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60 | by this pragma has been superseded by C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