haskell-tab-indent-mode is a simple Emacs indentation minor mode for Haskell projects which require tabs for indentation and do not permit spaces (except for where clauses, as a special case). A prominent example of such a project is git-annex.

The user may use TAB to cycle between possible indentations.

Installation

You may copy haskell-tab-indent.el to somewhere in your load-path and simply

(autoload 'haskell-tab-indent-mode "haskell-tab-indent.el")

Or you may use git subtrees:

emacs-pkg-subtree add https://git.spwhitton.name/haskell-tab-indent 0.1.0

haskell-tab-indent is also available from MELPA (and MELPA Stable).

Usage

If you set indent-tabs-mode in the .dir-locals.el file for a project requiring tabs, you can use something like this in your init file to enable this mode for such projects, defaulting to the usual haskell-indentation-mode:

(add-hook 'haskell-mode-hook
            (lambda ()
              (add-hook 'hack-local-variables-hook
                        (lambda ()
                          (if indent-tabs-mode
                              (haskell-tab-indent-mode)
                            (haskell-indentation-mode)))
                        nil t))) ; local hook