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1=head1 NAME
2
3version - Perl extension for Version Objects
4
5=head1 SYNOPSIS
6
692a467c 7 # Parsing version strings (decimal or dotted-decimal)
cb5772bb 8
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9 use version 0.77; # get latest bug-fixes and API
10 $ver = version->parse($string)
cb5772bb 11
692a467c 12 # Declaring a dotted-decimal $VERSION (keep on one line!)
cb5772bb 13
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14 use version; our $VERSION = version->declare("v1.2.3"); # formal
15 use version; our $VERSION = qv("v1.2.3"); # shorthand
16 use version; our $VERSION = qv("v1.2_3"); # alpha
317f7c8a 17
692a467c 18 # Declaring an old-style decimal $VERSION (use quotes!)
317f7c8a 19
555bd962 20 our $VERSION = "1.0203"; # recommended
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21 use version; our $VERSION = version->parse("1.0203"); # formal
22 use version; our $VERSION = version->parse("1.02_03"); # alpha
317f7c8a 23
692a467c 24 # Comparing mixed version styles (decimals, dotted-decimals, objects)
317f7c8a 25
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26 if ( version->parse($v1) == version->parse($v2) ) {
27 # do stuff
28 }
317f7c8a 29
692a467c 30 # Sorting mixed version styles
317f7c8a 31
692a467c 32 @ordered = sort { version->parse($a) <=> version->parse($b) } @list;
317f7c8a 33
692a467c 34=head1 DESCRIPTION
317f7c8a 35
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36Version objects were added to Perl in 5.10. This module implements version
37objects for older version of Perl and provides the version object API for all
38versions of Perl. All previous releases before 0.74 are deprecated and should
39not be used due to incompatible API changes. Version 0.77 introduces the new
40'parse' and 'declare' methods to standardize usage. You are strongly urged to
61a0cb1c 41set 0.77 as a minimum in your code, e.g.
317f7c8a 42
692a467c 43 use version 0.77; # even for Perl v.5.10.0
cb5772bb 44
692a467c 45=head1 TYPES OF VERSION OBJECTS
cb5772bb 46
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47There are two different types of version objects, corresponding to the two
48different styles of versions in use:
cb5772bb 49
692a467c 50=over 2
cb5772bb 51
692a467c 52=item Decimal Versions
cb5772bb 53
692a467c 54The classic floating-point number $VERSION. The advantage to this style is
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55that you don't need to do anything special, just type a number into your
56source file. Quoting is recommended, as it ensures that trailing zeroes
57("1.50") are preserved in any warnings or other output.
cb5772bb 58
692a467c 59=item Dotted Decimal Versions
cb5772bb 60
692a467c 61The more modern form of version assignment, with 3 (or potentially more)
a8fb8d79 62integers separated by decimal points (e.g. v1.2.3). This is the form that
8c72d156 63Perl itself has used since 5.6.0 was released. The leading 'v' is now
692a467c 64strongly recommended for clarity, and will throw a warning in a future
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65release if omitted. A leading 'v' character is required to pass the
66L</is_strict()> test.
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67
68=back
69
692a467c 70=head1 DECLARING VERSIONS
43eaf59d 71
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72If you have a module that uses a decimal $VERSION (floating point), and you
73do not intend to ever change that, this module is not for you. There is
74nothing that version.pm gains you over a simple $VERSION assignment:
cb5772bb 75
6369c739 76 our $VERSION = "1.02";
cb5772bb 77
61a0cb1c 78Since Perl v5.10.0 includes the version.pm comparison logic anyways,
692a467c 79you don't need to do anything at all.
cb5772bb 80
692a467c 81=head2 How to convert a module from decimal to dotted-decimal
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83If you have used a decimal $VERSION in the past and wish to switch to a
84dotted-decimal $VERSION, then you need to make a one-time conversion to
61a0cb1c 85the new format.
cb5772bb 86
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87B<Important Note>: you must ensure that your new $VERSION is numerically
88greater than your current decimal $VERSION; this is not always obvious. First,
89convert your old decimal version (e.g. 1.02) to a normalized dotted-decimal
90form:
cb5772bb 91
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92 $ perl -Mversion -e 'print version->parse("1.02")->normal'
93 v1.20.0
cb5772bb 94
692a467c 95Then increment any of the dotted-decimal components (v1.20.1 or v1.21.0).
cb5772bb 96
692a467c 97=head2 How to C<declare()> a dotted-decimal version
cb5772bb 98
8c72d156 99 use version; our $VERSION = version->declare("v1.2.3");
cb5772bb 100
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101The C<declare()> method always creates dotted-decimal version objects. When
102used in a module, you B<must> put it on the same line as "use version" to
103ensure that $VERSION is read correctly by PAUSE and installer tools. You
104should also add 'version' to the 'configure_requires' section of your
105module metadata file. See instructions in L<ExtUtils::MakeMaker> or
106L<Module::Build> for details.
cb5772bb 107
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108B<Important Note>: Even if you pass in what looks like a decimal number
109("1.2"), a dotted-decimal will be created ("v1.200.0"). To avoid confusion
110or unintentional errors on older Perls, follow these guidelines:
cb5772bb 111
692a467c 112=over 2
cb5772bb 113
692a467c 114=item *
cb5772bb 115
692a467c 116Always use a dotted-decimal with (at least) three components
92dcf8ce 117
692a467c 118=item *
92dcf8ce 119
692a467c 120Always use a leading-v
92dcf8ce 121
692a467c 122=item *
92dcf8ce 123
692a467c 124Always quote the version
92dcf8ce 125
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126=back
127
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128If you really insist on using version.pm with an ordinary decimal version,
129use C<parse()> instead of declare. See the L<PARSING AND COMPARING VERSIONS>
130for details.
cb5772bb 131
6369c739 132See also L<version::Internals> for more on version number conversion,
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133quoting, calculated version numbers and declaring developer or "alpha" version
134numbers.
cb5772bb 135
692a467c 136=head1 PARSING AND COMPARING VERSIONS
cb5772bb 137
692a467c 138If you need to compare version numbers, but can't be sure whether they are
6369c739 139expressed as numbers, strings, v-strings or version objects, then you should
692a467c 140use version.pm to parse them all into objects for comparison.
cb5772bb 141
692a467c 142=head2 How to C<parse()> a version
cb5772bb 143
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144The C<parse()> method takes in anything that might be a version and returns
145a corresponding version object, doing any necessary conversion along the way.
cb5772bb 146
692a467c 147=over 2
cb5772bb 148
692a467c 149=item *
cb5772bb 150
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151Dotted-decimal: bare v-strings (v1.2.3) and strings with more than one
152decimal point and a leading 'v' ("v1.2.3"); NOTE you can technically use a
153v-string or strings with a leading-v and only one decimal point (v1.2 or
154"v1.2"), but you will confuse both yourself and others.
cb5772bb 155
692a467c 156=item *
cb5772bb 157
692a467c 158Decimal: regular decimal numbers (literal or in a string)
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159
160=back
161
692a467c 162Some examples:
cb5772bb 163
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164 $variable version->parse($variable)
165 --------- -------------------------
166 1.23 v1.230.0
167 "1.23" v1.230.0
168 v1.23 v1.23.0
169 "v1.23" v1.23.0
170 "1.2.3" v1.2.3
171 "v1.2.3" v1.2.3
cb5772bb 172
6369c739 173See L<version::Internals> for more on version number conversion.
cb5772bb 174
42bd538f 175=head2 How to check for a legal version string
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176
177If you do not want to actually create a full blown version object, but
178would still like to verify that a given string meets the criteria to
42bd538f 179be parsed as a version, there are two helper functions that can be
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180employed directly:
181
42bd538f 182=over 4
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183
184=item C<is_lax()>
185
6369c739 186The lax criteria corresponds to what is currently allowed by the
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187version parser. All of the following formats are acceptable
188for dotted-decimal formats strings:
61a0cb1c 189
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190 v1.2
191 1.2345.6
192 v1.23_4
193 1.2345
194 1.2345_01
61a0cb1c 195
42bd538f 196=item C<is_strict()>
61a0cb1c 197
8c72d156 198If you want to limit yourself to a much more narrow definition of what
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199a version string constitutes, C<is_strict()> is limited to version
200strings like the following list:
61a0cb1c 201
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202 v1.234.5
203 2.3456
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204
205=back
206
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207See L<version::Internals> for details of the regular expressions
208that define the legal version string forms, as well as how to use
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209those regular expressions in your own code if C<is_lax()> and
210C<is_strict()> are not sufficient for your needs.
61a0cb1c 211
692a467c 212=head2 How to compare version objects
cb5772bb 213
a8fb8d79 214Version objects overload the C<cmp> and C<< <=> >> operators. Perl
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215automatically generates all of the other comparison operators based on those
216two so all the normal logical comparisons will work.
cb5772bb 217
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218 if ( version->parse($v1) == version->parse($v2) ) {
219 # do stuff
220 }
219bf418 221
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222If a version object is compared against a non-version object, the non-object
223term will be converted to a version object using C<parse()>. This may give
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224surprising results:
225
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226 $v1 = version->parse("v0.95.0");
227 $bool = $v1 < 0.96; # FALSE since 0.96 is v0.960.0
219bf418 228
692a467c 229Always comparing to a version object will help avoid surprises:
cb5772bb 230
692a467c 231 $bool = $v1 < version->parse("v0.96.0"); # TRUE
cb5772bb 232
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233Note that "alpha" version objects (where the version string contains
234a trailing underscore segment) compare as less than the equivalent
235version without an underscore:
cb5772bb 236
6369c739 237 $bool = version->parse("1.23_45") < version->parse("1.2345"); # TRUE
cb5772bb 238
6369c739 239See L<version::Internals> for more details on "alpha" versions.
cb5772bb 240
692a467c 241=head1 OBJECT METHODS
cb5772bb 242
692a467c 243=head2 is_alpha()
cb5772bb 244
692a467c 245True if and only if the version object was created with a underscore, e.g.
cb5772bb 246
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247 version->parse('1.002_03')->is_alpha; # TRUE
248 version->declare('1.2.3_4')->is_alpha; # TRUE
cb5772bb 249
692a467c 250=head2 is_qv()
cb5772bb 251
692a467c 252True only if the version object is a dotted-decimal version, e.g.
cb5772bb 253
555bd962 254 version->parse('v1.2.0')->is_qv; # TRUE
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255 version->declare('v1.2')->is_qv; # TRUE
256 qv('1.2')->is_qv; # TRUE
257 version->parse('1.2')->is_qv; # FALSE
cb5772bb 258
692a467c 259=head2 normal()
cb5772bb 260
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261Returns a string with a standard 'normalized' dotted-decimal form with a
262leading-v and at least 3 components.
cb5772bb 263
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264 version->declare('v1.2')->normal; # v1.2.0
265 version->parse('1.2')->normal; # v1.200.0
8cb289bd 266
692a467c 267=head2 numify()
8cb289bd 268
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269Returns a value representing the object in a pure decimal form without
270trailing zeroes.
cb5772bb 271
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272 version->declare('v1.2')->numify; # 1.002
273 version->parse('1.2')->numify; # 1.2
cb5772bb 274
692a467c 275=head2 stringify()
cb5772bb 276
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277Returns a string that is as close to the original representation as possible.
278If the original representation was a numeric literal, it will be returned the
279way perl would normally represent it in a string. This method is used whenever
280a version object is interpolated into a string.
cb5772bb 281
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282 version->declare('v1.2')->stringify; # v1.2
283 version->parse('1.200')->stringify; # 1.200
284 version->parse(1.02_30)->stringify; # 1.023
cb5772bb 285
692a467c 286=head1 EXPORTED FUNCTIONS
cb5772bb 287
692a467c 288=head2 qv()
cb5772bb 289
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290This function is no longer recommended for use, but is maintained for
291compatibility with existing code. If you do not want to have it exported
292to your namespace, use this form:
cb5772bb 293
692a467c 294 use version 0.77 ();
cb5772bb 295
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296=head2 is_lax()
297
298(Not exported by default)
299
300This function takes a scalar argument and returns a boolean value indicating
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301whether the argument meets the "lax" rules for a version number. Leading and
302trailing spaces are not allowed.
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303
304=head2 is_strict()
305
306(Not exported by default)
307
308This function takes a scalar argument and returns a boolean value indicating
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309whether the argument meets the "strict" rules for a version number. Leading
310and trailing spaces are not allowed.
a525e6d7 311
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312=head1 AUTHOR
313
314John Peacock E<lt>jpeacock@cpan.orgE<gt>
315
316=head1 SEE ALSO
317
6369c739 318L<version::Internals>.
692a467c 319
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320L<perl>.
321
322=cut