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Re: string-match bug?


From: Andreas Röhler
Subject: Re: string-match bug?
Date: Tue, 08 Dec 2009 14:55:33 +0100
User-agent: Thunderbird 2.0.0.19 (X11/20081227)

Peter Dyballa wrote:
> 
> Am 08.12.2009 um 11:50 schrieb Andreas Röhler:
> 
>> Barry Margolin wrote:
>>> In article <address@hidden>,
>>> Matthew Dempsky matthew dempsky wrote:
>>>
>>> Here's another example of a limit case:
>>>
>>> (string-match "a*" "b") returns 0, because a* matches zero or more a's,
>>> and there are zero a's at position 0.
>>>
>>
>> Hmm, interesting
>>
>> IMHO that differs:
>>
>> (string-match "a*" "b") asks for a non-occurrence too. So "0" of first
>> position is plausible.
> 
> 
> Aren't the regular expressions "" and "a*" equivalent in that respect
> that they both also match the empty string?
> 

...

Ah, see some point now. If I take the "a", nothing is left...

OTOH if (string-match "a*" "b") returns NIL, will that be less plausible?

Not sure... However, see current behavior conforms to POSIX

http://www.opengroup.org/onlinepubs/009695399/

So I'll simply keep it in mind, hopefully...


Thanks all again

Andreas









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