Also, if you want to talk about performance, the way in which you're looking for variables to change is going to be much more of a problem. Since you're going through each field on each line, this is roughly O(n^2) in complexity. That could get really expensive if you're running those regexes on a large number of fields/lines. Rather than checking for all of the fields on each iteration of the while loop, you might do something like this: 

while(<MYTEMPLATE>){
  # get the names of the fields on this line  
  my @variables = $_ =~ m/<\?--(\S+?)-->/g;
  for my $variable ( @variables ){
    # replace the tag with the value of the variable
    # if there is one.
    s/<\?--$variable-->/$$variable/g if $$variable;
  }
}

[download]

That should yield something more like O(n), which should be noticeably faster in most cases (remember that O(n^2) smaller than O(n) for small numbers), less error prone and since it's dynamic, you won't have to update it when there's a new field to check.

In reply to Re: Performance Question by agianni
in thread Performance Question by Anonymous Monk

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