in reply to Syntax error with if following eval

eval {1};
if (1) {}

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Note the semi-colon!

Liz

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Re: Re: Syntax error with if following eval
by Anonymous Monk on Sep 08, 2003 at 21:28 UTC

    Ahhh, I see: thank you. ~sneaks off to hide shame~

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      Actually, I have been looking up why what you did was an error.

      If you think about a string eval, the problem would have been clearer, I think: 

      eval '1'
if (1) {}

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      but if you would write the block eval as: 

      eval {
    1
}
if (1) {
}

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      then it becomes very confusing and unclear why that would be a problem. I guess it's just one of the Perl's syntaxical quirks that you need to get used to.

      Liz

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        For what it's worth, I believe that the language design for Perl 6 specifies that the trailing semicolon after an eval block will become optional.
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        I think the problem is that the if is seen as a modifier to the eval statement, after which point the {} mucks up the parsing.

        You'd get the same error from: print "hahaha\n" if (1) {};

        So, in the eval case, perl thinks you want: eval { 1 } if ($@); but finds an extra block.

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        Thank you: I was trying to figure out why it was wrong myself. It didn't seem so very wrong, because I always associate {} with "code blocks" that don't require trailing ;'s. When you put it in terms of the string eval that makes it a lot clearer.

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