| package vars; |
| |
| use 5.006; |
| |
| our $VERSION = '1.02'; |
| |
| use warnings::register; |
| use strict qw(vars subs); |
| |
| sub import { |
| my $callpack = caller; |
| my (undef, @imports) = @_; |
| my ($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 (obsolete) |
| |
| =head1 SYNOPSIS |
| |
| use vars qw($frob @mung %seen); |
| |
| =head1 DESCRIPTION |
| |
| NOTE: For variables in the current package, the functionality provided |
| by this pragma has been superseded by C<our> declarations, available |
| in Perl v5.6.0 or later. See L<perlfunc/our>. |
| |
| This will predeclare all the variables whose names are |
| in the list, allowing you to use them under "use strict", and |
| disabling any typo warnings. |
| |
| Unlike pragmas that affect the C<$^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 |