Elisp: Syntax Table

What is Syntax Table

Syntax table is a lookup table. It store info about character's class, such as whitespace, word, symbol (programing language identifier), punctuations, bracket, etc.

Where is Syntax Table Used

Syntax table is heavily used in emacs. For example,

• Most cursor movement commands rely on syntax table. For example, when you forward-word 【Alt+f】, emacs moves cursor until it reaches a character that's not in the “word” class.
• Syntax coloring of strings and comments rely on syntax table. 〔see Elisp: Syntax Color Comments〕
• Lisp mode's parenthesis navigation depends on syntax table. 〔see Emacs: Navigate Lisp Code as Tree〕

Syntax Table is Local to Buffer

Each buffer has its own syntax table.

Typically, when a Major Mode is activated, it changes the current buffer's syntax table.

Standard Syntax Table

• Standard syntax table is the syntax table used by Fundamental Mode.
• Every syntax table is derived from standard syntax table.

The function standard-syntax-table returns the standard syntax table.

Syntax Table Inheritance

Emacs syntax table has inheritance. That is, each syntax table you create inherits a parent syntax table. You do not need to set every character's syntax class. When a syntax table does not have entry for a character, it uses the parent table.

Syntax table commands have optional parameter for a table name of a parent table. When not specified, the parent syntax table is the standard syntax table.

• Syntax Table Functions (ELISP Manual)

Create a Syntax Table

• Elisp: Create Syntax Table

Reference

• Syntax Tables (ELISP Manual)