in reply to multiple (different) substitutions on same $foo

I don't know if it is a good idea or not, but yes, it is possible. 

for ( $foo ) {
  s/frog/toad/g;
  s/man/boy/;
  s/woman/girl/;
}

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Explanation: This is equivalent to the following where the default and magic $_ variable is implicit in several locations: 

for $_ ( $foo ) {
  $_ =~ s/frog/toad/g;
  $_ =~ s/man/boy/;
  $_ =~ s/woman/girl/;
}

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Another magic thing going on here is that the $_ is aliased to the value(s) in the list so that the substitutions are actually modifying $foo.

-- Eric Hammond

Replies are listed 'Best First'.
Re: Re: multiple (different) substitutions on same $foo
by welchavw (Pilgrim) on Aug 22, 2003 at 13:44 UTC
    Its picky, but I personally don't like the use of an iterative approach here (feels like "shoe-horning", kinda like the freaky NT/2000 command shell forces you to use "for" to get simple command substitution) with the "for" and might prefer a form that, nonetheless, still uses $_. I can easily see how folks might dislike that print stmt at the end, though, hmmmm.... 
    $_ = "A man and a woman saw a frog by the pond\n";
s/frog/toad/g, s/man/boy/, s/woman/girl/, print $foo = $_;

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Re: Re: multiple (different) substitutions on same $foo
by jonnyfolk (Vicar) on Aug 22, 2003 at 07:39 UTC
    Thanks for your reply, Eric. Why do you think it might not be a good idea?
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      If your code is as simple as the sample you presented (three substitutions), then I believe your original style is probably faster and much clearer than the other alternatives proposed.

      If you actually have dozens of substitutions to make, then I think it may be worth trying out one of the abstractions offered, though performance should be tested if it is a possible concern.

      -- Eric Hammond

[reply]
        Why would you want to change the code??? Why change something that works and is so simple a Shade Tree Coder with an Elementary School Diploma (<<< that would be me) can follow it??? Isn't that by definition excellent code???
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