Dear Esteemed Monks,

In an effort to squeeze the utmost speed out of a large-scale lexical processing program I'm working on, I encountered advice that subs are slow in Perl; I have two functions in my program: one that recursively traverses a directory structure finding files, and one that takes those files and processes them entry by entry. In an attempt for a speed-boost I'm trying to remove those subs and make them in-line loops. So, two questions:

Question 1: is it worth it?

in the end, my directory-search routine will be called over an upward bound of around 100,000 files in several directories. Each time, it will call the second routine (processing the individual files). Would the gains be likely to be worth making this a loop instead of a sub?

Question 2: how to rewrite File::Find recursive function calls?

The sub looks like this, with the recursive line being the 'find' line :

sub _process_files {
    my $file = shift;
   ... 
    # .json file
    if (-f $file and ($file =~ /\.json\Z/)) {
    _process_json($file);
    }
    # Directory
    elsif (-d $file) {
    # for each file in directory, process
    find ( { wanted => sub { \&_process_files($File::Find::name) if -f
+}, 
         no_chdir => 1 }, "$file");
    }
}

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In reply to Efficiency: Recursive functions while de-subbing my program by Endless

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