Syntactic fontification uses a syntax table (see Syntax Tables) to
find and highlight syntactically relevant text. If enabled, it runs
prior to search-based fontification. The variable
font-lock-syntactic-face-function, documented below, determines
which syntactic constructs to highlight. There are several variables
that affect syntactic fontification; you should set them by means of
font-lock-defaults (see Font Lock Basics).
Whenever Font Lock mode performs syntactic fontification on a stretch
of text, it first calls the function specified by
syntax-propertize-function. Major modes can use this to apply
syntax-table text properties to override the buffer’s syntax
table in special cases. See Syntax Properties.
If the value of this variable is non-
nil, Font Lock does not do
syntactic fontification, only search-based fontification based on
font-lock-keywords. It is normally set by Font Lock mode based
on the keywords-only element in
This variable holds the syntax table to use for fontification of
comments and strings. It is normally set by Font Lock mode based on the
syntax-alist element in
font-lock-defaults. If this value
nil, syntactic fontification uses the buffer’s syntax table
(the value returned by the function
syntax-table; see Syntax Table Functions).
If this variable is non-
nil, it should be a function to move
point back to a position that is syntactically at “top level” and
outside of strings or comments. The value is normally set through an
other-vars element in
font-lock-defaults. If it is
nil, Font Lock uses
syntax-begin-function to move back
outside of any comment, string, or sexp (see Position Parse).
This variable is semi-obsolete; we usually recommend setting
syntax-begin-function instead. One of its uses is to tune the
behavior of syntactic fontification, e.g., to ensure that different
kinds of strings or comments are highlighted differently.
The specified function is called with no arguments. It should leave
point at the beginning of any enclosing syntactic block. Typical values
beginning-of-line (used when the start of the line is known
to be outside a syntactic block), or
programming modes, or
backward-paragraph for textual modes.
If this variable is non-
nil, it should be a function to determine
which face to use for a given syntactic element (a string or a comment).
The value is normally set through an other-vars element in
The function is called with one argument, the parse state at point
parse-partial-sexp, and should return a face. The
default value returns
font-lock-comment-face for comments and
font-lock-string-face for strings (see Faces for Font Lock).