Toggle syntax highlighting in this buffer (Font Lock mode).
With a prefix argument ARG, enable Font Lock mode if ARG is
positive, and disable it otherwise. If called from Lisp, enable
the mode if ARG is omitted or nil.
When Font Lock mode is enabled, text is fontified as you type it:
- Comments are displayed in `font-lock-comment-face';
- Strings are displayed in `font-lock-string-face';
- Certain other expressions are displayed in other faces according to the
value of the variable `font-lock-keywords'.
To customize the faces (colors, fonts, etc.) used by Font Lock for
fontifying different parts of buffer text, use M-x customize-face.
You can enable Font Lock mode in any major mode automatically by turning on in
the major mode's hook. For example, put in your ~/.emacs:
(add-hook 'c-mode-hook 'turn-on-font-lock)
Alternatively, you can use Global Font Lock mode to automagically turn on Font
Lock mode in buffers whose major mode supports it and whose major mode is one
of `font-lock-global-modes'. For example, put in your ~/.emacs:
(global-font-lock-mode t)
Where major modes support different levels of fontification, you can use
the variable `font-lock-maximum-decoration' to specify which level you
generally prefer. When you turn Font Lock mode on/off the buffer is
fontified/defontified, though fontification occurs only if the buffer is
less than `font-lock-maximum-size'.
To add your own highlighting for some major mode, and modify the highlighting
selected automatically via the variable `font-lock-maximum-decoration', you can
use `font-lock-add-keywords'.
To fontify a buffer, without turning on Font Lock mode and regardless of buffer
size, you can use M-x font-lock-fontify-buffer.
To fontify a block (the function or paragraph containing point, or a number of
lines around point), perhaps because modification on the current line caused
syntactic change on other lines, you can use M-o M-o.
You can set your own default settings for some mode, by setting a
buffer local value for `font-lock-defaults', via its mode hook.
The above is the default behavior of `font-lock-mode'; you may specify
your own function which is called when `font-lock-mode' is toggled via
`font-lock-function'.
Non-nil if Font-Lock mode is enabled.
Use the command `font-lock-mode' to change this variable.