[Haskell-cafe] symbolic evaluator for Haskell?

[wren ng thornton]

Tim Newsham wrote:
> Is there a symbolic evaluator for Haskell that will perform all
> applications except on specified functions?  Ie. I would love
> something that would take
> 
>     foldr (+) (6 `div` 5) [1,2,3*4]
> 
> and "(+) (*)" and return
> 
>    1 + (2 + (3*4 + 1))
> 
> by performing all the applications except for (+) and (*).
> (Something that supports ghc extensions is preferred :)

Lambdabot (on #haskell) has something similar using a type, Expr, to 
overload certain names, e.g.

     koninkje   > foldr f z [1..5]
     lambdabot  f 1 (f 2 (f 3 (f 4 (f 5 z))))

It's a complete hack and isn't as sophisticated as what you're after, 
but it could serve as a basis for implementation ideas.

-- 
Live well,
~wren