X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2Fvars.pm;h=ca2a08dcf6c9572fa1936cd26cfaf9a3bb79f39f;hb=71ad7795db6b8d545a629fdaf0efbb677f2f2921;hp=0b7dacc7511fe59a921e4fc42463ad792f1e5222;hpb=3561ff8967661c363e907527e81e69a79a1e4ef2;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/lib/vars.pm b/lib/vars.pm
index 0b7dacc..ca2a08d 100644
--- a/lib/vars.pm
+++ b/lib/vars.pm
@@ -1,5 +1,48 @@
 package vars;
 
+require 5.002;
+
+# The following require can't be removed during maintenance
+# releases, sadly, because of the risk of buggy code that does
+# require Carp; Carp::croak "..."; without brackets dying
+# if Carp hasn't been loaded in earlier compile time. :-(
+# We'll let those bugs get found on the development track.
+require Carp if $] < 5.00450;
+
+sub import {
+    my $callpack = caller;
+    my ($pack, @imports, $sym, $ch) = @_;
+    foreach $sym (@imports) {
+        ($ch, $sym) = unpack('a1a*', $sym);
+	if ($sym =~ tr/A-Za-z_0-9//c) {
+	    # time for a more-detailed check-up
+	    if ($sym =~ /::/) {
+		require Carp;
+		Carp::croak("Can't declare another package's variables");
+	    } elsif ($sym =~ /^\w+[[{].*[]}]$/) {
+		require Carp;
+		Carp::croak("Can't declare individual elements of hash or array");
+	    } elsif ($^W and length($sym) == 1 and $sym !~ tr/a-zA-Z//) {
+		require Carp;
+		Carp::carp("No need to declare built-in vars");
+	    }
+	}
+        *{"${callpack}::$sym"} =
+          (  $ch eq "\$" ? \$   {"${callpack}::$sym"}
+           : $ch eq "\@" ? \@   {"${callpack}::$sym"}
+           : $ch eq "\%" ? \%   {"${callpack}::$sym"}
+           : $ch eq "\*" ? \*   {"${callpack}::$sym"}
+           : $ch eq "\&" ? \&   {"${callpack}::$sym"}
+           : do {
+		require Carp;
+		Carp::croak("'$ch$sym' is not a valid variable name");
+	     });
+    }
+};
+
+1;
+__END__
+
 =head1 NAME
 
 vars - Perl pragma to predeclare global variable names
@@ -19,34 +62,14 @@ C<use subs> declarations are not BLOCK-scoped.  They are thus effective
 for the entire file in which they appear.  You may not rescind such
 declarations with C<no vars> or C<no subs>.
 
-Packages such as the B<AutoLoader> and B<SelfLoader> that delay loading
-of subroutines within packages can create problems with package lexicals
-defined using C<my()>. While the B<vars> pragma cannot duplicate the
-effect of package lexicals (total transparency outside of the package),
-it can act as an acceptable substitute by pre-declaring global symbols,
-ensuring their availability to to the later-loaded routines.
+Packages such as the B<AutoLoader> and B<SelfLoader> that delay
+loading of subroutines within packages can create problems with
+package lexicals defined using C<my()>. While the B<vars> pragma
+cannot duplicate the effect of package lexicals (total transparency
+outside of the package), it can act as an acceptable substitute by
+pre-declaring global symbols, ensuring their availability to the
+later-loaded routines.
 
-See L<perlmod/Pragmatic Modules>.
+See L<perlmodlib/Pragmatic Modules>.
 
 =cut
-
-require 5.002;
-use Carp;
-
-sub import {
-    my $callpack = caller;
-    my ($pack, @imports, $sym, $ch) = @_;
-    foreach $sym (@imports) {
-	croak "Can't declare another package's variables" if $sym =~ /::/;
-        ($ch, $sym) = unpack('a1a*', $sym);
-        *{"${callpack}::$sym"} =
-          (  $ch eq "\$" ? \$   {"${callpack}::$sym"}
-           : $ch eq "\@" ? \@   {"${callpack}::$sym"}
-           : $ch eq "\%" ? \%   {"${callpack}::$sym"}
-           : $ch eq "\*" ? \*   {"${callpack}::$sym"}
-           : $ch eq "\&" ? \&   {"${callpack}::$sym"}
-           : croak "'$ch$sym' is not a valid variable name\n");
-    }
-};
-
-1;