Toggle parser features (Semantic mode).
With a prefix argument ARG, enable Semantic mode if ARG is
positive, and disable it otherwise. If called from Lisp, enable
Semantic mode if ARG is omitted or nil.
In Semantic mode, Emacs parses the buffers you visit for their
semantic content. This information is used by a variety of
auxiliary minor modes, listed in `semantic-default-submodes';
all the minor modes in this list are also enabled when you enable
Semantic mode.
Uses keymap `semantic-mode-map', which is not currently defined.
(fn &optional ARG)
Non-nil if Semantic mode is enabled.
See the command `semantic-mode' for a description of this minor mode.
Setting this variable directly does not take effect;
either customize it (see the info node `Easy Customization')
or call the function `semantic-mode'.