After spending about the last 3 months replying to most people's Hoogle comments with "that will be fixed in Hoogle 4", its about time I actually implement Hoogle 4. Just to give people an idea of where I'm going, I thought I'd summarise what Hoogle 4 means to me :)
First off, I abandoned .ths after talking with Niklas who does Haskell-source-exts and HSP, and will be using his stuff. Its got advantages of tag safety and a better syntax, lacks a few bits, but being written by someone else saves me a bit of work. Its also well supported, something thats essential!
Anyway, the plans for Hoogle 4 fall into a few areas:
No bugs: type classes, type aliases, higher kinded type classes - all these things confuse Hoogle. Either they are bugs, or they come close enough to count as them. These will all be fixed.
Help the user: searching for ThreadID doesn't work (its ThreadId), searching for Just a doesn't work, searching for Maybe -> Int doesn't work, all just fail silently. I want to tell people when they are searching a bit dubiously and fix it for them.
Do what users keep asking for: often users do searches for multiple words, "map concat", this currently gives them very confusing results (the type "m a" is equivalent).
Be a database: I want to give more database like features, lookup Just will give you the functions that use it.
Faster: I want to make text searching 100's of times faster, which isn't so the results come back faster but so that...
Packages: I want to be able to search packages other than the default ones, such as Gtk2hs (which you can already Hoogle search), and lots lots more. Which requires a speed boost.
AJAX: I have a few good AJAX ideas for making searching just a little bit quicker.
Lots to do, and will probably be an entire rewrite (again...), but this is hopefully going to be the version that sticks arond for a very long time and comes out of Beta.