This week I've been trying to get Hoogle 4 to the point where it can replace Hoogle 3. This is the final official week of Google Summer of Code, but I'm planning to continue hacking Hoogle next week, and then as time allows after that.
The priority this week was getting the documentation links working. The problem was not with Hoogle - displaying the links is trivial - but ensuring that Cabal + Haddock + Hoogle + random build scripts combine to generate the correct databases. This work involved lots of little changes in lots of places, but is now working properly. Included in this work is dependency tracking of packages (so that all packages using base know that String = [Char] etc), and merging multiple databases to create a single one.
After the Hoogle database was generated correctly, I started looking at using some of the additional information present. I have now added Haddock documentation inline in the search results. If the documentation is too long to fit comfortably, Hoogle uses AJAX wizzy-ness (or more accurately, DHTML) to allow the user to expand and show all the documentation. I suspect that this will eliminate many cases of the user actually following to the Haddock webpages. This feature is fairly new, and I have pushed it out because its useful - there are still many small improvements that need to be made.
This week I also spent some time attempting to generate documentation for all the Hackage libraries. I had some success, but the computer I am currently using is years old and lacks the necessary processing power. I will tackle this at some point in the future, once I have purchased a new machine (which should be quite soon).
With all these changes, I find Hoogle 4 to be significantly more usable than Hoogle 3. Please give it a try, and give feedback. At this point I'm particularly interested in any issues that would cause you to use Hoogle 3 instead of Hoogle 4.
Hoogle 3: http://haskell.org/hoogle
Hoogle 4: http://haskell.org/hoogle/beta
If there are no major issues, I will be replacing Hoogle 4 as the standard Hoogle sometime next week.
Next week: I will be no longer doing Google Summer of Code :-) I plan to refine some of the existing bits of Hoogle, and ensure that anything I haven't done is in a bug tracker for later.
User visible changes: The web search engine now gives Haddock links and displays Haddock documentation inline.