X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2Fstrict.pm;h=d1479ed865ee1dd4c627f6d08ec90728f628c70c;hb=11412ee612ee855f6157e78034024e8f5e3ba052;hp=d35c6c105c1be3d22701af0f463bbd8f4a0c8036;hpb=f06db76b9e41859439aeadb79feb6c603ee741ff;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/lib/strict.pm b/lib/strict.pm
index d35c6c1..d1479ed 100644
--- a/lib/strict.pm
+++ b/lib/strict.pm
@@ -1,5 +1,40 @@
 package strict;
 
+$strict::VERSION = "1.02";
+
+my %bitmask = (
+refs => 0x00000002,
+subs => 0x00000200,
+vars => 0x00000400
+);
+
+sub bits {
+    my $bits = 0;
+    my @wrong;
+    foreach my $s (@_) {
+	push @wrong, $s unless exists $bitmask{$s};
+        $bits |= $bitmask{$s} || 0;
+    }
+    if (@wrong) {
+        require Carp;
+        Carp::croak("Unknown 'strict' tag(s) '@wrong'");
+    }
+    $bits;
+}
+
+sub import {
+    shift;
+    $^H |= bits(@_ ? @_ : qw(refs subs vars));
+}
+
+sub unimport {
+    shift;
+    $^H &= ~ bits(@_ ? @_ : qw(refs subs vars));
+}
+
+1;
+__END__
+
 =head1 NAME
 
 strict - Perl pragma to restrict unsafe constructs
@@ -34,11 +69,22 @@ use symbolic references (see L<perlref>).
     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<goto &$AUTOLOAD> would not break under stricture.
+
 
 =item C<strict vars>
 
 This generates a compile-time error if you access a variable that wasn't
-localized via C<my()> or wasn't fully qualified.  Because this is to avoid
+declared via "our" or C<use vars>,
+localized via C<my()>, 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<perlfunc/my> and
 L<perlfunc/local>.
@@ -48,44 +94,32 @@ L<perlfunc/local>.
     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<strict subs>
 
-This disables the poetry optimization,
-generating a compile-time error if you 
-try to use a bareword identifier that's not a subroutine.
+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 "=E<gt>" symbol.
+
 
     use strict 'subs';
     $SIG{PIPE} = Plumber;   	# blows up
-    $SIG{"PIPE"} = "Plumber"; 	# just fine
-
-=back
-
-See L<perlmod/Pragmatic Modules>.
+    $SIG{PIPE} = "Plumber"; 	# just fine: bareword in curlies always ok
+    $SIG{PIPE} = \&Plumber; 	# preferred form
 
 
-=cut
-
-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;
-}
 
-sub import {
-    shift;
-    $^H |= bits(@_ ? @_ : qw(refs subs vars));
-}
+=back
 
-sub unimport {
-    shift;
-    $^H &= ~ bits(@_ ? @_ : qw(refs subs vars));
-}
+See L<perlmodlib/Pragmatic Modules>.
 
-1;
+=cut