Thanks for the suggestion Don,
I started the wiki page at http://haskell.org/haskellwiki/Debugging
On 06/09/06, Donald Bruce Stewart
mnislaih:
Hi Tamas
There are several ways to debug a Haskell program.
The most advanced ones are based in offline analysis of traces, I think Hat [1] is the most up-to-date tool for this. There is a Windows port of Hat at [5].
Another approach is to simply use Debug.Trace. A more powerful alternative for this approach is Hood [2]. Even if it hasn't been updated in some time, Hood works perfectly with the current ghc distribution. Even more, Hugs has it already integrated [3]. You can simply import Observe and use observations directly in your program. For instance:
import Observe
f' = observe "f" f f a b = ....
And then in hugs the expression:
f' 1 2
would output what you want.
Finally, the GHCi debugger project [4] aims to bring dynamic breakpoints and intermediate values observation to GHCi in a near future. Right now the tool is only available from the site as a modified version of GHC, so unfortunately you will have to compile it yourself if you want to try it.
Pepe, would you like to put up a page on the haskell.org wiki about debugging in Haskell? You could use the above mail as a start :)
-- Don