View Reduction Steps in Haskell

Question

I was wondering if there is anyway to view the reduction steps in haskell, i.e trace the recursive function calls made, for e.g chez scheme provides us with trace-lambda, is there an equivalent form in Haskell, and how to use it?

Thanks, Shiv

Answer 1

There's a reduction count in hugs, if that helps? Alternatively, could you use something like the hugs hood to wrap your code, to get more detail around what it's doing at each step?

Answer 2

Nothing of the kind is built into the Haskell standard.

I would hope that the Helium graphical interpreter would offer something like this, but the web page is silent on the topic.

Answer 3

A partial solution is to use vacuum to visualize data structures.

I've seen some gif animations of fold, scan and others, but I can't find them at the moment. I think Cale Gibbard made the animations.