Ah, you're right. I was thinking of the wrong exception and wrote the wrong test.
use Test::More 'tests' => 5;
sub is_code {
no warnings qw( void uninitialized );
return eval { defined &{$_[0]} };
}
sub real_sub { die 'real sub called' }
my $sub_ref = sub { die 'sub ref called' };
my $undef;
ok( is_code( \&real_sub ), 'real sub ref is code' );
ok( is_code( $sub_ref ), 'lexical sub ref is code' );
ok( ! is_code( $undef ), 'undef is not code' );
ok( ! is_code( 'string' ), 'string is not code' );
ok( is_code( 'real_sub' ), 'string is code' );
So you still need an extra check in is_code.
sub is_code {
no warnings qw( void uninitialized );
return '' ne ref $_[0] && eval { defined &{$_[0]} };
}
That's fairly simple, but I think I still prefer the battery of ref, Scalar::Util::reftype, Scalar::Util::blessed and overload::Method.
use strict;
use warnings;
use Test::More 'tests' => 16;
use Scalar::Util qw( blessed reftype );
my $side_effect = 0;
package OverloadCode;
use overload '&{}' => sub { $side_effect = 1; sub {} };
package main;
sub is_code_eval {
no warnings qw( void uninitialized );
return '' ne ref $_[0] && eval { defined &{$_[0]} };
}
sub is_code_util {
my $suspected_code = shift;
return 0 if '' eq ref $suspected_code;
return 1 if 'CODE' eq reftype $suspected_code;
if ( blessed $suspected_code
&& overload::Method( $suspected_code, '&{}' ) ) {
return 1;
}
return 0;
}
sub real_sub { $side_effect = 1 }
check_method( \&is_code_util, 'utils' );
check_method( \&is_code_eval, 'eval' );
sub check_method {
my ( $tester, $name ) = @_;
$side_effect = 0;
my $sub_ref = sub { $side_effect = 1 };
my $overcode = bless {}, 'OverloadCode';
my $undef;
ok( $tester->( \&real_sub ), "$name: real sub ref is code" );
ok( $tester->( $sub_ref ), "$name: lexical sub ref is code" );
ok( ! $tester->( $undef ), "$name: undef is code" );
ok( ! $tester->( 'string' ), "$name: string is not code" );
ok( ! $tester->( 'real_sub' ), "$name: real_sub as string is not c
+ode" );
ok( $tester->( $overcode ), "$name: overloaded reference is cod
+e" );
# this test fails for the eval method
ok( ! $side_effect, "$name: no side effect" );
is( $undef, undef, "$name: \$undef is still undef" );
}