Re: return of replace-match

[Alex Kost]

Phillip Lord (2014-03-04 18:42 +0400) wrote:

> I've been trying out "replace-match". The elisp manual says....
>
>  -- Function: replace-match replacement &optional fixedcase literal
>           string subexp
>      This function performs a replacement operation on a buffer or
>      string.
>
>      If you did the last search in a buffer, you should omit the STRING
>      argument or specify `nil' for it, and make sure that the current
>      buffer is the one in which you performed the last search.  Then
>      this function edits the buffer, replacing the matched text with
>      REPLACEMENT.  It leaves point at the end of the replacement text,
>      and returns `t'.
>
>
> However, if I eval the progn below (with bob where it says)
>
> (progn
>   (re-search-forward "bob")
>   (replace-match "fred"))
>
> bob
>
>
>
> point gets moved to the end of "bob" (now "fred") but "nil" is returned.
>
>
> The docstring doesn't say anything at all about return types (unless
> operating over a string.
>
> Am I doing something wrong?
>
> Phil

It looks correct to me.  When the docstring tells nothing about the
returning value, it may be anything and you shouldn't rely on it.

`replace-match' returns a string when you operate on a string, not a
text in a buffer.