Re: is there an easy way to dumb down this regular expression for me?

It also accepts an empty string, since you've got a doubled '|' in there. One | separates alternatives, not two.

As for dumbing it down, I'd rewrite it like so:

$A_rx = qr{ \Q $A }x;
$w_rx = qr{ \Q $w }x;

$rx = qr{
  $A_rx \s*
  \*? \s*
  cos \s*
  (?:
    \( \s* $w_rx \s* \*? \s* t \s* \)
    | $w_rx \s* \*? \s* t \s
  ) \s*
  A
}x;
[download]

Then you can use it in the following manner: $string =~ /^\s*($rx)\s*$/.

Jeff japhy Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and perl hacker
How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart

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Re^2: is there an easy way to dumb down this regular expression for me? by diotalevi (Canon) on Oct 19, 2005 at 20:42 UTC
A nit - you'll notice that $re is assigned '/.../', not a qr expression. I prefer your assignment of the qr// but its worth noting.	[reply] [d/l]
Re^2: is there an easy way to dumb down this regular expression for me? by moltar512 (Sexton) on Oct 19, 2005 at 20:48 UTC
thanks! but i have to ask a few more questions yours is infintely more easy to read.. but now i'm trying to figure out what you did using http://www.perlmonks.net/?node=perlop what does the x behind all of your qr{ ... }x mean?	[reply]
Re^3: is there an easy way to dumb down this regular expression for me? by davidrw (Prior) on Oct 19, 2005 at 21:35 UTC
Look at perlre as well for the `/x` modifier: x Extend your pattern's legibility by permitting whitespace and comments. It was used so that everything could be spaced out for clarity -- that's also why al the `\s*` are in there because when using /x you have to explicitly say when you actually want to match whitespace.	[reply] [d/l] [select]