Hello $h4X4_|=73}{,

These lines look strange to me:

if (exists $xlist{$name} && defined $xlist{$name}) {
 $xlist{$name} = undef; # this exists now

[download]

However, if the logic is correct, you can gain a little speedup by removing the first test:

if (defined $xlist{$name}) {

[download]

Testing for definedness on a non-existent hash entry doesn’t raise a warning, and won’t trigger autovivification, as the following demonstrates:

22:44 >perl -Mstrict -MData::Dump -wE "my %h = (a => 1, b => undef); d
+d \%h; say $_, defined $h{$_} ? ': yes' : ': no' for qw(a b c); dd \%
+h;"
{ a => 1, b => undef }
a: yes
b: no
c: no
{ a => 1, b => undef }

22:47 >

[download]

Hope that helps,

Athanasius <°(((>< contra mundum Iustus alius egestas vitae, eros Piratica,

In reply to Re: Speeding up a Perl code. Can it be faster? by Athanasius
in thread Speeding up a Perl code. Can it be faster? by $h4X4_&#124;=73}{

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.