22.2.8 Generic Modes

Generic modes are simple major modes with basic support for comment syntax and Font Lock mode. To define a generic mode, use the macro define-generic-mode. See the file generic-x.el for some examples of the use of define-generic-mode.

Macro: define-generic-mode mode comment-list keyword-list font-lock-list auto-mode-list function-list &optional docstring

This macro defines a generic mode command named mode (a symbol, not quoted). The optional argument docstring is the documentation for the mode command. If you do not supply it, define-generic-mode generates one by default.

The argument comment-list is a list in which each element is either a character, a string of one or two characters, or a cons cell. A character or a string is set up in the mode’s syntax table as a “comment starter”. If the entry is a cons cell, the CAR is set up as a “comment starter” and the CDR as a “comment ender”. (Use nil for the latter if you want comments to end at the end of the line.) Note that the syntax table mechanism has limitations about what comment starters and enders are actually possible. See Syntax Tables.

The argument keyword-list is a list of keywords to highlight with font-lock-keyword-face. Each keyword should be a string. Meanwhile, font-lock-list is a list of additional expressions to highlight. Each element of this list should have the same form as an element of font-lock-keywords. See Search-based Fontification.

The argument auto-mode-list is a list of regular expressions to add to the variable auto-mode-alist. They are added by the execution of the define-generic-mode form, not by expanding the macro call.

Finally, function-list is a list of functions for the mode command to call for additional setup. It calls these functions just before it runs the mode hook variable mode-hook.