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154

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1
+6  Q: 

What class of language can Perl regular expressions be used against?

I know that some of the capabilities of the Perl regular expression engine are not regular. However, what class is it? It might be context-free, but CS theory was never my strongest subject.

+2  A: 

Actually, many implementations are neither regular nor context-free; patterns have become their own beast. This Wikipedia article has more on this, including a bit from Larry Wall, the author of the Perl language.

geowa4  2009-09-30 14:27:15
I was just going to link to this exact same page :)
Pierre Bourdon  2009-09-30 14:30:43

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