This is kind of cool, but I've been severely bitten by source filters in the past, and continue to have a number of personal stylistic issues with using them. What I'd like to see (and if someone knows of a CPAN module that does this, I'd be grateful) is something that would allow subs to be written thusly: 

use Verifier;
my $verify = new Verifier (on_failure => sub { die(join (',',@_)) })

sub foobar {
    ## The '-' in front of hashref means $bar is an optional paramater
    my ($foo, $bar) = $verify->type ( \@_, qw/scalar -hashref/);
        
    print "Using $foo:\n";
    return $foo unless %$bar;
    for (keys %$bar) { print "$_ => $$bar{$_}\n" }
    return $$bar{'result'};
}

[download]

That is, I'd really like to see verification of parameter types handled by a verifier object rather than by a source filter. Yes, I know it's not quite the same thing; but by eval'ing the type verifier call, one could achieve the same basic functionality.

Update: It turns out, thanks to a mention by dragonchild and xdg, that Params::Validate does just the above. An example of the above code, but using that CPAN module, can be found a bit further down in this discussion.

radiantmatrix
require General::Disclaimer;
s//2fde04abe76c036c9074586c1/; while(m/(.)/g){print substr(' ,JPacehklnorstu',hex($1),1)}

In reply to Re: Use method/function signatures with Perl by radiantmatrix
in thread Use method/function signatures with Perl by Ovid

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.