Hoogle is a Haskell API search engine, which allows you to search the Haskell libraries on Stackage by either function name, or by approximate type signature.
Note: This version of hoogle is running using the packages available to Agora
Example searches:
pmap
Term s ((a :--> b) :--> list a :--> list b)
Term s (PValue _ a :--> PValue _ a)
ClosedTerm a -> Script
+liqwid-plutarch-extra pvalue
Enter your own search at the top of the page.
The Hoogle manual contains more details, including further details on search queries, how to install Hoogle as a command line application and how to integrate Hoogle with Firefox/Emacs/Vim etc.
I am very interested in any feedback you may have. Please email me, or add an entry to my bug tracker.