Re: japhy's regex article for the TPJ

Maybe this would be too esoteric or somewhat "ahead of its time", but a little more exposure for the unicode tricks that are now possible with Perl RE's could yield some useful surprises for the average reader.

For example, making up expressions and character classes with things like \p{Punctuation} or \p{CurrencySymbol} (or their short forms \p{P}, \p{Sc}) -- and having these work regardless of what language the text is in -- has a certain attraction to it. (Or maybe I just don't realize what a nerd I am to think so.)

Comment on Re: japhy's regex article for the TPJ

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Re: Re: japhy's regex article for the TPJ by japhy (Canon) on May 19, 2004 at 04:03 UTC
Actually, I'm glad you brought this up. In 5.8.4, there's improved ability (thanks to me) to create your own Unicode classes, and even build cascading ones. The documentation is in perlunicode, and here's an example (you must have Perl 5.8.4 for this to work): package MyUnicode; sub InLetters { return << 'END'; 0041 005a 0061 007a END } sub InVowels { return << 'END'; 0041 0045 0049 004f 0055 0061 0065 0069 006f 0075 END } sub InConsonants { return << 'END'; +MyUnicode::InLetters -MyUnicode::InVowels END } package main; my $string = "Chicken Stromboli"; while ($string =~ /(\p{MyUnicode::InConsonants}+)/g) { print "consonant cluster: '$1'\n"; } __END__ consonant cluster: 'Ch' consonant cluster: 'ck' consonant cluster: 'n' consonant cluster: 'Str' consonant cluster: 'mb' consonant cluster: 'l' [download] I could write about that, and explain the new '&' class operand, which allows you to do the intersection of two or more Unicode classes. I like this idea. Maybe I can do this and one other topic -- I don't want the article to be too widely scoped. _____________________________________________________ Jeff`[japhy]`Pinyan: Perl, regex, and perl hacker, who'd like a job (NYC-area) `s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;`	[reply] [d/l]

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Re: Re: japhy's regex article for the TPJ
by japhy (Canon) on May 19, 2004 at 04:03 UTC

perlunicode

package MyUnicode;

sub InLetters {
  return << 'END';
0041    005a
0061    007a
END
}

sub InVowels {
  return << 'END';
0041
0045
0049
004f
0055
0061
0065
0069
006f
0075
END
}

sub InConsonants {
  return << 'END';
+MyUnicode::InLetters
-MyUnicode::InVowels
END
}

package main;

my $string = "Chicken Stromboli";
while ($string =~ /(\p{MyUnicode::InConsonants}+)/g) {
  print "consonant cluster: '$1'\n";
}

__END__
consonant cluster: 'Ch'
consonant cluster: 'ck'
consonant cluster: 'n'
consonant cluster: 'Str'
consonant cluster: 'mb'
consonant cluster: 'l'
[download]

I like this idea. Maybe I can do this and one other topic -- I don't want the article to be too widely scoped.

_____________________________________________________
Jeff[japhy]Pinyan: Perl, regex, and perl hacker, who'd like a job (NYC-area)
s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;

[reply]
[d/l]