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hermit-0.1.8.0: Haskell Equational Reasoning Model-to-Implementation Tunnel

The hermit package

HERMIT uses Haskell to express semi-formal models, efficient implementations, and provide a bridging DSL to describe via stepwise refinement the connection between these models and implementations. The key transformation in the bridging DSL is the worker/wrapper transformation.

This is a pre-alpha `please give feedback' release. Shortcomings/gotchas include:

• Command line completion is ad hoc at the moment.

• log command prints linearly, even if command history is a tree.

• The fold rewrite can only fold syntactically alpha-equivalent (up to parameters of the function you are folding) expressions.

• RULES have issues with forall types.

• Different core comes out depending on whether you ascribe explicit type signatures.

• A number of rewrites don't enforce preconditions. ex: cast elimination always works, even if the cast is necessary

Examples can be found in the examples sub-directory.

$ cd examples/reverse

Example of running a script.

$ hermit Reverse.hs Reverse.hss resume
[starting HERMIT v0.1.8.0 on Reverse.hs]
% ghc Reverse.hs -fforce-recomp -O2 -dcore-lint -fexpose-all-unfoldings -fsimple-list-literals -fplugin=HERMIT -fplugin-opt=HERMIT:Main:Reverse.hss -fplugin-opt=HERMIT:Main:resume
[1 of 2] Compiling HList            ( HList.hs, HList.o )
Loading package ghc-prim ... linking ... done.
...
Loading package hermit-0.1.8.0 ... linking ... done.
[2 of 2] Compiling Main             ( Reverse.hs, Reverse.o )
Linking Reverse ...
$ ./Reverse
....

Example of interactive use.

$ hermit Reverse.hs
[starting HERMIT v0.1.8.0 on Reverse.hs]
% ghc Reverse.hs -fforce-recomp -O2 -dcore-lint -fexpose-all-unfoldings -fsimple-list-literals -fplugin=HERMIT -fplugin-opt=HERMIT:Main:
[1 of 2] Compiling HList            ( HList.hs, HList.o )
Loading package ghc-prim ... linking ... done.
...
Loading package hermit-0.1.8.0 ... linking ... done.
[2 of 2] Compiling Main             ( Reverse.hs, Reverse.o )
module main:Main where
  rev ∷ ∀ a . [a] -> [a]
  unwrap ∷ ∀ a . ([a] -> [a]) -> [a] -> H a
  wrap ∷ ∀ a . ([a] -> H a) -> [a] -> [a]
  main ∷ IO ()
  main ∷ IO ()
hermit<0>
...

To resume compilation, use resume.

...
hermit<0> resume
hermit<0> Linking Reverse ...
$

Properties

Modules

Downloads

• hermit-0.1.8.0.tar.gz (Cabal source package)
• package description (included in the package)

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