cadphile has asked for the wisdom of the Perl Monks concerning the following question:
I have what seems like a simple parsing problem, but am stumped. I have single lines in input with repeated patterns of arbitrary length that match this general format (whown with 3 patterns):
I want to build a parser that loops through the input line and repeatedly extracts either the token "AND" or "OR", and then eats up everything in the line until the next "AND" or "OR", or EOL whichever comes first. I've tried this:$str = q!AND (random text) AND (more random text) AND (yet more)!; $str = q!OR (random text) OR (more random text) OR (yet more)!;
but that doesn't work -- the 2nd pattern eats everything to the EOL. Since the 2nd pattern is bounded by parens, I've tried this:while ($str =~ /\G(AND|OR)\s+(.+?)/g) { printf("%s %s\n", $1, $2); }
This does work, however, if the "random text" includes any parens itself, then the pattern match fails, by matching the first end-parenthesis in the text. E.g. this string breaks the pattern match:while ($str =~ /\G(AND|OR)\s+(\(.+?\))/g) { printf("%s %s\n", $1, $2); }
$str = q!AND (random text) AND (yet (more))!;
What's a good way to eat up the line, capturing the "AND" or "OR" token in $1, and the "random text" in $2, on and on until we hit the EOL. Your regex expertise is appreciated.
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Replies are listed 'Best First'. | |
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Re: simple perl regex question (or is it?)
by LanX (Saint) on Nov 11, 2013 at 00:02 UTC | |
by cadphile (Beadle) on Nov 11, 2013 at 01:41 UTC | |
by AnomalousMonk (Archbishop) on Nov 11, 2013 at 18:30 UTC | |
by Anonymous Monk on Nov 11, 2013 at 07:45 UTC | |
Re: simple perl regex question (or is it?)
by ww (Archbishop) on Nov 11, 2013 at 00:12 UTC | |
Re: simple perl regex question (or is it?)
by hdb (Monsignor) on Nov 11, 2013 at 09:13 UTC | |
Re: simple perl regex question (or is it?)
by AnomalousMonk (Archbishop) on Nov 11, 2013 at 15:46 UTC |
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