Re^2: Python 'is' command

... 'is' ... is overkill ...

I strongly agree! What's the point of bringing Scalar::Util::refaddr() et al to the party when == != (and all the other numeric comparators, in the unlikely event they would be of any use) seem to manage just fine:

c:\@Work\Perl\monks>perl
use strict;
use warnings;

use Test::Simple tests => 4;
1..4

sub is { $_[0] == $_[1] }

my $x = 3;
my $y = 3;

my $x_ref = \$x;

my $test_ref_1 = \$x;
my $test_ref_2 = \$y;

ok(  is($test_ref_1, $x_ref), 'is Same'      );
ok( !is($test_ref_2, $x_ref), 'is Different' );

ok( $test_ref_1 == $x_ref, '==' );
ok( $test_ref_2 != $x_ref, '!=' );

__END__
ok 1 - is Same
ok 2 - is Different
ok 3 - ==
ok 4 - !=
[download]

Give a man a fish: <%-{-{-{-<

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Re^3: Python 'is' command by haukex (Archbishop) on Aug 14, 2019 at 19:33 UTC
What's the point of bringing Scalar::Util`::refaddr()` et al to the party when `==` `!=` (and all the other numeric comparators ... seem to manage just fine Because it's the only solution in the whole thread that still works even in the presence of operator overloading? `;-)` `use warnings; use strict; package Foo { my $x; use overload '<=>'=>sub{1}, 'cmp'=>sub{1}, '0+'=>sub{++$x}; } my $x = bless {}, 'Foo'; my $y = $x; print $x==$y ? "True\n" : "False\n"; # False use Scalar::Util qw/refaddr/; sub is { return refaddr $_[0] == refaddr $_[1] } print is($x,$y) ? "True\n" : "False\n"; # True` [download]	[reply] [d/l] [select]
Re^4: Python 'is' command by AnomalousMonk (Archbishop) on Aug 15, 2019 at 02:43 UTC
Hmm... Hadn't thought about that. Give a man a fish: `<%-{-{-{-<`	[reply] [d/l]
Re^5: Python 'is' command by haukex (Archbishop) on Aug 15, 2019 at 06:46 UTC
Some of my first thoughts whenever it's about breaking some expected behavior are usually: prototypes, tied variables, and operator overloading `:-)`	[reply] [d/l]
Re^3: Python 'is' command by BillKSmith (Monsignor) on Aug 14, 2019 at 20:22 UTC
Your comment clarifies exactly what I meant. However, the documentation of the refaddr function in Scalar::Util assures us that our operatores are comparing addresses. The user documentation for references (perlref) makes no such claim. Bill	[reply]
Re^3: Python 'is' command by bliako (Abbot) on Aug 14, 2019 at 21:17 UTC
you assume references. I don't know what python's is() does but I would expect any Perl is() to handle both `is($x,$y)` and `is(\$x, \$y)`.	[reply] [d/l] [select]