When Emacs is started up, it normally runs an file called
.emacs located in your home directory. This file should
contain all of your personal customisations written as a series of
Elisp commands. In order to install the Haskell mode, you have to
tell Emacs where to find it. This is done by adding some commands to
the init file.
Download the and unpack the basic mode and modules into a
suitable directory, e.g. ~/lib/emacs where ~
stands for your home directory.
Assuming you have placed the basic mode
haskell-mode.el and the modules you want to use in the
directory ~/lib/emacs, add the following commands to your
init file (~/.emacs):
(setq load-path (cons "~/lib/emacs" load-path))
(setq auto-mode-alist
(append auto-mode-alist
'(("\\.[hg]s$" . haskell-mode)
("\\.hi$" . haskell-mode)
("\\.l[hg]s$" . literate-haskell-mode))))
(autoload 'haskell-mode "haskell-mode"
"Major mode for editing Haskell scripts." t)
(autoload 'literate-haskell-mode "haskell-mode"
"Major mode for editing literate Haskell scripts." t)
adding the following lines according to which modules you want to use:
(add-hook 'haskell-mode-hook 'turn-on-haskell-font-lock) (add-hook 'haskell-mode-hook 'turn-on-haskell-decl-scan) (add-hook 'haskell-mode-hook 'turn-on-haskell-doc-mode) (add-hook 'haskell-mode-hook 'turn-on-haskell-indent) (add-hook 'haskell-mode-hook 'turn-on-haskell-simple-indent) (add-hook 'haskell-mode-hook 'turn-on-haskell-hugs)
Note that the two indentation modules are mutually exclusive - add
at most one. You can download the above code.
Note that the line of code for simple indentation is commented out
(using a preceeding ;) in preference for the more
advanced indentation module. Installation is now complete!
For those interested, each command above shall now be explained.
We must ensure that the directory containing
haskell-mode.el is on the load-path of
Emacs. You can examine the value of the load-path by
typing C-h v load-path in an Emacs session. Supposing
that you've placed haskell-mode.el in the directory
~/lib/emacs, if this directory is not on the
load-path we add it with:
(setq load-path (cons "~/lib/emacs" load-path))
The function setq sets the value of a variable, and the
function cons takes an element and a list and creates a
new list with the former as head and the latter as tail, as in
Haskell.
It is possible (and desirable) for Emacs to enter a specific
mode according to the name of the file being edited/visited. The
variable auto-mode-alist tells Emacs what mode to run
according to which regular expression matches the filename. We wish
to run the Haskell mode on all files ending in .hs,
.hi (interface file) and .gs (Gofer file),
and to run the Haskell mode for literate scripts on all files ending
in .lhs and .lgs. To do this, we need to
add pairs of the form (regexp
. mode-function). We use the function
append to append a list of three such pairs to the end of
the value of auto-mode-alist. A list in Elisp is written
within round parantheses with elements separated by whitespace. A
list is treated as a function application unless it is quoted with
', which is what we do.
In order for Emacs to know where to find the definition of our
mode functions, haskell-mode and
literate-haskell-mode, we must use the function
autoload. Both mode functions can be found in the file
haskell-mode.el which was downloaded in the first
installation step (the .el extension is left off and
assumed by Emacs). As we have already ensured that this file is on
the load-path we need only give the filename and not the
directory. Its use is quite straightforward but for further
information, see its documentation by entering C-h f
autoload in an Emacs session.
Each function turn-on-haskell-module
turns on the corresponding module. Adding such a function as a hook
to the Haskell mode will turn on that module when the mode is used.
Note that each of these modules may slow down Emacs, especially for
large files.
Most customisations are on the functionality of a particular module. See the documentation of that module for information on its customisation.
Any problems, do mail and we will try our best to help you!