X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2Fstrict.pm;h=8afb9a37921c13127577a5cd8e129517b58bc46d;hb=92dffb52e8549d6a194db47a2e5b989b8338a19a;hp=a1c51531e9711c1fb94c2c1c26ab798df24fc7fd;hpb=4a2eeee972073f14f452b0d672c9d9c9ad2d6463;p=p5sagit%2Fp5-mst-13.2.git diff --git a/lib/strict.pm b/lib/strict.pm index a1c5153..8afb9a3 100644 --- a/lib/strict.pm +++ b/lib/strict.pm @@ -11,7 +11,6 @@ strict - Perl pragma to restrict unsafe constructs use strict "vars"; use strict "refs"; use strict "subs"; - use strict "untie"; use strict; no strict "vars"; @@ -20,8 +19,8 @@ strict - Perl pragma to restrict unsafe constructs If no import list is supplied, all possible restrictions are assumed. (This is the safest mode to operate in, but is sometimes too strict for -casual programming.) Currently, there are four possible things to be -strict about: "subs", "vars", "refs", and "untie". +casual programming.) Currently, there are three possible things to be +strict about: "subs", "vars", and "refs". =over 6 @@ -35,11 +34,22 @@ use symbolic references (see L). print $$ref; # ok $ref = "foo"; print $$ref; # runtime error; normally ok + $file = "STDOUT"; + print $file "Hi!"; # error; note: no comma after $file + +There is one exception to this rule: + + $bar = \&{'foo'}; + &$bar; + +is allowed so that C would not break under stricture. + =item C This generates a compile-time error if you access a variable that wasn't -localized via C or wasn't fully qualified. Because this is to avoid +declared via "our" or C, +localized via C, or wasn't fully qualified. Because this is to avoid variable suicide problems and subtle dynamic scoping issues, a merely local() variable isn't good enough. See L and L. @@ -49,14 +59,21 @@ L. my $foo = 10; # ok, my() var local $foo = 9; # blows up + package Cinna; + our $bar; # Declares $bar in current package + $bar = 'HgS'; # ok, global declared via pragma + The local() generated a compile-time error because you just touched a global name without fully qualifying it. +Because of their special use by sort(), the variables $a and $b are +exempted from this check. + =item C This disables the poetry optimization, generating a compile-time error if you try to use a bareword identifier that's not a subroutine, unless it -appears in curly braces or on the left hand side of the "=>" symbol. +appears in curly braces or on the left hand side of the "=E" symbol. use strict 'subs'; @@ -66,50 +83,35 @@ appears in curly braces or on the left hand side of the "=>" symbol. -=item C - -This generates a runtime error if any references to the object returned -by C (or C) still exist when C is called. Note that -to get this strict behaviour, the C statement must -be in the same scope as the C. See L, -L, L and L. - - use strict 'untie'; - $a = tie %a, 'SOME_PKG'; - $b = tie %b, 'SOME_PKG'; - $b = 0; - tie %c, PKG; - $c = tied %c; - untie %a ; # blows up, $a is a valid object reference. - untie %b; # ok, $b is not a reference to the object. - untie %c ; # blows up, $c is a valid object reference. - =back -See L. +See L. =cut +$strict::VERSION = "1.01"; + +my %bitmask = ( +refs => 0x00000002, +subs => 0x00000200, +vars => 0x00000400 +); + sub bits { my $bits = 0; - foreach $sememe (@_) { - $bits |= 0x00000002 if $sememe eq 'refs'; - $bits |= 0x00000200 if $sememe eq 'subs'; - $bits |= 0x00000400 if $sememe eq 'vars'; - $bits |= 0x00000800 if $sememe eq 'untie'; - } + foreach my $s (@_){ $bits |= $bitmask{$s} || 0; }; $bits; } sub import { shift; - $^H |= bits(@_ ? @_ : qw(refs subs vars untie)); + $^H |= bits(@_ ? @_ : qw(refs subs vars)); } sub unimport { shift; - $^H &= ~ bits(@_ ? @_ : qw(refs subs vars untie)); + $^H &= ~ bits(@_ ? @_ : qw(refs subs vars)); } 1;