— Function: perform-replace from-string replacements query-flag regexp-flag delimited-flag &optional repeat-count map

This function is the guts of query-replace and related commands. It searches for occurrences of from-string and replaces some or all of them. If query-flag is nil, it replaces all occurrences; otherwise, it asks the user what to do about each one.

If regexp-flag is non-nil, then from-string is considered a regular expression; otherwise, it must match literally. If delimited-flag is non-nil, then only replacements surrounded by word boundaries are considered.

The argument replacements specifies what to replace occurrences with. If it is a string, that string is used. It can also be a list of strings, to be used in cyclic order.

If repeat-count is non-nil, it should be an integer. Then it specifies how many times to use each of the strings in the replacements list before advancing cyclicly to the next one.

Normally, the keymap query-replace-map defines the possible user responses for queries. The argument map, if non-nil, is a keymap to use instead of query-replace-map.

— Variable: query-replace-map

This variable holds a special keymap that defines the valid user responses for query-replace and related functions, as well as y-or-n-p and map-y-or-n-p. It is unusual in two ways:

• The “key bindings” are not commands, just symbols that are meaningful to the functions that use this map.
• Prefix keys are not supported; each key binding must be for a single event key sequence. This is because the functions don't use read key sequence to get the input; instead, they read a single event and look it up “by hand.”