in reply to Operator precedence (or, I'm an idiot)

Just another reason that grep (or map) in a void context should generate a warning.

I'm also curious why the simple version of your code reports 

    Found = in conditional, should be ==

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but the full version does not.

                - tye

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Re: Re: Operator precedence (void context)
by rir (Vicar) on Mar 07, 2003 at 22:02 UTC
    With the routine the $var may vary.

    Even with: 

      sub rout {
       &blah;
        1;
  }

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    there may be side effects.
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      Of course there may be side effects. That is why you don't have to use -w. But there is no good reason to use grep and/or map solely for their side effects and there are good reasons to not do so. The warning would be: 

          Use of map/grep in void context, use foreach instead

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      If you have some perverse reason for doing such, then just turn off that warning. For people wanting help in catching simple errors, the warning will be useful.

                      - tye
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[d/l]
        As to how Perl can be improved. I agree with tye, map and grep should generate a warning in void context. I'd leave out the foreach recommendation except under diagnostics.

        In the same vein, Perl should have a wantvoid or wantbool operator so that the general case can be handled.

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