in reply to regexp match repetition breaks in Perl

A match operation will always return exactly as many values as there are captures, so /(...)(?:(...))*(...)/ will always return exactly three results on a match. When using the g modifier, the match operation will always return an exact multiple of the number of captures. You need a parser.

Here's a simple solution: 

while ($text =~ m/
   (APC[s]?)
   (
      \s \d{3}
      (?:
         (?: , \s \d{3} )*
         \s and \s \d{3}
      )?
   )
/xg) {
   my ($apc, $nums) = ($1, $2);
   my @nums = $nums =~ /(\d+)/g;
   push @extracts, $apc, @nums;
}

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By the way, what's with pos($text) = 0 and the c switch? Removed!

Update: Added a solution.

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Re^2: regexp match repetition breaks in Perl
by barkingdoggy (Initiate) on Jul 11, 2007 at 23:14 UTC

    Thanks to ikegami et al. for setting me on the path of righteousness!


    Re pos($text), I'm doing multiple passes through the document, picking out different things on each pass. So, I need to reset the pos before each pass. 3-digit APC codes are just one of the passes.

    I am/was extracting "APC" to help debug the perl/regex. In the final version, I just will extract the code/number.

    Thanks, again!
[reply]

      So, I need to reset the pos before each pass. 3-digit APC codes are just one of the passes.

      Not quite. 

      $_ = 'a1!b2.c3?';
print $1 while /([abc])/g;  # abc
print $1 while /([123])/g;  # 123
print $1 while /([!.?])/g;  # !.?
print "\n";

      [download]

      Note the lack of the c modifier. That does exactly the opposite of what you want. It's purpose is to prevent pos from getting reset.

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