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37.12 Faces

A face is a collection of graphical attributes for displaying text: font, foreground color, background color, optional underlining, etc. Faces control how Emacs displays text in buffers, as well as other parts of the frame such as the mode line.

One way to represent a face is as a property list of attributes, like (:foreground "red" :weight bold). Such a list is called an anonymous face. For example, you can assign an anonymous face as the value of the face text property, and Emacs will display the underlying text with the specified attributes. See Special Properties.

More commonly, a face is referred to via a face name: a Lisp symbol associated with a set of face attributes19. Named faces are defined using the defface macro (see Defining Faces). Emacs comes with several standard named faces (see Basic Faces).

Many parts of Emacs required named faces, and do not accept anonymous faces. These include the functions documented in Attribute Functions, and the variable font-lock-keywords (see Search-based Fontification). Unless otherwise stated, we will use the term face to refer only to named faces.

Function: facep object

This function returns a non-nil value if object is a named face: a Lisp symbol or string which serves as a face name. Otherwise, it returns nil.


Footnotes

(19)

For backward compatibility, you can also use a string to specify a face name; that is equivalent to a Lisp symbol with the same name.

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