- | Accessor. +getPreMatch :: RegEx.Result a -> RegEx.ExternalMatch a +getPreMatch (externalMatch, _, _) = externalMatch + +-- | Accessor. +getPostMatch :: RegEx.Result a -> RegEx.ExternalMatch a +getPostMatch (_, _, externalMatch) = externalMatch + +-- | Accessor. +getMatchList :: RegEx.Result a -> Maybe (RegEx.MatchList a) +getMatchList (_, maybeMatchList, _) = maybeMatchList + +-- | 'True' if the 'RegEx.InputData' matched the 'RegEx.ExtendedRegEx'. +isMatch :: RegEx.Result a -> Bool +isMatch = Data.Maybe.isJust . getMatchList + +-- | Counts the number of top-level 'RegEx.Match'es. +countMatches :: RegEx.Result a -> Int +countMatches (_, Just matchList, _) = length matchList +countMatches _ = 0 + diff --git a/src/RegExDot/ShowablePredicate.hs b/src/RegExDot/ShowablePredicate.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/ShowablePredicate.hs @@ -0,0 +1,58 @@ +{-# LANGUAGE CPP #-} +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] Used to implement /Perl-shortcut/s, /BracketExpression/-ranges & /POSIX Character-classes/. +-} + +module RegExDot.ShowablePredicate ( +-- * Types + Predicate, +-- ** Data-types + ShowablePredicate( + MkShowablePredicate, + name, + predicate + ) +) where + +#ifdef HAVE_DEEPSEQ +import Control.DeepSeq(NFData, rnf) +#else +import Control.Parallel.Strategies(NFData, rnf) +#endif + +-- | An arbitrary polymorphic predicate function. +type Predicate a = a -> Bool + +-- | Container for both the /predicate/, & the name used in the implementation of 'Show'. +data ShowablePredicate a = MkShowablePredicate { + name :: String, -- ^ The identifier of this predicate when in string-form. + predicate :: Predicate a -- ^ The function used to determine whether an input datum matches. +} + +instance Show (ShowablePredicate a) where + showsPrec _ = showString . name + +instance Eq (ShowablePredicate a) where + l == r = name l == name r --Ignore 'predicate'. + +instance NFData (ShowablePredicate a) where + rnf = rnf . name --Ignore 'predicate'. + diff --git a/src/RegExDot/Span.hs b/src/RegExDot/Span.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/Span.hs @@ -0,0 +1,64 @@ +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] Delimits a data-sequence, via its offset & length, within a wider list. +-} + +module RegExDot.Span( +-- * Types +-- ** Type-synonyms + Span, +-- * Functions + after, + empty, + join +) where + +import Control.Arrow((***)) +import qualified RegExDot.ConsumptionBounds as ConsumptionBounds + +{- | + * The offset & length of a specific data-sequence, within a wider list. + + * Similar to . +-} +type Span = (ConsumptionBounds.DataLength {-offset-}, ConsumptionBounds.DataLength) + +-- | An empty instance, located at the specified offset. +empty :: ConsumptionBounds.DataLength -> Span +empty offset = (offset, 0) + +-- | Returns the furthest extent, i.e. the offset just after the end. +after :: Span -> ConsumptionBounds.DataLength +after = uncurry (+) + +{- | + * Condenses a list into a single value. + + * Expects a gap-free, sorted list. +-} +join :: + ConsumptionBounds.DataLength -- ^ The offset into the list of input-data to use when a null list of spans is received. + -> [Span] + -> Span +join offset [] = empty offset --The offset can't be deduced from a null list, so use the value provided. +join _ [singleton] = singleton --Merely for efficiency. +join _ spanList = head *** sum $ unzip spanList + + diff --git a/src/RegExDot/Tree.hs b/src/RegExDot/Tree.hs new file mode 100644 --- /dev/null +++ b/src/RegExDot/Tree.hs @@ -0,0 +1,86 @@ +{-# LANGUAGE CPP #-} +{- + Copyright (C) 2010 Dr. Alistair Ward + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +-} +{- | + [@AUTHOR@] Dr. Alistair Ward + + [@DESCRIPTION@] + + * Defines a specific type of tree-structure, which is composed from either a datum, or a list of Tree-lists. + + * This more general tree-structure has the shape of a regular-expression match. + + * This contrasts with the typical binary-tree, which is either empty, or contains a (left Tree, datum, right Tree). +-} + +module RegExDot.Tree( +-- * Types +-- ** Type-synonyms +-- TreeList, +-- ** Data-types + Tree(..), +-- * Functions + pop +) where + +import qualified Control.Arrow +import qualified Data.Foldable +import qualified Data.List +import qualified Data.Monoid + +#ifdef HAVE_DEEPSEQ +import Control.DeepSeq(NFData, rnf) +#else +import Control.Parallel.Strategies(NFData, rnf) +#endif + +-- | A general purpose tree-type structure. +data Tree a = + Leaf a -- ^ The payload. + | Node [TreeList a] -- ^ Recurse. NB: a list of lists is required to contain the /MatchLists/ resulting from repeated /Alternatives/. + deriving Eq + +-- | A list of 'Tree's; significant only because it is the essence of the recursive nature of 'Tree'. +type TreeList a = [Tree a] + +instance Show a => Show (Tree a) where + showsPrec _ (Leaf a) = shows a + showsPrec _ (Node treeLists) = showList treeLists + +instance Read a => Read (Tree a) where + readsPrec _ node@('[' : _) = Control.Arrow.first Node `map` readList node + readsPrec _ leaf = Control.Arrow.first Leaf `map` reads leaf + +instance NFData a => NFData (Tree a) where + rnf (Leaf a) = rnf a + rnf (Node l) = rnf l + +instance Functor Tree where + fmap f (Leaf a) = Leaf $ f a + fmap f (Node treeLists) = Node $ map (fmap {-recurse-} f `map`) treeLists + +instance Data.Foldable.Foldable Tree where + foldMap f (Leaf a) = f a --CAVEAT: 'f' should be Associative, as required by a Monoid. + foldMap f (Node treeLists) = Data.List.foldl' (Data.List.foldl' (\monoid -> (monoid `Data.Monoid.mappend`) . Data.Foldable.foldMap f)) Data.Monoid.mempty treeLists + +-- | Deconstruct the specified 'Node'; i.e. lop the apex from the 'Tree', leaving a flat top. +pop :: + Tree a -- ^ The tree from which to extract the list of trees hanging immediately beneath its apex. + -> [TreeList a] +pop (Node treeLists) = treeLists +pop _ = error "RegExDot.Tree.pop:\tunexpected Leaf" +