Eev and Haskell
I am using a GHC installed with GHCup (notes),
One thing that I found very annoying about Haskell is that after installing a package with cabal-install I had to use commands like this
to get information on an installed package; I don't know how to set
a default value for "
it displays a temporary buffer like the one at the upper right in the screenshot below (click to enlarge it!), that contains several elisp hyperlinks that invoke eev-cabal with different arguments,
After those hyperlinks it shows an eepitch block for installing that package, and a link like this -
that only works correctly on installed packages, and that displays a temporary buffer like the one at the lower right part of the screenshot, that unpacks the source code of that package into a directory with a short name, and produces a code-c-d for it. The code in Lisp for find-cabal-links and find-cabal-unpack is quite simple, but I was only able to write eev-cabal after getting a lot of help in the #haskell IRC channel. =/
Here is another 5-minute hack that I am using a lot: find-ghc-links. When I type `M-x find-ghc-links' or `M-x ghl' it displays a temporary buffer like this (click to enlarge!),
with some useful links on the word around point. It works for both functions and names of modules - some of the links are only meaningful when the argument is the name of a function, and some only when it is the name of a module.
See also: http://angg.twu.net/HASKELL/.