http://www.perlmonks.org?node_id=586680


in reply to Increasing the efficiency of the code

I don't know if it would actually increase performance but since the whole thing seems to be about wrapping from numerical to string context that gave me an idea. If you implemented a hash with the numerical operators as keys and the string operators as their corresponding values couldn't you rewrite the whole if elsif else etc construct as: 
if (eval "$conwithposition{$key_pos}[1] $mapContext{$conwithposition{$
+key_pos}[0] $line[$key_pos]"){
          foreach $col(sort {$a<=>$b} keys(%cols_pos)){
              push @tmparr,$line[$col];
          }
          $tmparr=join("|",@tmparr);
          push @listcols,$cols_pos{$col};
          push @result_arr,[ $tmparr ];

[download]

--
"WHAT CAN THE HARVEST HOPE FOR IF NOT THE CARE OF THE REAPER MAN"
-- Terry Pratchett, "Reaper Man"

Replies are listed 'Best First'.
Re^2: Increasing the efficiency of the code
by Limbic~Region (Chancellor) on Nov 29, 2006 at 13:14 UTC
    Fengor,
    If you implemented a hash with the numerical operators as keys and the string operators as their corresponding values couldn't you rewrite the whole if elsif else etc construct as:

    You have a good idea and yes, it will lead to a performance increase. Unfortunately your implementation is less than desireable. Using a string eval can be very dangerous and should be avoided when better alternatives exist. In this case, a dispatch table is better suited. See my post below for an example.

    Cheers - L~R

[reply]
      hmm thx, at least tis good to know i wasnt totally on the wrong track. That dispatch table looks good guess its about time to add that trick to my book ;)

      --
      "WHAT CAN THE HARVEST HOPE FOR IF NOT THE CARE OF THE REAPER MAN"
      -- Terry Pratchett, "Reaper Man"

[reply]

In Section Seekers of Perl Wisdom