Re: string-match bug?

["Andreas Röhler" <andreas.roehler@easy-emacs.de>]

Matthew Dempsky wrote:
> On Mon, Dec 7, 2009 at 12:37 PM, Andreas Röhler
> <andreas.roehler@easy-emacs.de> wrote:
>> Why should questioned string respond here it contains an empty string at position 0?
>> Makes no sense for me.
> 
> Here's an analogy: (string-match "xyzzy" "fooxyzzybar") returns 3.
> This is because the first 5 characters starting at position 3 are
> "xyzzy", the same as the first string parameter.  The significance of
> 5 here is the length of "xyzzy".
> 

Well, string-match should tell first point of occurrence if any.
If we have none, as with slightly changed example

(string-match "xyzzy" "foox-a-yzzybar")
it duly returns "nil"  - and not "0" saying falsly "first point of non-occurence"


(string-match "" "fooxyzzybar") asks, if there is an empty string in string.
If yes, report the starting point of the empty string.

Does string start with an empty string? IMHO not.

Thanks all, interesting matter...

Andreas


> Similarly, (string-match "" "foo") returns 0.  This is because the
> first 0 characters starting at position are "", the same as the first
> string parameter.
>