Harry Putnam wrote:
#!/usr/local/bin/perl
use strict;
use warnings;
my $var1 = 'whoopdee';
my $var2 = 'do';
my %dispatch = (
y => \&yy($var1,$var2),
this, actually, is not a code reference but a return value reference of
the &yy($var1, $var2) subroutine call, executed right at the time of
%dispatch assignment. By using (...) after a subroutine name you have
the subroutine executed and get its return value. Then, the leading '\'
in this syntax makes a reference to that return value.
To see what has happened, try to run your code in debug mode (perl -d)
and view the contents of your %dispatch hash, or place
use Data::Dumper;
print Dumper { %dispatch };
somewhere after %dispatch assignment. I saw the following:
$VAR1 = {
'y' => \'You pressed `y\',whoopdee do .. but why?
',
'n' => sub { "DUMMY" },
'q' => sub { "DUMMY" },
'error' => sub { "DUMMY" }
};
n => sub { print "You pressed \`n' \n";},
q => sub { print "Goodbye\n" and exit;},
error => sub { print "invalid selection\n" }
);
while(1)
{
print "press y \n",
"press n \n",
"press q to Exit\n";
chomp(my $selection = <STDIN>);
my $code = $dispatch{$selection} || $dispatch{'error'} ;
$code->();
this is the place you really want to call your subroutine, so also the
place to pass your arguments to it:
$code->($var1, $var2);
}
sub yy {
my ($var1,$var2);
($var1,$var2) = (shift,shift);
why not:
my ($var1, $var2) = @_;
or
my $var1 = shift;
my $var2 = shift;
?
my $retstr = sprintf "You pressed \`y',$var1 $var2 .. but why?\n";
return $retstr;
}
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