Update: As blazar so kindly pointed out, the (@) prototype is indeed meaningless. It just goes to show how useful it is to reread the docs every once in a while. I'd filed away the fact that prototypes let you do cool stuff and omit parens. Which they do, but not in the way that I understood it at the time I first read the docs.

Reread the docs from time to time. It's amazing what you can learn!

Back to my regularly scheduled foolishness...

The % and @ prototypes do the same thing--eat an entire list. Your suggestion that it should check for evenness is very good. It's in my battered old copy of Perl in a Nutshell, it works, but I don't see it in perlsub--interesting...

I used the % prototype despite its identicalness with @ just to clearly show my intentions--that is mkhref wants a hash. I'm not sure about that decision now, since it turns out to be a partially documented feature :).

The prototypes allow you to skip your parentheses, which makes the sub act more like a built-in. Since you said you wanted a built-in, I thought I'd fake it as well as can be done. 

mkaref( 1..9 );
# becomes
mkaref 1..9;

[download]

In a module, I'd have mkhref check for warnings, with $^W. If on, it should carp, that way the error refers to the "right" line of code. 

sub mkhref (%) {
    if ( @_%2 ) {
        carp "Odd number of elements in mkhref" if $^W;
        return { @_, undef };
    }
    else {
        return {@_};
    }
}

[download]


TGI says moo

In reply to Re^3: Half-serious quest for prefix anonymous refs taking by TGI
in thread Half-serious quest for prefix anonymous refs taking by blazar

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