In this application you can replace the given/when with a dispatch table. Other changes you can make since you use v5.36;:

The each() built-in is discouraged because there is only a single iterator for a given hash, which can be reset in un-obvious ways -- see the docs for each() for details.

My take on your boilerplate, with all the above incorporated, is:

#!/usr/bin/env perl

use v5.36;     # was 'use 5.010;'
#use warnings; # unnecessary now!
#use strict;   # unnecessary since 5.12.
no warnings 'experimental::for_list';
#no if $] >= 5.018, warnings =< "experimental::smartmatch";
use Getopt::Std;
my %opts;
getopts( 'hvi:', \%opts ) or die "getopts failed\n";
my $verbose;
my $infile;
for my ( $k, $v ) ( %opts ) {
    state $dispatch = {
	h => sub { ...; },
	v => sub { ++$verbose; },
	i => sub { $infile = $_[1]; },
    };
    my $code = $dispatch->{$k}
	or die "*** BUG: no handler for -$k.\n";
    $code->( $k, $v );
}

Note that the subroutines in the dispatch table do not close over your loop variables, so you must pass them in explicitly.


In reply to Re: v5.36 syntax error around given/when by Anonymous Monk
in thread v5.36 syntax error around given/when by ibm1620

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.