If I define it in qr/(?:[.,:;] ?| )/ and use the variable in the regular expression ...

This does not directly address your performance concerns, but when qr//-defined regex objects are interpolated into other regexes, either qr//, m// or s///, the process is more or less like string interpolation; the new regex does not somehow "call back" to the interpolated regex as a subroutine call within another subroutine would do.

To get a feel for this process, write and run (with full warnings and strictures) some code like the following, which just prints compiled regexes. (This is untested because I can't provide a working example at the moment.) Note that qr// automatically encapsulates its pattern in a  (?:...) non-capturing group that preserves the regex modifier flags, so the non-capturing grouping within  qr/(?:[.,:;] ?| )/ is redundant (but does no harm); try it both ways. 

my $foo = qr/[.,:;] ?| /;
print $foo, "\n";

my $bar = qr{ $foo+ (?: hic | hac | hoc) }xms;
print $bar, "\n";

my $baz = qr{ $bar{42} f[eio]e }xms;
print $baz, "\n";

[download]

Give a man a fish:  <%-(-(-(-<

In reply to Re: Improving performance by AnomalousMonk
in thread Improving performance by dominic01

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.