package vars;
+use 5.006;
+
+our $VERSION = '1.01';
+
+use warnings::register;
+use strict qw(vars subs);
+
+sub import {
+ my $callpack = caller;
+ my ($pack, @imports) = @_;
+ my ($sym, $ch);
+ foreach (@imports) {
+ if (($ch, $sym) = /^([\$\@\%\*\&])(.+)/) {
+ if ($sym =~ /\W/) {
+ # time for a more-detailed check-up
+ if ($sym =~ /^\w+[[{].*[]}]$/) {
+ require Carp;
+ Carp::croak("Can't declare individual elements of hash or array");
+ } elsif (warnings::enabled() and length($sym) == 1 and $sym !~ tr/a-zA-Z//) {
+ warnings::warn("No need to declare built-in vars");
+ } elsif (($^H &= strict::bits('vars'))) {
+ require Carp;
+ Carp::croak("'$_' is not a valid variable name under strict vars");
+ }
+ }
+ $sym = "${callpack}::$sym" unless $sym =~ /::/;
+ *$sym =
+ ( $ch eq "\$" ? \$$sym
+ : $ch eq "\@" ? \@$sym
+ : $ch eq "\%" ? \%$sym
+ : $ch eq "\*" ? \*$sym
+ : $ch eq "\&" ? \&$sym
+ : do {
+ require Carp;
+ Carp::croak("'$_' is not a valid variable name");
+ });
+ } else {
+ require Carp;
+ Carp::croak("'$_' is not a valid variable name");
+ }
+ }
+};
+
+1;
+__END__
+
=head1 NAME
-vars - Perl pragma to predeclare global variable names
+vars - Perl pragma to predeclare global variable names (obsolete)
=head1 SYNOPSIS
=head1 DESCRIPTION
+NOTE: For variables in the current package, the functionality provided
+by this pragma has been superseded by C<our> declarations, available
+in Perl v5.6.0 or later. See L<perlfunc/our>.
+
This will predeclare all the variables whose names are
in the list, allowing you to use them under "use strict", and
disabling any typo warnings.
-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.
+Unlike pragmas that affect the C<$^H> hints variable, the C<use vars> and
+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>.
-See L<perlmod/Pragmatic Modules>.
+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.
-=cut
-require 5.000;
-use Carp;
+See L<perlmodlib/Pragmatic Modules>.
-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;
+=cut