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Re: A demanding parser (THE SOLUTION)

by gmax (Abbot)
on Jan 31, 2002 at 06:59 UTC ( #142382=note: print w/ replies, xml ) Need Help??


in reply to Re: Re: Re: Re: A demanding parser
in thread A demanding parser

It works! I had some trouble figuring out how to implement it, because with 'use strict' the recursive RegEx stays undefined.

#!/usr/bin/perl -w use strict; my $input = "aa (bb cc) dd (ee (ff (gg) hh) jj) kk ((ll)) mm"; no strict 'vars'; # from $RE{balanced}{-parens=>'()'}; $REparens = qr/ (?:(?:(?:[(](?:(?>[^)(]+) |(??{$REparens}))*[)])) |(?:(?!)))/x; my $re = $REparens; use strict; print "input: $input\n"; while ($input =~ /\G(\w+|$re)\s*/gc) { print "$1\n" } __END__ output: aa (bb cc) dd (ee (ff (gg) hh) jj) kk ((ll)) mm
Making a block of no strict 'vars' solves the problem. There I can assign the recursive regex to a proper ly declared variable, or call explicitly ($main::REparens).
Thanks a million.
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