https://github.com/manzyuk/ghci-completion.git
git clone 'git://github.com/manzyuk/ghci-completion.git'
To support completion for GHCi commands (like :load, :module,
:set etc.) in inferior-haskell buffers.
To turn on GHCi commands completion in inferior-haskell buffers, add
this to .emacs:
(add-hook 'inferior-haskell-mode-hook 'turn-on-ghci-completion)
Otherwise, call turn-on-ghci-completion.
You may also want to set ghci-completion-ghc-pkg-additional-args to
the list of additional argument to supply to ghc-pkg. For example,
this variable can be used to specify which database (user or global)
or which package config file to use.
This package is developed for Emacs 24 and it probably only works
with Emacs 24. In particular, we rely on lexical bindings, which
have been introduced in Emacs 24, and on pcomplete, which is
effectively broken in 23.2.
Only the following commands are supported: :add, :browse[!],
:cd, :edit, :load, :module, :set, :unset, :show. It
would be nice to have shell completion for :!, for example.
The starred versions of the commands :add, :browse[!], :load,
and :module are not supported, partly because I don't use them,
and partly because, for example, :module offers completion only on
the exposed modules in registered packages in both the global and
user databases, and for these :module *<mod> is meaningless.
:set and :unset support only a subset of all GHC flags: language
extensions, warnings, and debugging options. Adding completion for
other flags is trivial. It would be nice, however, to be able to
generate the list of all GHC flags programmatically.