Emacs/Project navigation
Emacs tags/hasktags
Get hasktags
ETAGS allows jumping to the definition of names at the point via M-.
. To generate tags (a TAGS file) for a project, you need hasktags.
$ cabal install hasktags
Calling directly
Run M-x haskell-process-generate-tags
to generate the TAGS file of the current session directory.
You can now use M-.
on a name in a Haskell buffer which will jump directly to its definition. You can also now use it for autocompletion.
On save
You just need to enable tags generation on save:
(custom-set-variables '(haskell-tags-on-save t))
or
(setq haskell-tags-on-save t)
or just M-x customize-group haskell
and it's in there.
Speedbar
Emacs has a SpeedBar which works quite nice together with haskell-mode and also detects syntactic elements such as variables, imports, instances, classes.
Just add
(require 'speedbar)
(speedbar-add-supported-extension ".hs")
to your .emacs file and fire up speedbar with
M-x speedbar
.