Installation

See The Emacs Interface, for more information about installing the Emacs interface.

There are some differences between GNU Emacs and XEmacs. This will be indicated with Emacs-Lisp comments in the examples.

Customizing Emacs

Version 20 of GNU Emacs and XEmacs introduced a new method for editing and storing user settings. This feature is available from the menu bar as Customize and particular Emacs variables can be customized with M-x customize-variable. Using Customize is the preferred way to modify the settings for emacs and the appropriate customize commands will be indicated below, sometimes together with the old method of directly setting Emacs variables.

Enabling Emacs Support for SICStus

Assuming the Emacs interface for SICStus Prolog has been installed in the default location, inserting the following lines in your ~/.emacs will make Emacs use this mode automatically when editing files with a .pl extension:

     (setq load-path
        (cons (expand-file-name "/usr/local/lib/sicstus-3.9.1/emacs")
              load-path))
     (autoload 'run-prolog "prolog" "Start a Prolog sub-process." t)
     (autoload 'prolog-mode "prolog" "Major mode for editing Prolog programs." t)
     (setq prolog-use-sicstus-sd t)
     (setq auto-mode-alist (cons '("\\.pl$" . prolog-mode) auto-mode-alist))
     

where the path in the first line is the file system path to prolog.el (the generic Prolog mode) and sicstus-support.el (SICStus specific code). For example, ~/emacs means that the file is in the user's home directory, in directory emacs. Windows paths can be written like C:/Program Files/SICStus Prolog 3.9.1/emacs.

The last line above makes sure that files ending with .pl are assumed to be Prolog files and not Perl, which is the default Emacs setting. If this is undesirable, remove that line. It is then necessary for the user to manually switch to prolog mode by typing M-x prolog-mode after opening a prolog file, for an alternative approach, see Mode Line.

If the shell command sicstus is not available in the default path, then it is necessary to set the value of the environment variable EPROLOG to a shell command to invoke SICStus Prolog. This is an example for C Shell:

     setenv EPROLOG /usr/local/bin/sicstus
     

Enabling Emacs Support for SICStus Documentation

It is possible to look up the documentation for any built in or library predicate from within Emacs (using C-c ? or the menu). For this to work Emacs must be told about the location of the info-files that make up the documentation.

The default location for the info-files are <prefix>/lib/sicstus-3.9.1/doc/info/ on UNIX platforms and C:/Program Files/SICStus Prolog 3.9.1/doc/info/ on Windows.

Add the following to your ~/.emacs file, assuming INFO is the path to the info files, e.g. C:/Program Files/SICStus Prolog 3.9.1/doc/info/

     (setq Info-default-directory-list
        (append Info-default-directory-list '("INFO")))
     

     (setq Info-directory-list
        (append Info-directory-list '("INFO")))
     

for XEmacs. You can also use M-x customize-group <RET> info <RET> if your Emacs is new enough. You may have to quit and restart Emacs for these changes to take effect.