[Haskell-cafe] symbolic evaluator for Haskell?

Tim Newsham newsham at lava.net
Wed Mar 18 13:00:16 EDT 2009

> 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.

I'm aware of the Expr stuff in lambdabot and elsewhere.  This is not
quite what I need, perhaps I should have picked an example that
doesn't almost-work with Expr.  I need something that will symbolically
evaluate a complex non-numeric expression that makes use of GADTs.

I'm thinking it might not be too hard to implement using TH, but haven't
tried yet...  (though not sure if TH supports GADTs).

> Live well,
> ~wren

Tim Newsham

More information about the Haskell-Cafe mailing list