| 1 | package vars;
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| 2 |
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| 3 | use 5.006;
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| 4 |
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| 5 | our $VERSION = '1.01';
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| 6 |
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| 7 | use warnings::register;
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| 8 | use strict qw(vars subs);
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| 9 |
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| 10 | sub import {
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| 11 | my $callpack = caller;
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| 12 | my ($pack, @imports) = @_;
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| 13 | my ($sym, $ch);
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| 14 | foreach (@imports) {
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| 15 | if (($ch, $sym) = /^([\$\@\%\*\&])(.+)/) {
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| 16 | if ($sym =~ /\W/) {
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| 17 | # time for a more-detailed check-up
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| 18 | if ($sym =~ /^\w+[[{].*[]}]$/) {
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| 19 | require Carp;
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| 20 | Carp::croak("Can't declare individual elements of hash or array");
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| 21 | } elsif (warnings::enabled() and length($sym) == 1 and $sym !~ tr/a-zA-Z//) {
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| 22 | warnings::warn("No need to declare built-in vars");
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| 23 | } elsif (($^H &= strict::bits('vars'))) {
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| 24 | require Carp;
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| 25 | Carp::croak("'$_' is not a valid variable name under strict vars");
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| 26 | }
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| 27 | }
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| 28 | $sym = "${callpack}::$sym" unless $sym =~ /::/;
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| 29 | *$sym =
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| 30 | ( $ch eq "\$" ? \$$sym
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| 31 | : $ch eq "\@" ? \@$sym
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| 32 | : $ch eq "\%" ? \%$sym
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| 33 | : $ch eq "\*" ? \*$sym
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| 34 | : $ch eq "\&" ? \&$sym
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| 35 | : do {
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| 36 | require Carp;
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| 37 | Carp::croak("'$_' is not a valid variable name");
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| 38 | });
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| 39 | } else {
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| 40 | require Carp;
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| 41 | Carp::croak("'$_' is not a valid variable name");
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| 42 | }
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| 43 | }
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| 44 | };
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| 45 |
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| 46 | 1;
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| 47 | __END__
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| 48 |
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| 49 | =head1 NAME
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| 50 |
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| 51 | vars - Perl pragma to predeclare global variable names (obsolete)
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| 52 |
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| 53 | =head1 SYNOPSIS
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| 54 |
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| 55 | use vars qw($frob @mung %seen);
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| 56 |
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| 57 | =head1 DESCRIPTION
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| 58 |
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| 59 | NOTE: For variables in the current package, the functionality provided
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| 60 | by this pragma has been superseded by C<our> declarations, available
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| 61 | in Perl v5.6.0 or later. See L<perlfunc/our>.
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| 62 |
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| 63 | This will predeclare all the variables whose names are
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| 64 | in the list, allowing you to use them under "use strict", and
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| 65 | disabling any typo warnings.
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| 66 |
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| 67 | Unlike pragmas that affect the C<$^H> hints variable, the C<use vars> and
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| 68 | C<use subs> declarations are not BLOCK-scoped. They are thus effective
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| 69 | for the entire file in which they appear. You may not rescind such
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| 70 | declarations with C<no vars> or C<no subs>.
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| 71 |
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| 72 | Packages such as the B<AutoLoader> and B<SelfLoader> that delay
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| 73 | loading of subroutines within packages can create problems with
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| 74 | package lexicals defined using C<my()>. While the B<vars> pragma
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| 75 | cannot duplicate the effect of package lexicals (total transparency
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| 76 | outside of the package), it can act as an acceptable substitute by
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| 77 | pre-declaring global symbols, ensuring their availability to the
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| 78 | later-loaded routines.
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| 79 |
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| 80 | See L<perlmodlib/Pragmatic Modules>.
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| 81 |
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| 82 | =cut
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