sbv-0.9.24: RELEASENOTES
Hackage: <http://hackage.haskell.org/package/sbv>
GitHub: <http://github.com/LeventErkok/sbv>
======================================================================
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's 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's 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 Integer's 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's 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'll 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
Code:
* 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 two's
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 Legato's 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 SBV's 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 SArray's
* 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