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1 | |
2 | require 5; |
3 | package Pod::Simple::Debug; |
4 | use strict; |
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5 | use vars qw($VERSION ); |
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6 | $VERSION = '3.14'; |
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7 | |
8 | sub import { |
9 | my($value,$variable); |
10 | |
11 | if(@_ == 2) { |
12 | $value = $_[1]; |
13 | } elsif(@_ == 3) { |
14 | ($variable, $value) = @_[1,2]; |
15 | |
16 | ($variable, $value) = ($value, $variable) |
17 | if defined $value and ref($value) eq 'SCALAR' |
18 | and not(defined $variable and ref($variable) eq 'SCALAR') |
19 | ; # tolerate getting it backwards |
20 | |
21 | unless( defined $variable and ref($variable) eq 'SCALAR') { |
22 | require Carp; |
23 | Carp::croak("Usage:\n use Pod::Simple::Debug (NUMVAL)\nor" |
24 | . "\n use Pod::Simple::Debug (\\\$var, STARTNUMVAL)\nAborting"); |
25 | } |
26 | } else { |
27 | require Carp; |
28 | Carp::croak("Usage:\n use Pod::Simple::Debug (NUMVAL)\nor" |
29 | . "\n use Pod::Simple::Debug (\\\$var, STARTNUMVAL)\nAborting"); |
30 | } |
31 | |
32 | if( defined &Pod::Simple::DEBUG ) { |
33 | require Carp; |
34 | Carp::croak("It's too late to call Pod::Simple::Debug -- " |
35 | . "Pod::Simple has already loaded\nAborting"); |
36 | } |
37 | |
38 | $value = 0 unless defined $value; |
39 | |
40 | unless($value =~ m/^-?\d+$/) { |
41 | require Carp; |
42 | Carp::croak( "$value isn't a numeric value." |
43 | . "\nUsage:\n use Pod::Simple::Debug (NUMVAL)\nor" |
44 | . "\n use Pod::Simple::Debug (\\\$var, STARTNUMVAL)\nAborting"); |
45 | } |
46 | |
47 | if( defined $variable ) { |
48 | # make a not-really-constant |
49 | *Pod::Simple::DEBUG = sub () { $$variable } ; |
50 | $$variable = $value; |
51 | print "# Starting Pod::Simple::DEBUG = non-constant $variable with val $value\n"; |
52 | } else { |
53 | *Pod::Simple::DEBUG = eval " sub () { $value } "; |
54 | print "# Starting Pod::Simple::DEBUG = $value\n"; |
55 | } |
56 | |
57 | require Pod::Simple; |
58 | return; |
59 | } |
60 | |
61 | 1; |
62 | |
63 | |
64 | __END__ |
65 | |
66 | =head1 NAME |
67 | |
68 | Pod::Simple::Debug -- put Pod::Simple into trace/debug mode |
69 | |
70 | =head1 SYNOPSIS |
71 | |
72 | use Pod::Simple::Debug (5); # or some integer |
73 | |
74 | Or: |
75 | |
76 | my $debuglevel; |
77 | use Pod::Simple::Debug (\$debuglevel, 0); |
78 | ...some stuff that uses Pod::Simple to do stuff, but which |
79 | you don't want debug output from... |
80 | |
81 | $debug_level = 4; |
82 | ...some stuff that uses Pod::Simple to do stuff, but which |
83 | you DO want debug output from... |
84 | |
85 | $debug_level = 0; |
86 | |
87 | =head1 DESCRIPTION |
88 | |
89 | This is an internal module for controlling the debug level (a.k.a. trace |
90 | level) of Pod::Simple. This is of interest only to Pod::Simple |
91 | developers. |
92 | |
93 | |
94 | =head1 CAVEATS |
95 | |
96 | Note that you should load this module I<before> loading Pod::Simple (or |
97 | any Pod::Simple-based class). If you try loading Pod::Simple::Debug |
98 | after &Pod::Simple::DEBUG is already defined, Pod::Simple::Debug will |
99 | throw a fatal error to the effect that |
100 | "it's s too late to call Pod::Simple::Debug". |
101 | |
102 | Note that the C<use Pod::Simple::Debug (\$x, I<somenum>)> mode will make |
103 | Pod::Simple (et al) run rather slower, since &Pod::Simple::DEBUG won't |
104 | be a constant sub anymore, and so Pod::Simple (et al) won't compile with |
105 | constant-folding. |
106 | |
107 | |
108 | =head1 GUTS |
109 | |
110 | Doing this: |
111 | |
112 | use Pod::Simple::Debug (5); # or some integer |
113 | |
114 | is basically equivalent to: |
115 | |
116 | BEGIN { sub Pod::Simple::DEBUG () {5} } # or some integer |
117 | use Pod::Simple (); |
118 | |
119 | And this: |
120 | |
121 | use Pod::Simple::Debug (\$debug_level,0); # or some integer |
122 | |
123 | is basically equivalent to this: |
124 | |
125 | my $debug_level; |
126 | BEGIN { $debug_level = 0 } |
127 | BEGIN { sub Pod::Simple::DEBUG () { $debug_level } |
128 | use Pod::Simple (); |
129 | |
130 | =head1 SEE ALSO |
131 | |
132 | L<Pod::Simple> |
133 | |
134 | The article "Constants in Perl", in I<The Perl Journal> issue |
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135 | 21. See L<http://interglacial.com/tpj/21/> |
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136 | |
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137 | =head1 SUPPORT |
138 | |
139 | Questions or discussion about POD and Pod::Simple should be sent to the |
140 | pod-people@perl.org mail list. Send an empty email to |
141 | pod-people-subscribe@perl.org to subscribe. |
142 | |
143 | This module is managed in an open GitHub repository, |
144 | L<http://github.com/theory/pod-simple/>. Feel free to fork and contribute, or |
145 | to clone L<git://github.com/theory/pod-simple.git> and send patches! |
146 | |
147 | Patches against Pod::Simple are welcome. Please send bug reports to |
148 | <bug-pod-simple@rt.cpan.org>. |
149 | |
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150 | =head1 COPYRIGHT AND DISCLAIMERS |
151 | |
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152 | Copyright (c) 2002 Sean M. Burke. |
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153 | |
154 | This library is free software; you can redistribute it and/or modify it |
155 | under the same terms as Perl itself. |
156 | |
157 | This program is distributed in the hope that it will be useful, but |
158 | without any warranty; without even the implied warranty of |
159 | merchantability or fitness for a particular purpose. |
160 | |
161 | =head1 AUTHOR |
162 | |
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163 | Pod::Simple was created by Sean M. Burke <sburke@cpan.org>. |
164 | But don't bother him, he's retired. |
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165 | |
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166 | Pod::Simple is maintained by: |
167 | |
168 | =over |
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169 | |
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170 | =item * Allison Randal C<allison@perl.org> |
171 | |
172 | =item * Hans Dieter Pearcey C<hdp@cpan.org> |
173 | |
174 | =item * David E. Wheeler C<dwheeler@cpan.org> |
175 | |
176 | =back |
177 | |
178 | =cut |