realizing AND in regex?

LanX has asked for the wisdom of the Perl Monks concerning the following question:

I'm using the regex engine to identify delimited fields matching certain conditions.

Thanks to Perl's internal trie optimization of OR-conditionsš it's far faster than using LIKE in mysql especially with hundreds of patterns to check

$text = 'A0 peter Z0 ...  A42 peter, paul and mary Z42 ... A99 mary Z9
+9';
 
my @or_matches = ( $text =~ m/A(\d+)[^Z]*(peter|mary)[^Z]*Z/g );
print "@or_matches \n";
__END__
0 peter 42 mary 99 mary
[download]

But now I got the requirement to find fields which match multiple regex at the same time ... and AFAIK the regex grammar doesn't have an AND operator

The best guess I have is using zero-look-ahead assertions:

$text = 'A0 peter Z0 ...  A42 peter, paul and mary Z42 ... A99 mary Z9
+9';
 
my @and_matches =( $text =~
               m/
                    A(\d+)[^Z]*
                    (
                        (?=mary)
                        [^Z]*
                        peter
                    |
                        (?=peter)
                        [^Z]*
                        mary
                    )
                    [^Z]*Z
                /xg );
 
print "@and_matches \n";
__END__
42 peter, paul and mary
[download]

Well, already rather complicated for just two patterns ... and I doubt that it's fast ... any better suggestions?

Cheers Rolf

UPDATE:

Ok the following is already much better since it avoids or-chaining all possible orders of patterns just by anchoring the look-ahead at field-start.

print @and_matches =( $text =~
               m/
                    A(\d+)
                    (
                        (?=
                            [^Z]*
                            mary
                        )
                        (?=
                            [^Z]*
                            peter
                        )
                        [^Z]*
                    )
                    Z\1
                /xg );
[download]

Footnotes:

š) >5.10 IIRC

Comment on realizing AND in regex? Select or Download Code

Replies are listed 'Best First'.
Re: realizing AND in regex? by BillKSmith (Monsignor) on Sep 13, 2012 at 12:26 UTC
It is certainly easier and posibly faster to use separate regexes. Use perl's logic rather than the regex engine to combine the results. Bill	[reply]
Re^2: realizing AND in regex? by LanX (Saint) on Sep 13, 2012 at 13:02 UTC
Faster than a trie? I certainly doubt. =) see Re:x2 A Regexp Assembler/Compiler (Whats a 'trie'?) Cheers Rolf	[reply]
Re^3: realizing AND in regex? by AnomalousMonk (Archbishop) on Sep 13, 2012 at 17:36 UTC
Why doubt? Benchmark!	[reply]
Re^4: realizing AND in regex? by LanX (Saint) on Sep 13, 2012 at 18:38 UTC
Re: realizing AND in regex? by pvaldes (Chaplain) on Sep 13, 2012 at 22:39 UTC
I got the requirement to find fields which match multiple regex at the same time `while (<DATA>){ if (/foo/ && /bar/){ print $_ } } __DATA__ fobur barfoo foobar fobar bar foo` [download]	[reply] [d/l]


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