> Yes, but just having a more complete implementation of PCRE regex would make
> a big difference.
> For example, LC's regex does not include back references.
> Having the ability to use (PCRE compliant) back references would, I believe,
> in many case, eliminate the need for that array of matches.
> For example....
>> The dictionary says "LiveCode implements regular expressions compatible with
>> the PCRE library." Without back references the LC implementation is a rather
>> limited subset of that library.
Sorry to be a bit more precise, but actually back references *are*
implemented. You can use them in the pattern matching, as:
" (.)\1"
I let the reader find what's for :)
A regex engine needs 2 input: a text and a pattern matching
and it returns true or false plus a list (generic word)
of index if any captures. That's it. Everything else is *not* part
of the regex engine.
That said, implementing back references in the replacement text
is and only is the responsability of Livecode engine! (see below)
>> Example:
>> I would expect to be able to do this in the message box:
>> put replaceText("abcd","(ab)(cd)","$2$1")
>> and get this:
>> "cdab"
Well, change $1 $2 by \1 and \2 and it will be less Perlish
plus this syntax is already in use.
What a pity you didn't manifest yourself here and at this time:
http://forums.livecode.com/viewtopic.php?f=66&t=17412
I dropped all, feeling a bit lonely on this path..
>> Instead I have to do this:
>> if matchText("abcd","(ab)(cd)",var1,var2) then put var2 & var1
>>
>> But this is a trivial example. If either my string to search or my pattern
>> is slightly more complex, then what would be a trivial task with full PCRE
>> compliant regex becomes comparatively complicated in LC.
Yes, speaking from experience, Perl and Regex are just "Wow"
and they are fast; yes, fast!
Why do you think I spent so much time developping a
Perl external for Livecode some years ago.
And if you don't believe a French guy, check how geneticians
work with huge databases and DNA files..
Regards,
Thierry
------------------------------------------------
Thierry Douez - http://sunny-tdz.com
Maker of sunnYperl - sunnYmidi - sunnYmage
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