Re: Function Prototypes

Your args as in the example are a hash, so in the absence of any indication of why you want to use prototypes the obvious works for me:

#!/usr/bin/perl -w
use strict;

my @aFieldHeaders;
my %hFieldConfigs;
sub ConfigRead (%);

my $sConfigFile = 'mydata.csv';
ConfigRead(sFILE => $sConfigFile,
           apHEAD => \@aFieldHeaders,
           hpFIELDCONF => \%hFieldConfigs);

# my array and hash now have some cool stuff in 'em!


sub ConfigRead (%) {
    my %hArgs = (
        sFILE    => 'BAD',      # lazy user alert! whine & die
        apHEAD  => 'BAD',       # ^^^ see comment above
        hpFIELDCONF => 'BAD',   # by now you know the drill!
        @_,                     # user demands come from here
    );
    
    # stick some cool stuff in their variables
}
[download]

But as everyone else has said: don't do that unless you have a good reason.

Comment on Re: Function Prototypes Download Code

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Re^2: Function Prototypes by KimberTLE (Initiate) on Nov 24, 2015 at 18:19 UTC
You, hippo, are my hero! And now that I see it, it makes perfect sense. Occam's Razor, after a good stropping. As promised: THANK YOU!	[reply]
Re^3: Function Prototypes by Your Mother (Archbishop) on Nov 24, 2015 at 18:32 UTC
I do encourage you to read the link AnomalousMonk provided: Far More than Everything You've Ever Wanted to Know about Prototypes in Perl -- by Tom Christiansen. Prototypes as argument checking is nearly always a mistake, no lie.	[reply]
Re^4: Function Prototypes by KimberTLE (Initiate) on Nov 25, 2015 at 02:21 UTC
Thanks! Own it, and I've read it. But messing with "named arguments" raised the question in my mind, "how would you prototype something like this?" And after too many sleepless millennia, I relented and had to ask! But kind of like... `Paris in the the spring time` [download] Once you've written it, the correct answer eludes you forever. Again, thanks for supplying the two-by-four. Greatly appreciated!	[reply] [d/l]
Re^3: Function Prototypes by AnomalousMonk (Archbishop) on Nov 25, 2015 at 05:10 UTC
I still do not understand your original reasons for wanting to use prototypes, nor do I know if hippo's reply has dissuaded you, but if you are not dissuaded, here's an example of why prototypes are not useful as you seem to wish to use them: `c:\@Work\Perl\monks>perl -wMstrict -le "use Data::Dump qw(dd); ;; sub S_ { my %h = @_; dd \%h; } sub Sh (%) { my %h = @_; dd \%h; } sub Sa (@) { my %h = @_; dd \%h; } ;; S_(qw(a b c)); Sh(qw(a b c)); Sa(qw(a b c)); " Odd number of elements in hash assignment at -e line 1. { a => "b", c => undef } Odd number of elements in hash assignment at -e line 1. { a => "b", c => undef } Odd number of elements in hash assignment at -e line 1. { a => "b", c => undef }` [download] The warning is in the `'misc'` class, and escalating such warnings to `FATAL`ity would at least prevent the code from soldiering on regardless, but of course that has nothing to do with the prototype. Give a man a fish: `<%-{-{-{-<`	[reply] [d/l] [select]