Re: Re: Using a paramter value to call a module

Interesting solution, but could you please explain the eval statement in the require_if_present sub? It looks as if you are using a here document, but would a try-catch-block eval not be more appropriate here? E.g.

sub require_if_present {
   my $mod = shift;
   eval {
      require $mod;
      return 1;
   }
   return 0 if $@;
}
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pike

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Re: Re: Re: Using a paramter value to call a module by ihb (Deacon) on Feb 07, 2003 at 15:04 UTC
`require()` has different meanings depending on the argument. See perlfunc. It even has an example of what you're trying to do, and why it's helps to use `eval EXPR`. <nit>`eval` requires a semi-colon after it.</nit> `ihb`	[reply] [d/l] [select]
Re: Re: Re: Using a paramter value to call a module by hawtin (Prior) on Feb 08, 2003 at 10:07 UTC
Interesting solution, but could you please explain the eval statement in the require_if_present sub? It looks as if you are using a here document, but would a try-catch-block eval not be more appropriate here? TMTOWTDI: That just happens to be the way I implemented it. A here document is convenient for some of the other things I do this way, but that is not a good reason to use it here. Using an `eval` as you suggest sounds like a cleaner approach. But against that this works (I have used it many times in the last year) and I try not to fix things that work. Update: Thinking about this last night I realised why I used a here document to do an eval, its because this was a very common construct in Perl 4 (now that is a really bad reason for doing it here).	[reply]