80 lines
2.5 KiB
Perl
80 lines
2.5 KiB
Perl
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;
|
|
use warnings::register();
|
|
|
|
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+[[{].*[]}]$/) {
|
|
require Carp;
|
|
Carp::croak("Can't declare individual elements of hash or array");
|
|
} elsif (warnings::enabled() and length($sym) == 1 and $sym !~ tr/a-zA-Z//) {
|
|
warnings::warn("No need to declare built-in vars");
|
|
}
|
|
}
|
|
*{"${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$sym' is not a valid variable name");
|
|
});
|
|
}
|
|
};
|
|
|
|
1;
|
|
__END__
|
|
|
|
=head1 NAME
|
|
|
|
vars - Perl pragma to predeclare global variable names (obsolete)
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
use vars qw($frob @mung %seen);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
NOTE: The functionality provided by this pragma has been superseded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.
|
|
|
|
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>.
|
|
|
|
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<perlmodlib/Pragmatic Modules>.
|
|
|
|
=cut
|