Replace some things after point matching REGEXP with TO-STRING.
As each match is found, the user must type a character saying
what to do with it. For directions, type C-h at that time.
In Transient Mark mode, if the mark is active, operate on the contents
of the region. Otherwise, operate from point to the end of the buffer.
Use M-n to pull the last incremental search regexp to the minibuffer
that reads REGEXP, or invoke replacements from
incremental search with a key sequence like `C-M-s C-M-s C-M-%'
to use its current search regexp as the regexp to replace.
Matching is independent of case if `case-fold-search' is non-nil and
REGEXP has no uppercase letters. Replacement transfers the case
pattern of the old text to the new text, if `case-replace' and
`case-fold-search' are non-nil and REGEXP has no uppercase letters.
(Transferring the case pattern means that if the old text matched is
all caps, or capitalized, then its replacement is upcased or
If `replace-regexp-lax-whitespace' is non-nil, a space or spaces in the regexp
to be replaced will match a sequence of whitespace chars defined by the
regexp in `search-whitespace-regexp'.
Third arg DELIMITED (prefix arg if interactive), if non-nil, means replace
only matches surrounded by word boundaries.
Fourth and fifth arg START and END specify the region to operate on.
In TO-STRING, `\&' stands for whatever matched the whole of REGEXP,
and `\N' (where N is a digit) stands for
whatever what matched the Nth `\(...\)' in REGEXP.
`\?' lets you edit the replacement text in the minibuffer
at the given position for each replacement.
In interactive calls, the replacement text can contain `\,'
followed by a Lisp expression. Each
replacement evaluates that expression to compute the replacement
string. Inside of that expression, `\&' is a string denoting the
whole match as a string, `\N' for a partial match, `\#&' and `\#N'
for the whole or a partial match converted to a number with
`string-to-number', and `\#' itself for the number of replacements
done so far (starting with zero).
If the replacement expression is a symbol, write a space after it
to terminate it. One space there, if any, will be discarded. When using those Lisp features interactively in the replacement text, TO-STRING is actually made a list instead of a string. Use C-x M-: after this command for details.