I'd hoped that. I'd heard enough people claiming otherwise that I guessed that perhaps Perl wasn't that smart.

I also noticed that none of the benchmarking code in this thread was making a straight substitution of /.../o with $qr between the cases. So I picked the code that had the most similar test cases and added one, got results even better than I expected, quadruple checked things because "better than expected benchmarks" almost always means "mistake made".

Adding another case for /$qr/, I get it being nearly identical to my $_ =~ $qr case (which is faster than /.../o, perhaps just because the qr/.../ part is done outside the scope of the benchmarking; but "fixing" that would be more work than I care to invest at this point).

So I suspect that diotalevi is correct in both that =~ /$qr/ and =~ $qr produce identical code and that the benchmark results showing qr// to be slower than //o have to do with other code differences between the cases and/or the order that operations get run (or chance).

Thanks, diotalevi.

                - tye

In reply to Re^4: Never (qr//) by tye
in thread Never-to-use Perl features? by Juerd

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.