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|
#!./perl
#
# test the logical operators '&&', '||', '!', 'and', 'or', 'not'
#
BEGIN {
chdir 't' if -d 't';
@INC = '../lib';
require './test.pl';
}
plan tests => 17;
for my $i (undef, 0 .. 2, "", "0 but true") {
my $true = 1;
my $false = 0;
for my $j (undef, 0 .. 2, "", "0 but true") {
$true &&= !(
((!$i || !$j) != !($i && $j))
or (!($i || $j) != (!$i && !$j))
or (!!($i || $j) != !(!$i && !$j))
or (!(!$i || !$j) != !!($i && $j))
);
$false ||= (
((!$i || !$j) == !!($i && $j))
and (!!($i || $j) == (!$i && !$j))
and ((!$i || $j) == ($i && !$j))
and (($i || !$j) != (!$i && $j))
);
}
my $m = ! defined $i ? 'undef'
: $i eq '' ? 'empty string'
: $i;
ok( $true, "true: $m");
ok( ! $false, "false: $m");
}
my $i = 0;
(($i ||= 1) &&= 3) += 4;
is( $i, 7, '||=, &&=');
my ($x, $y) = (1, 8);
$i = !$x || $y;
is( $i, 8, 'negation precedence with ||' );
++$y;
$i = !$x || !$x || !$x || $y;
is( $i, 9, 'negation precedence with ||, multiple operands' );
$x = 0;
++$y;
$i = !$x && $y;
is( $i, 10, 'negation precedence with &&' );
++$y;
$i = !$x && !$x && !$x && $y;
is( $i, 11, 'negation precedence with &&, multiple operands' );
|
