| 1 | #!./perl -w |
| 2 | |
| 3 | BEGIN { |
| 4 | chdir 't' if -d 't'; |
| 5 | require './test.pl'; |
| 6 | set_up_inc('../lib'); |
| 7 | } |
| 8 | |
| 9 | plan tests => 24; |
| 10 | |
| 11 | # not() tests |
| 12 | pass("logical negation of empty list") if not(); |
| 13 | is(not(), 1, "logical negation of empty list in numeric comparison"); |
| 14 | is(not(), not(0), |
| 15 | "logical negation of empty list compared with logical negation of false value"); |
| 16 | |
| 17 | # test not(..) and ! |
| 18 | note("parens needed around second argument in next two tests\nto preserve list context inside function call"); |
| 19 | is(! 1, (not 1), |
| 20 | "high- and low-precedence logical negation of true value"); |
| 21 | is(! 0, (not 0), |
| 22 | "high- and low-precedence logical negation of false value"); |
| 23 | is(! (0, 0), not(0, 0), |
| 24 | "high- and low-precedence logical negation of lists"); |
| 25 | |
| 26 | # test the return of ! |
| 27 | { |
| 28 | my $not0 = ! 0; |
| 29 | my $not1 = ! 1; |
| 30 | |
| 31 | no warnings; |
| 32 | ok($not1 == undef, |
| 33 | "logical negation (high-precedence) of true value is numerically equal to undefined value"); |
| 34 | ok($not1 == (), |
| 35 | "logical negation (high-precedence) of true value is numerically equal to empty list"); |
| 36 | |
| 37 | use warnings; |
| 38 | ok($not1 eq '', |
| 39 | "logical negation (high-precedence) of true value in string context is equal to empty string"); |
| 40 | ok($not1 == 0, |
| 41 | "logical negation (high-precedence) of true value is false in numeric context"); |
| 42 | ok($not0 == 1, |
| 43 | "logical negation (high-precedence) of false value is true in numeric context"); |
| 44 | } |
| 45 | |
| 46 | # test the return of not |
| 47 | { |
| 48 | my $not0 = not 0; |
| 49 | my $not1 = not 1; |
| 50 | |
| 51 | no warnings; |
| 52 | ok($not1 == undef, |
| 53 | "logical negation (low-precedence) of true value is numerically equal to undefined value"); |
| 54 | ok($not1 == (), |
| 55 | "logical negation (low-precedence) of true value is numerically equal to empty list"); |
| 56 | |
| 57 | use warnings; |
| 58 | ok($not1 eq '', |
| 59 | "logical negation (low-precedence) of true value in string context is equal to empty string"); |
| 60 | ok($not1 == 0, |
| 61 | "logical negation (low-precedence) of true value is false in numeric context"); |
| 62 | ok($not0 == 1, |
| 63 | "logical negation (low-precedence) of false value is true in numeric context"); |
| 64 | } |
| 65 | |
| 66 | # test truth of dualvars |
| 67 | SKIP: |
| 68 | { |
| 69 | my $got_dualvar; |
| 70 | eval 'use Scalar::Util "dualvar"; $got_dualvar++'; |
| 71 | skip "No Scalar::Util::dualvar", 3 unless $got_dualvar; |
| 72 | my $a = Scalar::Util::dualvar(3, ""); |
| 73 | is not($a), 1, 'not(dualvar) ignores int when string is false'; |
| 74 | my $b = Scalar::Util::dualvar(3.3,""); |
| 75 | is not($b), 1, 'not(dualvar) ignores float when string is false'; |
| 76 | my $c = Scalar::Util::dualvar(0,"1"); |
| 77 | is not($c), "", 'not(dualvar) ignores false int when string is true'; |
| 78 | } |
| 79 | |
| 80 | # test truth of regexps |
| 81 | is not(${qr//}), "", 'dereferenced regexps are true'; |
| 82 | |
| 83 | # not’s return value should be read-only, as it is the same global scalar |
| 84 | # each time (and test that it is, too). |
| 85 | *yes = \not 0; |
| 86 | *no = \not 1; |
| 87 | for (!0) { eval { $_ = 43 } } |
| 88 | like $@, qr/^Modification of a read-only value attempted at /, |
| 89 | 'not 0 is read-only'; |
| 90 | for (!1) { eval { $_ = 43 } } |
| 91 | like $@, qr/^Modification of a read-only value attempted at /, |
| 92 | 'not 1 is read-only'; |
| 93 | require Config; |
| 94 | is \!0, \$yes, '!0 returns the same value each time [perl #114838]'; |
| 95 | is \!1, \$no, '!1 returns the same value each time [perl #114838]'; |