sbv-4.2: CHANGES.md
* Hackage: <http://hackage.haskell.org/package/sbv>
* GitHub: <http://leventerkok.github.com/sbv/>
* Latest Hackage released version: 4.2, 2015-03-17
### Version 4.2, 2015-03-17
* Add exponentiation (.^). Thanks to Daniel Wagner for contributing the code!
* Better handling of SBV_$SOLVER_OPTIONS, in particular keeping track of
proper quoting in environment variables. Thanks to Adam Foltzer for
the patch!
* Silence some hlint/ghci warnings. Thanks to Trevor Elliott for the patch!
* Haddock documentation fixes, improvements, etc.
* Change ABC default option string to %blast; "&sweep -C 5000; &syn4; &cec -s -m -C 2000"
which seems to give good results. Use SBV_ABC_OPTIONS environment variable (or
via abc.rc file and a combination of SBV_ABC_OPTIONS) to experiment.
### Version 4.1, 2015-03-06
* Add support for the ABC solver from Berkeley. Thanks to Adam Foltzer
for the required infrastructure! See: http://www.eecs.berkeley.edu/~alanmi/abc/
And Alan Mishchenko for adding infrastructure to ABC to work with SBV.
* Upgrade the Boolector connection to use a SMT-Lib2 based interaction. NB. You
need at least Boolector 2.0.6 installed!
* Tracking changes in the SMT-Lib floating-point theory. If you are
using symbolic floating-point types (i.e., SFloat and SDouble), then
you should upgrade to this version and also get a very latest (unstable)
Z3 release. See http://smtlib.cs.uiowa.edu/theories/FloatingPoint.smt2
for details.
* Introduce a new class, 'RoundingFloat', which supports floating-point
operations with arbitrary rounding-modes. Note that Haskell only allows
RoundNearestTiesToAway, but with SBV, we get all 5 IEEE754 rounding-modes
and all the basic operations ('fpAdd', 'fpMul', 'fpDiv', etc.) with these
modes.
* Allow Floating-Point RoundingMode to be symbolic as well
* Improve the example "Data/SBV/Examples/Misc/Floating.hs" to include
rounding-mode based addition example.
* Changes required to make SBV compile with GHC 7.10; mostly around instance
NFData declarations. Thanks to Iavor Diatchki for the patch.
* Export a few extra symbols from the Internals module (mainly for
Cryptol usage.)
### Version 4.0, 2015-01-22
This release mainly contains contributions from Brian Huffman, allowing
end-users to define new symbolic types, such as Word4, that SBV does not
natively support. When GHC gets type-level literals, we shall most likely
incorporate arbitrary bit-sized vectors and ints using this mechanism,
but in the interim, this release provides a means for the users to introduce
individual instances.
* Modifications to support arbitrary bit-sized vectors;
These changes have been contributed by Brian Huffman
of Galois.. Thanks Brian.
* A new example "Data/SBV/Examples/Misc/Word4.hs" showing
how users can add new symbolic types.
* Support for rotate-left/rotate-right with variable
rotation amounts. (From Brian Huffman.)
### Version 3.5, 2015-01-15
This release is mainly adding support for enumerated types in Haskell being
translated to their symbolic counterparts; instead of going completely
uninterpreted.
* Keep track of data-type details for uninterpreted sorts.
* Rework the U2Bridge example to use enumerated types.
* The "Uninterpreted" name no longer makes sense with this change, so
rework the relevant names to ensure proper internal naming.
* Add Data/SBV/Examples/Misc/Enumerate.hs as an example for demonstrating
how enumerations are translated.
* Fix a long-standing bug in the implementation of select when
translated as SMT-Lib tables. (Github issue #103.) Thanks to
Brian Huffman for reporting.
### Version 3.4, 2014-12-21
* This release is mainly addressing floating-point changes in SMT-Lib.
* Track changes in the QF_FPA logic standard; new constants and alike. If you are
using the floating-point logic, then you need a relatively new version of Z3
installed (4.3.3 or newer).
* Add unary-negation as an explicit operator. Previously, we merely used the "0-x"
semantics; but with floating point, this does not hold as 0-0 is 0, and is not -0!
(Note that negative-zero is a valid floating point value, that is different than
positive-zero; yet it compares equal to it. Sigh..)
* Similarly, add abs as a native method; to make sure we map it to fp.abs for
floating point values.
* Test suite improvements
### Version 3.3, 2014-12-05
* Implement 'safe' and 'safeWith', which statically determine all calls to 'sAssert'
being safe to execute. This way, users can pepper their programs with liberal
calls to 'sAssert' and check they are all safe in one go without further worry.
* Robustify the interface to external solvers, by making sure we catch cases where
the external solver might exist but not be runnable (library dependency missing,
for example). It is impossible to be absolutely foolproof, but we now catch a
few more cases and fail gracefully.
### Version 3.2, 2014-11-18
* Implement 'sAssert'. This adds conditional symbolic simulation, by ensuring arbitrary
boolean conditions hold during simulation; similar to ASSERT calls in other languages.
Note that failures will be detected at symbolic-simulation time, i.e., each assert will
generate a call to the external solver to ensure that the condition is never violated.
If violation is possible the user will get an error, indicating the failure conditions.
* Also implement 'sAssertCont' which allows for a programmatic way to extract/display results
for consumers of 'sAssert'. While the latter simply calls 'error' in case of an assertion
violation, the 'sAssertCont' variant takes a continuation which can be used to program
how the results should be interpreted/displayed. (This is useful for libraries built on top of
SBV.) Note that the type of the continuation is such that execution should still stop, i.e.,
once an assertion violation is detected, symbolic simulation will never continue.
* Rework/simplify the 'Mergeable' class to make sure 'sBranch' is sufficiently lazy
in case of structural merges. The original implementation was only
lazy at the Word instance, but not at lists/tuples etc. Thanks to Brian Huffman
for reporting this bug.
* Add a few constant-folding optimizations for 'sDiv'and 'sRem'
* Boolector: Modify output parser to conform to the new Boolector output format. This
means that you need at least v2.0.0 of Boolector installed if you want to use that
particular solver.
* Fix long-standing translation bug regarding boolean Ord class comparisons. (i.e.,
'False > True' etc.) While Haskell allows for this, SMT-Lib does not; and hence
we have to be careful in translating. Thanks to Brian Huffman for reporting.
* C code generation: Correctly translate square-root and fusedMA functions to C.
### Version 3.1, 2014-07-12
NB: GHC 7.8.1 and 7.8.2 has a serious bug (https://ghc.haskell.org/trac/ghc/ticket/9078)
that causes SBV to crash under heavy/repeated calls. The bug is addressed
in GHC 7.8.3; so upgrading to GHC 7.8.3 is essential for using SBV!
New features/bug-fixes in v3.1:
* Using multiple-SMT solvers in parallel:
* Added functions that let the user run multiple solvers, using asynchronous
threads. All results can be obtained (proveWithAll, proveWithAny, satWithAll),
or SBV can return the fastest result (satWithAny, allSatWithAll, allSatWithAny).
These functions are good for playing with multiple-solvers, especially on
machines with multiple-cores.
* Add function: sbvAvailableSolvers; which returns the list of solvers currently
available, as installed on the machine we are running. (Not the list that SBV
supports, but those that are actually available at run-time.) This function
is useful with the multi-solve API.
* Implement sBranch:
* sBranch is a variant of 'ite' that consults the external
SMT solver to see if a given branch condition is satisfiable
before evaluating it. This can make certain "otherwise recursive
and thus not-symbolically-terminating inputs" amenable to symbolic
simulation, if termination can be established this way. Needless
to say, this problem is always decidable as far as SBV programs
are concerned, but it does not mean the decision procedure is cheap!
Use with care.
* sBranchTimeOut config parameter can be used to curtail long runs when
sBranch is used. Of course, if time-out happens, SBV will
assume the branch is feasible, in which case symbolic-termination
may come back to bite you.)
* New API:
* Add predicate 'isSNaN' which allows testing 'SFloat'/'SDouble' values
for nan-ness. This is similar to the Prelude function 'isNaN', except
the Prelude version requires a RealFrac instance, which unfortunately is
not currently implementable for cases. (Requires trigonometric functions etc.)
Thus, we provide 'isSNaN' separately (along with the already existing
'isFPPoint') to simplify reasoning with floating-point.
* Examples:
* Add Data/SBV/Examples/Misc/SBranch.hs, to illustrate the use of sBranch.
* Bug fixes:
* Fix pipe-blocking issue, which exhibited itself in the presence of
large numbers of variables (> 10K or so). See github issue #86. Thanks
to Philipp Meyer for the fine report.
* Misc:
* Add missing SFloat/SDouble instances for SatModel class
* Explicitly support KBool as a kind, separating it from "KUnbounded False 1".
Thanks to Brian Huffman for contributing the changes. This should have no
user-visible impact, but comes in handy for internal reasons.
### Version 3.0, 2014-02-16
* Support for floating-point numbers:
* Preliminary support for IEEE-floating point arithmetic, introducing
the types `SFloat` and `SDouble`. The support is still quite new,
and Z3 is the only solver that currently features a solver for
this logic. Likely to have bugs, both at the SBV level, and at the
Z3 level; so any bug reports are welcome!
* New backend solvers:
* SBV now supports MathSAT from Fondazione Bruno Kessler and
DISI-University of Trento. See: http://mathsat.fbk.eu/
* Support all-sat calls in the presence of uninterpreted sorts:
* Implement better support for `allSat` in the presence of uninterpreted
sorts. Previously, SBV simply rejected running `allSat` queries
in the presence of uninterpreted sorts, since it was not possible
to generate a refuting model. The model returned by the SMT solver
is simply not usable, since it names constants that is not visible
in a subsequent run. Eric Seidel came up with the idea that we can
actually compute equivalence classes based on a produced model, and
assert the constraint that the new model should disallow the previously
found equivalence classes instead. The idea seems to work well
in practice, and there is also an example program demonstrating
the functionality: Examples/Uninterpreted/UISortAllSat.hs
* Programmable model extraction improvements:
* Add functions `getModelDictionary` and `getModelDictionaries`, which
provide low-level access to models returned from SMT solvers. Former
for `sat` and `prove` calls, latter for `allSat` calls. Together with
the exported utils from the `Data.SBV.Internals` module, this should
allow for expert users to dissect the models returned and do fancier
programming on top of SBV.
* Add `getModelValue`, `getModelValues`, `getModelUninterpretedValue`, and
`getModelUninterpretedValues`; which further aid in model value
extraction.
* Other:
* Allow users to specify the SMT-Lib logic to use, if necessary. SBV will
still pick the logic automatically, but users can now override that choice.
Comes in handy when playing with custom logics.
* Bug fixes:
* Address allsat-laziness issue (#78 in github issue tracker). Essentially,
simplify how all-sat is called so we can avoid calling the solver for
solutions that are not needed. Thanks to Eric Seidel for reporting.
* Examples:
* Add Data/SBV/Examples/Misc/ModelExtract.hs as a simple example for
programmable model extraction and usage.
* Add Data/SBV/Examples/Misc/Floating.hs for some FP examples.
* Use the AUFLIA logic in Examples.Existentials.Diophantine which helps
z3 complete the proof quickly. (The BV logics take too long for this problem.)
### Version 2.10, 2013-03-22
* Add support for the Boolector SMT solver
* See: http://fmv.jku.at/boolector/
* Use `import Data.SBV.Bridge.Boolector` to use Boolector from SBV
* Boolector supports QF_BV (with an without arrays). In the last
SMT-Lib competition it won both bit-vector categories. It is definitely
worth trying it out for bitvector problems.
* Changes to the library:
* Generalize types of `allDifferent` and `allEqual` to take
arbitrary EqSymbolic values. (Previously was just over SBV values.)
* Add `inRange` predicate, which checks if a value is bounded within
two others.
* Add `sElem` predicate, which checks for symbolic membership
* Add `fullAdder`: Returns the carry-over as a separate boolean bit.
* Add `fullMultiplier`: Returns both the lower and higher bits resulting
from multiplication.
* Use the SMT-Lib Bool sort to represent SBool, instead of bit-vectors of length 1.
While this is an under-the-hood mechanism that should be user-transparent, it
turns out that one can no longer write axioms that return booleans in a direct
way due to this translation. This change makes it easier to write axioms that
utilize booleans as there is now a 1-to-1 match. (Suggested by Thomas DuBuisson.)
* Solvers changes:
* Z3: Update to the new parameter naming schema of Z3. This implies that
you need to have a really recent version of Z3 installed, something
in the Z3-4.3 series.
* Examples:
* Add Examples/Uninterpreted/Shannon.hs: Demonstrating Shannon expansion,
boolean derivatives, etc.
* Bug-fixes:
* Gracefully handle the case if the backend-SMT solver does not put anything
in stdout. (Reported by Thomas DuBuisson.)
* Handle uninterpreted sort values, if they happen to be only created via
function calls, as opposed to being inputs. (Reported by Thomas DuBuisson.)
### Version 2.9, 2013-01-02
- Add support for the CVC4 SMT solver from New York University and
the University of Iowa. (http://cvc4.cs.nyu.edu/).
NB. Z3 remains the default solver for SBV. To use CVC4, use the
*With variants of the interface (i.e., proveWith, satWith, ..)
by passing cvc4 as the solver argument. (Similarly, use 'yices'
as the argument for the *With functions for invoking yices.)
- Latest release of Yices calls the SMT-Lib based solver executable
yices-smt. Updated the default value of the executable to have this
name for ease of use.
- Add an extra boolean flag to compileToSMTLib and generateSMTBenchmarks
functions to control if the translation should keep the query as is
(for SAT cases), or negate it (for PROVE cases). Previously, this value
was hard-coded to do the PROVE case only.
- Add bridge modules, to simplify use of different solvers. You can now say:
import Data.SBV.Bridge.CVC4
import Data.SBV.Bridge.Yices
import Data.SBV.Bridge.Z3
to pick the appropriate default solver. if you simply 'import Data.SBV', then
you will get the default SMT solver, which is currently Z3. The value
'defaultSMTSolver' refers to z3 (currently), and 'sbvCurrentSolver' refers
to the chosen solver as determined by the imported module. (The latter is
useful for modifying options to the SMT solver in an solver-agnostic way.)
- Various improvements to Z3 model parsing routines.
- New web page for SBV: http://leventerkok.github.com/sbv/ is now online.
### Version 2.8, 2012-11-29
- Rename the SNum class to SIntegral, and make it index over regular
types. This makes it much more useful, simplifying coding of
polymorphic symbolic functions over integral types, which is
the common case.
- Add the functions:
- sbvShiftLeft
- sbvShiftRight
which can accommodate unsigned symbolic shift amounts. Note that
one cannot use the Haskell shiftL/shiftR functions from the Bits class since
they are hard-wired to take 'Int' values as the shift amounts only.
- Add a new function 'sbvArithShiftRight', which is the same as
a shift-right, except it uses the MSB of the input as the bit to fill
in (instead of always filling in with 0 bits). Note that this is
the same as shiftRight for signed values, but differs from a shiftRight
when the input is unsigned. (There is no Haskell analogue of this
function, as Haskell shiftR is always arithmetic for signed
types and logical for unsigned ones.) This variant is designed for
use cases when one uses the underlying unsigned SMT-Lib representation
to implement custom signed operations, for instance.
- Several typo fixes.
### Version 2.7, 2012-10-21
- Add missing QuickCheck instance for SReal
- When dealing with concrete SReals, make sure to operate
only on exact algebraic reals on the Haskell side, leaving
true algebraic reals (i.e., those that are roots of polynomials
that cannot be expressed as a rational) symbolic. This avoids
issues with functions that we cannot implement directly on
the Haskell side, like exact square-roots.
- Documentation tweaks, typo fixes etc.
- Rename BVDivisible class to SDivisible; since SInteger
is also an instance of this class, and SDivisible is a
more appropriate name to start with. Also add sQuot and sRem
methods; along with sDivMod, sDiv, and sMod, with usual
semantics.
- Improve test suite, adding many constant-folding tests
and start using cabal based tests (--enable-tests option.)
### Versions 2.4, 2.5, and 2.6: Around mid October 2012
- Workaround issues related hackage compilation, in particular to the
problem with the new containers package release, which does provide
an NFData instance for sequences.
- Add explicit Num requirements when necessary, as the Bits class
no longer does this.
- Remove dependency on the hackage package strict-concurrency, as
hackage can no longer compile it due to some dependency mismatch.
- Add forgotten Real class instance for the type 'AlgReal'
- Stop putting bounds on hackage dependencies, as they cause
more trouble then they actually help. (See the discussion
here: http://www.haskell.org/pipermail/haskell-cafe/2012-July/102352.html.)
### Version 2.3, 2012-07-20
- Maintanence release, no new features.
- Tweak cabal dependencies to avoid using packages that are newer
than those that come with ghc-7.4.2. Apparently this is a no-no
that breaks many things, see the discussion in this thread:
http://www.haskell.org/pipermail/haskell-cafe/2012-July/102352.html
In particular, the use of containers >= 0.5 is *not* OK until we have
a version of GHC that comes with that version.
### Version 2.2, 2012-07-17
- Maintanence release, no new features.
- Update cabal dependencies, in particular fix the
regression with respect to latest version of the
containers package.
### Version 2.1, 2012-05-24
* Library:
* Add support for uninterpreted sorts, together with user defined
domain axioms. See Data.SBV.Examples.Uninterpreted.Sort
and Data.SBV.Examples.Uninterpreted.Deduce for basic examples of
this feature.
* Add support for C code-generation with SReals. The user picks
one of 3 possible C types for the SReal type: CgFloat, CgDouble
or CgLongDouble, using the function cgSRealType. Naturally, the
resulting C program will suffer a loss of precision, as it will
be subject to IEE-754 rounding as implied by the underlying type.
* Add toSReal :: SInteger -> SReal, which can be used to promote
symbolic integers to reals. Comes handy in mixed integer/real
computations.
* Examples:
* Recast the dog-cat-mouse example to use the solver over reals.
* Add Data.SBV.Examples.Uninterpreted.Sort, and
Data.SBV.Examples.Uninterpreted.Deduce
for illustrating uninterpreted sorts and axioms.
### Version 2.0, 2012-05-10
This is a major release of SBV, adding support for symbolic algebraic reals: SReal.
See http://en.wikipedia.org/wiki/Algebraic_number for details. In brief, algebraic
reals are solutions to univariate polynomials with rational coefficients. The arithmetic
on algebraic reals is precise, with no approximation errors. Note that algebraic reals
are a proper subset of all reals, in particular transcendental numbers are not
representable in this way. (For instance, "sqrt 2" is algebraic, but pi, e are not.)
However, algebraic reals is a superset of rationals, so SBV now also supports symbolic
rationals as well.
You *should* use Z3 v4.0 when working with real numbers. While the interface will
work with older versions of Z3 (or other SMT solvers in general), it uses Z3
root-obj construct to retrieve and query algebraic reals.
While SReal values have infinite precision, printing such values is not trivial since
we might need an infinite number of digits if the result happens to be irrational. The
user controls printing precision, by specifying how many digits after the decimal point
should be printed. The default number of decimal digits to print is 10. (See the
'printRealPrec' field of SMT-solver configuration.)
The acronym SBV used to stand for Symbolic Bit Vectors. However, SBV has grown beyond
bit-vectors, especially with the addition of support for SInteger and SReal types and
other code-generation utilities. Therefore, "SMT Based Verification" is now a better fit
for the expansion of the acronym SBV.
Other notable changes in the library:
* Add functions s[TYPE] and s[TYPE]s for each symbolic type we support (i.e.,
sBool, sBools, sWord8, sWord8s, etc.), to create symbolic variables of the
right kind. Strictly speaking these are just synonyms for 'free'
and 'mapM free' (plural versions), so they are not adding any additional
power. Except, they are specialized at their respective types, and might be
easier to remember.
* Add function solve, which is merely a synonym for (return . bAnd), but
it simplifies expressing problems.
* Add class SNum, which simplifies writing polymorphic code over symbolic values
* Increase haddock coverage metrics
* Major code refactoring around symbolic kinds
* SMTLib2: Emit ":produce-models" call before setting the logic, as required
by the SMT-Lib2 standard. [Patch provided by arrowdodger on github, thanks!]
Bugs fixed:
* [Performance] Use a much simpler default definition for "select": While the
older version (based on binary search on the bits of the indexer) was correct,
it created unnecessarily big expressions. Since SBV does not have a notion
of concrete subwords, the binary-search trick was not bringing any advantage
in any case. Instead, we now simply use a linear walk over the elements.
Examples:
* Change dog-cat-mouse example to use SInteger for the counts
* Add merge-sort example: Data.SBV.Examples.BitPrecise.MergeSort
* Add diophantine solver example: Data.SBV.Examples.Existentials.Diophantine
### Version 1.4, 2012-05-10
* Interim release for test purposes
### Version 1.3, 2012-02-25
* Workaround cabal/hackage issue, functionally the same as release
1.2 below
### Version 1.2, 2012-02-25
Library:
* Add a hook so users can add custom script segments for SMT solvers. The new
"solverTweaks" field in the SMTConfig data-type can be used for this purpose.
The need for this came about due to the need to workaround a Z3 v3.2 issue
detalied below:
http://stackoverflow.com/questions/9426420/soundness-issue-with-integer-bv-mixed-benchmarks
As a consequence, mixed Integer/BV problems can cause soundness issues in Z3
and does in SBV. Unfortunately, it is too severe for SBV to add the woraround
option, as it slows down the solver as a side effect as well. Thus, we are
making this optionally available if/when needed. (Note that the work-around
should not be necessary with Z3 v3.3; which is not released yet.)
* Other minor clean-up
### Version 1.1, 2012-02-14
Library:
* Rename bitValue to sbvTestBit
* Add sbvPopCount
* Add a custom implementation of 'popCount' for the Bits class
instance of SBV (GHC >= 7.4.1 only)
* Add 'sbvCheckSolverInstallation', which can be used to check
that the given solver is installed and good to go.
* Add 'generateSMTBenchmarks', simplifying the generation of
SMTLib benchmarks for offline sharing.
### Version 1.0, 2012-02-13
Library:
* Z3 is now the "default" SMT solver. Yices is still available, but
has to be specifically selected. (Use satWith, allSatWith, proveWith, etc.)
* Better handling of the pConstrain probability threshold for test
case generation and quickCheck purposes.
* Add 'renderTest', which accompanies 'genTest' to render test
vectors as Haskell/C/Forte program segments.
* Add 'expectedValue' which can compute the expected value of
a symbolic value under the given constraints. Useful for statistical
analysis and probability computations.
* When saturating provable values, use forAll_ for proofs and forSome_
for sat/allSat. (Previously we were allways using forAll_, which is
not incorrect but less intuitive.)
* add function:
extractModels :: SatModel a => AllSatResult -> [a]
which simplifies accessing allSat results greatly.
Code-generation:
* add "cgGenerateMakefile" which allows the user to choose if SBV
should generate a Makefile. (default: True)
Other
* Changes to make it compile with GHC 7.4.1.
### Version 0.9.24, 2011-12-28
Library:
* Add "forSome," analogous to "forAll." (The name "exists" would've
been better, but it's already taken.) This is not as useful as
one might think as forAll and forSome do not nest, as an inner
application of one pushes its argument to a Predicate, making
the outer one useless, but it is nonetheless useful by itself.
* Add a "Modelable" class, which simplifies model extraction.
* Add support for quick-check at the "Symbolic SBool" level. Previously
SBV only allowed functions returning SBool to be quick-checked, which
forced a certain style of coding. In particular with the addition
of quantifiers, the new coding style mostly puts the top-level
expressions in the Symbolic monad, which were not quick-checkable
before. With new support, the quickCheck, prove, sat, and allSat
commands are all interchangeable with obvious meanings.
* Add support for concrete test case generation, see the genTest function.
* Improve optimize routines and add support for iterative optimization.
* Add "constrain", simplifying conjunctive constraints, especially
useful for adding constraints at variable generation time via
forall/exists. Note that the interpretation of such constraints
is different for genTest and quickCheck functions, where constraints
will be used for appropriately filtering acceptable test values
in those two cases.
* Add "pConstrain", which probabilistically adds constraints. This
is useful for quickCheck and genTest functions for filtering acceptable
test values. (Calls to pConstrain will be rejected for sat/prove calls.)
* Add "isVacuous" which can be used to check that the constraints added
via constrain are satisfable. This is useful to prevent vacuous passes,
i.e., when a proof is not just passing because the constraints imposed
are inconsistent. (Also added accompanying isVacuousWith.)
* Add "free" and "free_", analogous to "forall/forall_" and "exists/exists_"
The difference is that free behaves universally in a proof context, while
it behaves existentially in a sat context. This allows us to express
properties more succinctly, since the intended semantics is usually this
way depending on the context. (i.e., in a proof, we want our variables
universal, in a sat call existential.) Of course, exists/forall are still
available when mixed quantifiers are needed, or when the user wants to
be explicit about the quantifiers.
Examples
* Add Data/SBV/Examples/Puzzles/Coins.hs. (Shows the usage of "constrain".)
Dependencies
* Bump up random package dependency to 1.0.1.1 (from 1.0.0.2)
Internal
* Major reorganization of files to and build infrastructure to
decrease build times and better layout
* Get rid of custom Setup.hs, just use simple build. The extra work
was not worth the complexity.
### Version 0.9.23, 2011-12-05
Library:
* Add support for SInteger, the type of signed unbounded integer
values. SBV can now prove theorems about unbounded numbers,
following the semantics of Haskell Integer type. (Requires z3 to
be used as the backend solver.)
* Add functions 'optimize', 'maximize', and 'minimize' that can
be used to find optimal solutions to given constraints with
respect to a given cost function.
* Add 'cgUninterpret', which simplifies code generation when we want
to use an alternate definition in the target language (i.e., C). This
is important for efficient code generation, when we want to
take advantage of native libraries available in the target platform.
Other:
* Change getModel to return a tuple in the success case, where
the first component is a boolean indicating whether the model
is "potential." This is used to indicate that the solver
actually returned "unknown" for the problem and the model
might therefore be bogus. Note that we did not need this before
since we only supported bounded bit-vectors, which has a decidable
theory. With the addition of unbounded Integers and quantifiers, the
solvers can now return unknown. This should still be rare in practice,
but can happen with the use of non-linear constructs. (i.e.,
multiplication of two variables.)
### Version 0.9.22, 2011-11-13
The major change in this release is the support for quantifiers. The
SBV library *no* longer assumes all variables are universals in a proof,
(and correspondingly existential in a sat) call. Instead, the user
marks free-variables appropriately using forall/exists functions, and the
solver translates them accordingly. Note that this is a non-backwards
compatible change in sat calls, as the semantics of formulas is essentially
changing. While this is unfortunate, it is more uniform and simpler to understand
in general.
This release also adds support for the Z3 solver, which is the main
SMT-solver used for solving formulas involving quantifiers. More formally,
we use the new AUFBV/ABV/UFBV logics when quantifiers are involved. Also,
the communication with Z3 is now done via SMT-Lib2 format. Eventually
the SMTLib1 connection will be severed.
The other main change is the support for C code generation with
uninterpreted functions enabling users to interface with external
C functions defined elsewhere. See below for details.
Other changes:
Code:
* Change getModel, so it returns an Either value to indicate
something went wrong; instead of throwing an error
* Add support for computing CRCs directly (without needing
polynomial division).
Code generation:
* Add "cgGenerateDriver" function, which can be used to turn
on/off driver program generation. Default is to generate
a driver. (Issue "cgGenerateDriver False" to skip the driver.)
For a library, a driver will be generated if any of the
constituent parts has a driver. Otherwise it will be skipped.
* Fix a bug in C code generation where "Not" over booleans were
incorrectly getting translated due to need for masking.
* Add support for compilation with uninterpreted functions. Users
can now specify the corresponding C code and SBV will simply
call the "native" functions instead of generating it. This
enables interfacing with other C programs. See the functions:
cgAddPrototype, cgAddDecl, and cgAddLDFlags.
Examples:
* Add CRC polynomial generation example via existentials
* Add USB CRC code generation example, both via polynomials and using the internal CRC functionality
### Version 0.9.21, 2011-08-05
Code generation:
* Allow for inclusion of user makefiles
* Allow for CCFLAGS to be set by the user
* Other minor clean-up
### Version 0.9.20, 2011-06-05
Regression on 0.9.19; add missing file to cabal
### Version 0.9.19, 2011-06-05
* Add SignCast class for conversion between signed/unsigned
quantities for same-sized bit-vectors
* Add full-binary trees that can be indexed symbolically (STree). The
advantage of this type is that the reads and writes take
logarithmic time. Suitable for implementing faster symbolic look-up.
* Expose HasSignAndSize class through Data.SBV.Internals
* Many minor improvements, file re-orgs
Examples:
* Add sentence-counting example
* Add an implementation of RC4
### Version 0.9.18, 2011-04-07
Code:
* Re-engineer code-generation, and compilation to C.
In particular, allow arrays of inputs to be specified,
both as function arguments and output reference values.
* Add support for generation of generation of C-libraries,
allowing code generation for a set of functions that
work together.
Examples:
* Update code-generation examples to use the new API.
* Include a library-generation example for doing 128-bit
AES encryption
### Version 0.9.17, 2011-03-29
Code:
* Simplify and reorganize the test suite
Examples:
* Improve AES decryption example, by using
table-lookups in InvMixColumns.
### Version 0.9.16, 2011-03-28
Code:
* Further optimizations on Bits instance of SBV
Examples:
* Add AES algorithm as an example, showing how
encryption algorithms are particularly suitable
for use with the code-generator
### Version 0.9.15, 2011-03-24
Bug fixes:
* Fix rotateL/rotateR instances on concrete
words. Previous versions was bogus since
it relied on the Integer instance, which
does the wrong thing after normalization.
* Fix conversion of signed numbers from bits,
previous version did not handle twos
complement layout correctly
Testing:
* Add a sleuth of concrete test cases on
arithmetic to catch bugs. (There are many
of them, ~30K, but they run quickly.)
### Version 0.9.14, 2011-03-19
- Reimplement sharing using Stable names, inspired
by the Data.Reify techniques. This avoids tricks
with unsafe memory stashing, and hence is safe.
Thus, issues with respect to CAFs are now resolved.
### Version 0.9.13, 2011-03-16
Bug fixes:
* Make sure SBool short-cut evaluations are done
as early as possible, as these help with coding
recursion-depth based algorithms, when dealing
with symbolic termination issues.
Examples:
* Add fibonacci code-generation example, original
code by Lee Pike.
* Add a GCD code-generation/verification example
### Version 0.9.12, 2011-03-10
New features:
* Add support for compilation to C
* Add a mechanism for offline saving of SMT-Lib files
Bug fixes:
* Output naming bug, reported by Josef Svenningsson
* Specification bug in Legatos multipler example
### Version 0.9.11, 2011-02-16
* Make ghc-7.0 happy, minor re-org on the cabal file/Setup.hs
### Version 0.9.10, 2011-02-15
* Integrate commits from Iavor: Generalize SBVs to keep
track the integer directly without resorting to different
leaf types
* Remove the unnecessary CLC instruction from the Legato example
* More tests
### Version 0.9.9, 2011-01-23
* Support for user-defined SMT-Lib axioms to be
specified for uninterpreted constants/functions
* Move to using doctest style inline tests
### Version 0.9.8, 2011-01-22
* Better support for uninterpreted-functions
* Support counter-examples with SArrays
* Ladner-Fischer scheme example
* Documentation updates
### Version 0.9.7, 2011-01-18
* First stable public hackage release
### Versions 0.0.0 - 0.9.6, Mid 2010 through early 2011
* Basic infrastructure, design exploration