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29.2.2 Motion by Words

The functions for parsing words described below use the syntax table and char-script-table to decide whether a given character is part of a word. See Syntax Tables, and see Character Properties.

— Command: forward-word &optional count

This function moves point forward count words (or backward if count is negative). If count is omitted or nil, it defaults to 1. In an interactive call, count is specified by the numeric prefix argument.

“Moving one word” means moving until point crosses a word-constituent character, which indicates the beginning of a word, and then continue moving until the word ends. By default, characters that begin and end words, known as word boundaries, are defined by the current buffer's syntax table (see Syntax Class Table), but modes can override that by setting up a suitable find-word-boundary-function-table, described below. Characters that belong to different scripts (as defined by char-syntax-table), also define a word boundary (see Character Properties). In any case, this function cannot move point past the boundary of the accessible portion of the buffer, or across a field boundary (see Fields). The most common case of a field boundary is the end of the prompt in the minibuffer.

If it is possible to move count words, without being stopped prematurely by the buffer boundary or a field boundary, the value is t. Otherwise, the return value is nil and point stops at the buffer boundary or field boundary.

If inhibit-field-text-motion is non-nil, this function ignores field boundaries.

— Command: backward-word &optional count

This function is just like forward-word, except that it moves backward until encountering the front of a word, rather than forward.

— User Option: words-include-escapes

This variable affects the behavior of forward-word and backward-word, and everything that uses them. If it is non-nil, then characters in the escape and character-quote syntax classes count as part of words. Otherwise, they do not.

— Variable: inhibit-field-text-motion

If this variable is non-nil, certain motion functions including forward-word, forward-sentence, and forward-paragraph ignore field boundaries.

— Variable: find-word-boundary-function-table

This variable affects the behavior of forward-word and backward-word, and everything that uses them. Its value is a char-table (see Char-Tables) of functions to search for word boundaries. If a character has a non-nil entry in this table, then when a word starts or ends with that character, the corresponding function will be called with 2 arguments: pos and limit. The function should return the position of the other word boundary. Specifically, if pos is smaller than limit, then pos is at the beginning of a word, and the function should return the position after the last character of the word; otherwise, pos is at the last character of a word, and the function should return the position of that word's first character.

— Function: forward-word-strictly &optional count

This function is like forward-word, but it is not affected by find-word-boundary-function-table. Lisp programs that should not change behavior when word movement is modified by modes which set that table, such as subword-mode, should use this function instead of forward-word.

— Function: backward-word-strictly &optional count

This function is like backward-word, but it is not affected by find-word-boundary-function-table. Like with forward-word-strictly, use this function instead of backward-word when movement by words should only consider syntax tables.