context sensitiveness

context.pl

#!/usr/bin/env perl

use warnings;
use strict;

use Carp 'cluck';

sub worker {
  my $ctx =
    defined wantarray.
      ? wantarray
        ? 'LIST'.
        : 'SCALAR'
      : 'VOID'
  ;
  cluck "worker() has been called in $ctx context";
  warn "\n";
  my @ret = (qw/a b c/);
  return @ret;
}

sub call_void {
  worker();
  cluck "Result is: N/A";
}

sub call_scalar {
  my $res = worker();
  cluck "Result is: $res";
}

sub call_list {
  my @res = worker();
  cluck( "Result is: " . join ', ', @res );
}

for (qw/scalar list void/) {
  my $m = "call_$_";
  __PACKAGE__->$m;
  warn "\n\n";
}