Re: The fastest way of searching a certain element in an array

[blakem]

Try the first() function List::Util. Its like grep but returns as soon as it finds the first match.

% perldoc List::Util

first BLOCK LIST
           Similar to "grep" in that it evaluates BLOCK setting $_ to 
+each
           element of LIST in turn. "first" returns the first element 
+where
           the result from BLOCK is a true value. If BLOCK never retur
+ns true
           or LIST was empty then "undef" is returned.

               $foo = first { defined($_) } @list    # first defined v
+alue in @list
               $foo = first { $_ > $value } @list    # first value in 
+@list which
                                                     # is greater than
+ $value

[ccn]

Hmm..., surely it is not the fastest. Here is it's code:

sub first (&@) {
  my $code = shift;

  foreach (@_) {
    return $_ if &{$code}();
  }

  undef;
}

You can see, it is similar to my for_block which was benchmarked.

[Limbic~Region]

ccn,
Here is it's code:

Well that depends. As I indicated in Getting Matching Items From An Array, List::Util falls back to pure perl (which has obvious inefficiencies) only if the XS version is unavailable. Which version of 'first' did you use in your benchmarks?

[ccn]

I benchmarked 'first' with XS loaded. To make shure that XS was loaded I've inserted some alerting printouts in pure perl version of the 'first'.

[adamk]

Or even better List::MoreUtil::any, which is EXACTLY what you mean. Boolean yes/no, instead of something that might suffer autoboolification and end up false.