Variable-width lookbehind

[OKB (not okblacke)]

Paul Rubin wrote:

> "OKB (not okblacke)" <brenNOSPAMbarn at NObrenSPAMbarn.net> writes:
>>          For years now Python has not supported variable-length
>>          lookbehinds.  
> 
> I'm not sure what that is and the perl links you gave don't work,
> but it sounds evil. 

    	The links work fine for me. . .

    	You're not sure what "variable-length lookbehinds" means?  
Lookbehind is something that Python regexps already have.  You can do 
"(?<=one)two" to match "two" only if it's preceded by "one", and you can 
do "(?<!one)two" to match "two" only if it's NOT preceded by "one".  
What you can't do is "(?<=one|three)two", because Python requires that 
the lookbehind contain only strings of a fixed length.  What I'm asking 
about is the possibility of lifting this limitation, to allow the 
lookbehinds (positive and negative) to contain general regexps.  I don't 
see how this is in any way evil.

-- 
--OKB (not okblacke)
Brendan Barnwell
"Do not follow where the path may lead.  Go, instead, where there is
no path, and leave a trail."
	--author unknown