Haskell bindings to SymEngine
Clone or download
Pull request Compare This branch is 40 commits ahead, 2 commits behind symengine:master.
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.



Build Status Test Coverage Issue Count

Haskell bindings to SymEngine


Stack, a Haskell build tool

Stack is a Haskell build tool, which allows for cross-platform, reproducible builds.

The build toolchain of this project depends on stack, so please follow the installation instructions as outlined here

SymEngine, the library that this package provides a Haskell interface for

Please go through the SymEngine installation instructions, and make sure that the header files as well as the libraries

  • symengine
  • gmp
  • gmpxxx

Since these are hard dependencies for SymEngine-hs to build.

Compile SymEngine with the CMake flags


Getting started

To quickly build and check everything is working, run

stack build && stack test --test-arguments "--quickcheck-tests 2000" --verbose

All of the test cases should pass with SymEngine

Playing around in the interpreter

to launch a GHCi session, execute the interpreter with

stack ghci --ghci-options " -lstdc++ -lgmpxx -lgmp -lsymengine -L/usr/local/lib/"

Make sure that you have built symengine.so (NOTE: you _need the shared object, and not just the library), and have installed the shared object as well.

Once you are inside GHCi, you can execute basic functions such as basic_const_zero, basic_const_one, etc.

A typical interpreter session will look like this:

GHCi session with Symengine loaded

*Symengine Symengine> basic_const_zero
*Symengine Symengine> basic_const_zero
*Symengine Symengine> basic_const_one
*Symengine Symengine> basic_const_minus_one


clone Symengine, build it with the setting


this makes sure that dynamically linked libraries are being built, so we can link to them.

to test changes, use

stack test --force-dirty  --test-arguments "--quickcheck-tests 2000" --verbose
  • change `--quickcheck-tests" to some number (preferably > 100), since it generates those many instances to test on

  • the --force-dirty ensures that the library and the test builds are both rebuilt.


All code is released under the MIT License.

Things Learnt

  • you can use toEnum to convert from Int to the C<Int | Long | ..> variants of C types

  • API design - how to best handle exceptions?


  • if I create a lazy list of BasicSym, then what happens? it gets forced to evaluate when I pass it through something like densematrix_diag

  • densematrix_new_vec 2 3 [] crashes. We need to check for this in our code

  • What exactly does 'unsafePerformIO' do? why does unsafePerformIO on basicsym_new yield weird as hell errors?

  • take proper care of ref. transparency. eg: densematrix_set

  • Maybe allow GHC to tell about "typo errors" when looking for modules

  • merijn You'll want newPinnedByteArray# :: Int# -> State# s -> (#State# s, MutableByteArray# s#)

  • is the API Thread-safe?