{\tt ghc-mod} is a backend command to enrich Haskell programming on editors including Emacs, Vim and Sublime. The ghc-mod package on Hackage includes the {\tt ghc-mod} command and Emacs front-end.
\item[Completion] You can complete a name of keyword, module, class, function, types, language extensions, etc.
\item[Code template] You can insert a code template according to the position of the cursor. For instance, ``module Foo where'' is inserted in the beginning of a buffer.
\item[Syntax check] Code lines with error messages are automatically highlighted thanks to flymake. You can display the error message of the current line in another window. {\tt hlint}%\cref{hlint}
can be used instead of GHC to check Haskell syntax.
\item[Document browsing] You can browse the module document of the current line either locally or on Hackage.
\item[Expression type] You can display the type/information of the expression on the cursor.