You had a bug. The alternation || is only written with *one* pipe character. The zero length pattern between each of the |s is also available so you could match anything that /^\s*$/ would match. The \Q...\E means quotemeta(). I've removed the \Q$A\E by doing quotemeta outside teh regexp. Since quotemeta has no effect on stuff like t and A, I removed it from those as well. I factored out the common parts of the expression so they aren't repeated. I also used the /x flag so I could add in as much extra whitespace as a I want - makes it easier to read. You'll notice how now everything except one branch of the alternation is followed by optional whitespace. That's to prevent "tA" from matching.

$A = quotemeta -4;
$w = quotemeta 500;

  $re =
  '/^  \s*
   $A \s*
   -? \s*
   cos \s*
   (?: \( \d+ t \)
     | \d+ t \s ) \s*
   A \s*
   $/x;

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In reply to Re: is there an easy way to dumb down this regular expression for me? by diotalevi
in thread is there an easy way to dumb down this regular expression for me? by moltar512

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