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iEval git - pod-constants.git/blob - lib/Pod/Constants.pm
1 # Copyright (C) 2001, 2002, 2007 Sam Vilain. All Rights Reserved.
2 # This module is free software. It may be used, redistributed and/or
3 # modified under the terms of the Perl Artistic License, version 2 or
4 # later, OR the terms of the GNU General Public License, v3 or later.
6 package Pod
::Constants
;
12 use base
qw(Pod::Parser Exporter);
17 # An ugly hack to go from caller() to the relevant parser state
22 #my ($parser, $command, $paragraph, $line_num) = (@_);
25 return unless $parser->{active
};
27 print "Found end of $parser->{active}\n" if $parser->{DEBUG
};
28 my $whereto = $parser->{wanted_pod_tags
}->{$parser->{active
}};
29 print "\$_ will be set to:\n---\n$parser->{paragraphs}\n---\n" if $parser->{DEBUG
};
31 $parser->{paragraphs
} =~ s/^\s*|\s*$//gs if $parser->{trimmed_tags
}->{$parser->{active
}};
33 if (ref $whereto eq "CODE") {
34 print "calling sub\n" if $parser->{DEBUG
};
35 local ($_) = $parser->{paragraphs
};
37 print "done\n" if $parser->{DEBUG
};
38 } elsif (ref $whereto eq "SCALAR") {
39 print "inserting into scalar\n" if $parser->{DEBUG
};
40 $$whereto = $parser->{paragraphs
};
41 } elsif (ref $whereto eq "ARRAY") {
42 print "inserting into array\n" if $parser->{DEBUG
};
43 @
$whereto = split /\n/, $parser->{paragraphs
};
44 } elsif (ref $whereto eq "HASH") {
45 print "inserting into hash\n" if $parser->{DEBUG
};
46 # Oh, sorry, should I be in LISP101?
48 map { map { s/^\s*|\s*$//g; $_ } split /=>/, $_ } grep m
/^
49 ( (?
:[^=]|=[^>])+ ) # scan up to "=>"
51 ( (?
:[^=]|=[^>])+ =?
)# don't allow more "=>"'s
52 $/x, split /\n/, $parser->{paragraphs
});
53 } else { die $whereto }
54 $parser->{active
} = undef;
57 # Pod::Parser overloaded command
59 my ($parser, $command, $paragraph, $line_num) = @_;
61 $paragraph =~ s/(?:\r\n|\n\r)/\n/g;
63 print "Got command =$command, value=$paragraph\n" if $parser->{DEBUG
};
65 $parser->end_input() if $parser->{active
};
68 # first check for a catch-all for this command type
69 if ( exists $parser->{wanted_pod_tags
}->{"*$command"} ) {
70 $parser->{paragraphs
} = $paragraph;
71 $parser->{active
} = "*$command";
72 } elsif ($command =~ m/^(head\d+|item|(for|begin))$/) {
74 # if it's a "for" or "begin" section, the title is the
76 ($lookup, $parser->{paragraphs
}) = $paragraph =~ m/^\s*(\S*)\s*(.*)/s;
78 # otherwise, it's up to the end of the line
79 ($lookup, $parser->{paragraphs
}) = $paragraph =~ m/^\s*(\S[^\n]*?)\s*\n(.*)$/s;
82 # Look for a match by name
83 if (defined $lookup && exists $parser->{wanted_pod_tags
}->{$lookup}) {
84 print "Found $lookup\n" if ($parser->{DEBUG
});
85 $parser->{active
} = $lookup;
86 } elsif ($parser->{DEBUG
}) {
88 print "Ignoring =$command $paragraph (lookup = $lookup)\n"
93 print "Ignoring =$command (not known)\n" if $parser->{DEBUG
};
97 # Pod::Parser overloaded verbatim
99 my ($parser, $paragraph, $line_num) = @_;
100 $paragraph =~ s/(?:\r\n|\n\r)/\n/g;
102 my $status = $parser->{active
} ?
"using" : "ignoring";
103 print "Got paragraph: $paragraph ($status)\n" if $parser->{DEBUG
};
105 $parser->{paragraphs
} .= $paragraph if defined $parser->{active
}
108 # Pod::Parser overloaded textblock
109 sub textblock
{ goto \
&verbatim
}
114 # if no args, just return
117 # try to guess the source file of the caller
119 if (caller ne "main") {
120 (my $module = caller().".pm") =~ s
|::|/|g
;
121 $source_file = $INC{$module};
125 croak
"Cannot find source file (guessed $source_file) for package ".caller unless -f
$source_file;
127 # nasty tricks with the stack so we don't have to be silly with
129 unshift @_, $source_file;
130 goto \
&import_from_file
;
135 sub import_from_file
{
136 my $filename = shift;
138 my $parser = __PACKAGE__
->new();
140 $parser->{wanted_pod_tags
} = {};
141 $parser->{trimmed_tags
} = {};
142 $parser->{trim_next
} = 0;
143 $parser->{DEBUG
} = 0;
144 $parser->{active
} = undef;
145 $parsers{caller()} = $parser;
147 $parser->add_hook(@_);
149 print "Pod::Parser: DEBUG: Opening $filename for reading\n" if $parser->{DEBUG
};
150 my $fh = new IO
::Handle
;
151 open $fh, "<$filename" or die "cannot open $filename for reading; $!";
153 $parser->parse_from_filehandle($fh, \
*STDOUT
);
160 if (UNIVERSAL
::isa
($_[0], __PACKAGE__
)) {
163 $parser = $parsers{caller()} or die "add_hook called, but don't know what for - caller = ".caller;
165 while (my ($pod_tag, $var) = splice @_, 0, 2) {
166 #print "$pod_tag: $var\n";
167 if (lc($pod_tag) eq "-trim") {
168 $parser->{trim_next
} = $var;
169 } elsif ( lc($pod_tag) eq "-debug" ) {
170 $parser->{DEBUG
} = $var;
171 } elsif (lc($pod_tag) eq "-usage") {
172 # an idea for later - automatic "usage"
173 #%wanted_pod_tags{@tags}
175 if ((ref $var) =~ /^(?:SCALAR|CODE|ARRAY|HASH)$/) {
176 print "Will look for $pod_tag.\n" if $parser->{DEBUG
};
177 $parser->{wanted_pod_tags
}->{$pod_tag} = $var;
178 $parser->{trimmed_tags
}->{$pod_tag} = 1 if $parser->{trim_next
};
180 die "Sorry - need a reference to import POD sections into, not the scalar value $var"
188 if ( UNIVERSAL
::isa
($_[0], __PACKAGE__
) ) {
191 $parser = $parsers{caller()} or die "delete_hook called, but don't know what for - caller = ".caller;
193 while ( my $label = shift ) {
194 delete $parser->{wanted_pod_tags
}->{$label};
195 delete $parser->{trimmed_tags
}->{$label};
206 Pod::Constants - Include constants from POD
210 our ($myvar, $VERSION, @myarray, $html, %myhash);
212 use Pod::Constants -trim => 1,
213 'Pod Section Name' => \$myvar,
214 'Version' => sub { eval },
215 'Some list' => \@myarray,
217 'Some hash' => \%myhash;
219 =head2 Pod Section Name
221 This string will be loaded into $myvar
225 # This is an example of using a closure. $_ is set to the
226 # contents of the paragraph. In this example, "eval" is
227 # used to execute this code at run time.
232 Each line from this section of the file
233 will be placed into a separate array element.
234 For example, this is $myarray[2].
238 This text will not go into the hash, because
239 it doesn't look like a definition list.
240 key1 => Some value (this will go into the hash)
241 var2 => Some Other value (so will this)
242 wtf = This won't make it in.
244 =head2 %myhash's value after the above:
246 ( key1 => "Some value (this will go into the hash)",
247 var2 => "Some Other value (so will this)" )
249 =begin html <p>This text will be in $html</p>
255 This module allows you to specify those constants that should be
256 documented in your POD, and pull them out a run time in a fairly
259 Pod::Constants uses Pod::Parser to do the parsing of the source file.
260 It has to open the source file it is called from, and does so directly
261 either by lookup in %INC or by assuming it is $0 if the caller is
262 "main" (or it can't find %INC{caller()})
264 =head2 ARBITARY DECISIONS
266 I have made this code only allow the "Pod Section Name" to match
267 `headN', `item', `for' and `begin' POD sections. If you have a good
268 reason why you think it should match other POD sections, drop me a
269 line and if I'm convinced I'll put it in the standard version.
271 For `for' and `begin' sections, only the first word is counted as
272 being a part of the specifier, as opposed to `headN' and `item', where
273 the entire rest of the line counts.
279 This function is called when we are "use"'d. It determines the source
280 file by inspecting the value of caller() or $0.
282 The form of @args is HOOK => $where.
284 $where may be a scalar reference, in which case the contents of the
285 POD section called "HOOK" will be loaded into $where.
287 $where may be an array reference, in which case the contents of the
288 array will be the contents of the POD section called "HOOK", split
291 $where may be a hash reference, in which case any lines with a "=>"
292 symbol present will have everything on the left have side of the =>
293 operator as keys and everything on the right as values. You do not
294 need to quote either, nor have trailing commas at the end of the
297 $where may be a code reference (sub { }), in which case the sub is
298 called when the hook is encountered. $_ is set to the value of the
301 You may also specify the behaviour of whitespace trimming; by default,
302 no trimming is done except on the HOOK names. Setting "-trim => 1"
303 turns on a package "global" (until the next time import is called)
304 that will trim the $_ sent for processing by the hook processing
305 function (be it a given function, or the built-in array/hash
306 splitters) for leading and trailing whitespace.
308 The name of HOOK is matched against any "=head1", "=head2", "=item",
309 "=for", "=begin" value. If you specify the special hooknames "*item",
310 "*head1", etc, then you will get a function that is run for every
312 Note that the supplied functions for array and hash splitting are
313 exactly equivalent to fairly simple Perl blocks:
317 HOOK => sub { @array = split /\n/, $_ }
323 (map { map { s/^\s+|\s+$//g; $_ } split /=>/, $_ }
325 ( (?:[^=]|=[^>])+ ) # scan up to "=>"
327 ( (?:[^=]|=[^>])+ =? )# don't allow more "=>"'s
328 $/x, split /\n/, $_));
331 Well, they're simple if you can grok map, a regular expression like
332 that and a functional programming style. If you can't I'm sure it is
333 probably voodoo to you.
335 Here's the procedural equivalent:
338 for my $line (split /\n/, $_) {
339 my ($key, $value, $junk) = split /=>/, $line;
341 $key =~ s/^\s+|\s+$//g
342 $value =~ s/^\s+|\s+$//g
343 $hash{$key} = $value;
347 =head2 import_from_file($filename, @args)
349 Very similar to straight "import", but you specify the source filename
352 =head2 add_hook(NAME => value)
354 This function adds another hook, it is useful for dynamic updating of
355 parsing through the document.
357 For an example, please see t/01-constants.t in the source
358 distribution. More detailed examples will be added in a later
361 =head2 delete_hook(@list)
363 Deletes the named hooks. Companion function to add_hook
365 =head2 CLOSURES AS DESTINATIONS
367 If the given value is a ref CODE, then that function is called, with
368 $_ set to the value of the paragraph. This can be very useful for
369 applying your own custom mutations to the POD to change it from human
370 readable text into something your program can use.
372 After I added this function, I just kept on thinking of cool uses for
373 it. The nice, succinct code you can make with it is one of
374 Pod::Constant's strongest features.
376 Below are some examples.
380 =head2 Module Makefile.PL maintenance
382 Tired of keeping those module Makefile.PL's up to date? Note: This
383 method seems to break dh-make-perl.
385 =head2 Example Makefile.PL
387 eval "use Pod::Constants";
388 ($Pod::Constants::VERSION >= 0.11)
391 #### ERROR: This module requires Pod::Constants 0.11 or
392 #### higher to be installed.
396 my ($VERSION, $NAME, $PREREQ_PM, $ABSTRACT, $AUTHOR);
397 Pod::Constants::import_from_file
400 'MODULE RELEASE' => sub { ($VERSION) = m/(\d+\.\d+)/ },
401 'DEPENDENCIES' => ($PREREQ_PM = { }),
403 'NAME' => sub { $ABSTRACT=$_; ($NAME) = m/(\S+)/ },
404 'AUTHOR' => \$AUTHOR,
410 'PREREQ_PM' => $PREREQ_PM,
411 'VERSION' => $VERSION,
412 ($] >= 5.005 ? ## Add these new keywords supported since 5.005
413 (ABSTRACT => $ABSTRACT,
414 AUTHOR => $AUTHOR) : ()),
417 =head2 Corresponding Module
421 MyTestModule - Demonstrate Pod::Constant's Makefile.PL usefulness
423 =head2 MODULE RELEASE
425 This is release 1.05 of this module.
429 The following modules are required to make this module:
435 Ima Twat <ima@twat.name>
440 use Pod::Constants -trim => 1,
441 'MODULE RELEASE' => sub { ($VERSION) = m/(\d+\.\d+) or die };
445 Sam Vilain, <samv@cpan.org>
449 I keep thinking it would be nice to be able to import an =item list
450 into an array or something, eg for a program argument list. But I'm
451 not too sure how it would be all that useful in practice; you'd end up
452 putting the function names for callbacks in the pod or something
453 (perhaps not all that bad).
455 Would this be useful?
457 Pod::Constants::import(Foo::SECTION => \$myvar);
459 Debug output is not very readable
461 =head1 PATCHES WELCOME
463 If you have any suggestions for enhancements, they are much more likely
464 to happen if you submit them as a patch to the distribution.
468 git://utsl.gen.nz/Pod-Constants
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