-#!/usr/local/bin/perl -w
+#!/usr/bin/perl -w
package version;
use 5.005_03;
@ISA = qw(DynaLoader);
-$VERSION = (qw$Revision: 2.3 $)[1]/10;
+$VERSION = (qw$Revision: 2.7 $)[1]/10;
$CLASS = 'version';
$version = new version "12.2.1"; # must be quoted!
print $version; # 12.2.1
print $version->numify; # 12.002001
- if ( $version > 12.2 ) # true
+ if ( $version gt "v12.2" ) # true
$vstring = new version qw(v1.2); # must be quoted!
print $vstring; # 1.2
$betaver = new version "1.2_3"; # must be quoted!
print $betaver; # 1.2_3
- $perlver = new version "5.005_03"; # must be quoted!
+ $perlver = new version 5.005_03; # must not be quoted!
print $perlver; # 5.5.30
=head1 DESCRIPTION
version, as well as extending the "version as number" that is discussed
in the various editions of the Camel book.
-However, in order to be compatible with earlier Perl version styles,
-any use of versions of the form 5.006001 will be translated as 5.6.1,
-In other words, a version with a single decimal place will be parsed
-as implicitly having three places between subversion.
+There are actually two distinct ways to initialize versions:
+
+=over 4
+
+=item * Numeric Versions - any initial parameter which "looks like
+a number", see L<Numeric Versions>.
+
+=item * V-String Versions - any initial parameter which contains more
+than one decimal point, contains an embedded underscore, or has a
+leading 'v' see L<V-String Versions>.
+
+=back
+
+Both of these methods will produce similar version objects, in that
+the default stringification will always be in a reduced form, i.e.:
+
+ $v = new version 1.002003; # 1.2.3
+ $v2 = new version "1.2.3"; # 1.2.3
+ $v3 = new version v1.2.3; # 1.2.3 for Perl > v5.8.0
+ $v4 = new version 1.2.3; # 1.2.3 for Perl > v5.8.0
+
+Please see L<Quoting> for more details on how Perl will parse various
+input values.
Any value passed to the new() operator will be parsed only so far as it
contains a numeric, decimal, or underscore character. So, for example:
$v1 = new version "99 and 94/100 percent pure"; # $v1 == 99.0
$v2 = new version "something"; # $v2 == "" and $v2->numify == 0
-NOTE: it is strongly recommended that version objects only be created
-with numeric values based on the different types of versions in this
-documentation, see L<"Types of Versions Objects">. That way, there is
-no confusion about what constitutes the version.
+However, see L<New Operator> for one case where non-numeric text is
+acceptable when initializing version objects.
+
+=head2 Numeric Versions
+
+These correspond to historical versions of Perl itself prior to v5.6.0,
+as well as all other modules which follow the Camel rules for the
+$VERSION scalar. A numeric version is initialized with what looks like
+a floating point number. Leading zeros B<are> significant and trailing
+zeros are implied so that a minimum of three places is maintained
+between subversions. What this means is that any subversion (digits
+to the right of the decimal place) that contains less than three digits
+will have trailing zeros added to make up the difference. For example:
+
+ $v = new version 1.2; # 1.200
+ $v = new version 1.02; # 1.20
+ $v = new version 1.002; # 1.2
+ $v = new version 1.0023; # 1.2.300
+ $v = new version 1.00203; # 1.2.30
+ $v = new version 1.002_03; # 1.2.30 See L<Quoting>
+ $v = new version 1.002003; # 1.2.3
+
+All of the preceeding examples except the second to last are true
+whether or not the input value is quoted. The important feature is that
+the input value contains only a single decimal.
+
+=head2 V-String Versions
+
+These are the newest form of versions, and correspond to Perl's own
+version style beginning with v5.6.0. Starting with Perl v5.10.0,
+this is likely to be the preferred form. This method requires that
+the input parameter be quoted, although Perl > v5.9.0 can use bare
+v-strings as a special form of quoting.
+
+Unlike L<Numeric Versions>, V-String Versions must either have more than
+a single decimal point, e.g. "5.6.1" B<or> must be prefaced by a "v"
+like this "v5.6" (much like v-string notation). In fact, with the
+newest Perl v-strings themselves can be used to initialize version
+objects. Also unlike L<Numeric Versions>, leading zeros are B<not>
+significant, and trailing zeros must be explicitely specified (i.e.
+will not be automatically added). In addition, the subversions are
+not enforced to be three decimal places.
+
+So, for example:
+
+ $v = new version "v1.2"; # 1.2
+ $v = new version "v1.002"; # 1.2
+ $v = new version "1.2.3"; # 1.2.3
+ $v = new version "v1.2.3"; # 1.2.3
+ $v = new version "v1.0003"; # 1.3
+
+In additional to conventional versions, V-String Versions can be
+used to create L<Beta Versions>.
+
+In general, V-String Versions permit the greatest amount of freedom
+to specify a version, whereas Numeric Versions enforce a certain
+uniformity. See also L<New Operator> for an additional method of
+initializing version objects.
=head2 Object Methods
Overloading has been used with version objects to provide a natural
interface for their use. All mathematical operations are forbidden,
-since they don't make any sense for versions. For the subsequent
-examples, the following two objects will be used:
+since they don't make any sense for versions.
+
+=over 4
+
+=item * New Operator - Like all OO interfaces, the new() operator is
+used to initialize version objects. One way to increment versions
+when programming is to use the CVS variable $Revision, which is
+automatically incremented by CVS every time the file is committed to
+the repository.
+
+=back
+
+In order to facilitate this feature, the following
+code can be employed:
+
+ $VERSION = new version qw$Revision: 2.7 $;
+
+and the version object will be created as if the following code
+were used:
+
+ $VERSION = new version "v2.6";
+
+In other words, the version will be automatically parsed out of the
+string, and it will be quoted to preserve the meaning CVS normally
+carries for versions.
+
+For the subsequent examples, the following two objects will be used:
$ver = new version "1.2.3"; # see "Quoting" below
$beta = new version "1.2_3"; # see "Beta versions" below
+=over 4
+
=item * Stringification - Any time a version object is used as a string,
a stringified representation is returned in reduced form (no extraneous
zeros):
+=back
+
print $ver->stringify; # prints 1.2.3
print $ver; # same thing
+=over 4
+
=item * Numification - although all mathematical operations on version
objects are forbidden by default, it is possible to retrieve a number
which roughly corresponds to the version object through the use of the
which corresponds a version object, all sub versions are assumed to have
three decimal places. So for example:
+=back
+
print $ver->numify; # prints 1.002003
+=over 4
+
=item * Comparison operators - Both cmp and <=> operators perform the
same comparison between terms (upgrading to a version object
automatically). Perl automatically generates all of the other comparison
-operators based on those two. For example, the following relations hold:
+operators based on those two. In addition to the obvious equalities
+listed below, appending a single trailing 0 term does not change the
+value of a version for comparison purposes. In other words "v1.2" and
+"v1.2.0" are identical versions.
+
+=back
+
+For example, the following relations hold:
- As Number As String Truth Value
- --------- ------------ -----------
+ As Number As String Truth Value
+ --------- ------------ -----------
$ver > 1.0 $ver gt "1.0" true
$ver < 2.5 $ver lt true
$ver != 1.3 $ver ne "1.3" true
=head2 Quoting
Because of the nature of the Perl parsing and tokenizing routines,
-you should always quote the parameter to the new() operator/method. The
-exact notation is vitally important to correctly determine the version
-that is requested. You don't B<have> to quote the version parameter,
-but you should be aware of what Perl is likely to do in those cases.
+certain initialization values B<must> be quoted in order to correctly
+parse as the intended version, and additionally, some initial values
+B<must not> be quoted to obtain the intended version.
+
+Except for L<Beta versions>, any version initialized with something
+that looks like a number (a single decimal place) will be parsed in
+the same way whether or not the term is quoted. In order to be
+compatible with earlier Perl version styles, any use of versions of
+the form 5.006001 will be translated as 5.6.1. In other words, a
+version with a single decimal place will be parsed as implicitly
+having three places between subversions.
+
+The complicating factor is that in bare numbers (i.e. unquoted), the
+underscore is a legal numeric character and is automatically stripped
+by the Perl tokenizer before the version code is called. However, if
+a number containing a single decimal and an underscore is quoted, i.e.
+not bare, that is considered a L<Beta Version> and the underscore is
+significant.
If you use a mathematic formula that resolves to a floating point number,
you are dependent on Perl's conversion routines to yield the version you
$V2 = new version 100/9; # Integer overflow in decimal number
print $V2; # yields 11_1285418553
-You B<can> use a bare number, if you only have a major and minor version,
-since this should never in practice yield a floating point notation
-error. For example:
-
- $VERSION = new version 10.2; # almost certainly ok
- $VERSION = new version "10.2"; # guaranteed ok
-
Perl 5.9.0 and beyond will be able to automatically quote v-strings
(which may become the recommended notation), but that is not possible in
earlier versions of Perl. In other words:
=head2 Types of Versions Objects
-There are three basic types of Version Objects:
+There are two types of Version Objects:
+
+=over 4
=item * Ordinary versions - These are the versions that normal
modules will use. Can contain as many subversions as required.
In particular, those using RCS/CVS can use one of the following:
- $VERSION = new version (qw$Revision: 2.3 $)[1]; # all Perls
- $VERSION = new version qw$Revision: 2.3 $[1]; # Perl >= 5.6.0
+=back
+
+ $VERSION = new version qw$Revision: 2.7 $;
and the current RCS Revision for that file will be inserted
automatically. If the file has been moved to a branch, the
your module version by using the Revision number from the primary
file in a distribution, see L<ExtUtils::MakeMaker/"VERSION_FROM">.
+=over 4
+
=item * Beta versions - For module authors using CPAN, the
convention has been to note unstable releases with an underscore
in the version string, see L<CPAN>. Beta releases will test as being
newer than the more recent stable release, and less than the next
stable release. For example:
+=back
+
$betaver = new version "12.3_1"; # must quote
obeys the relationship
where the subversion is identical but the beta release is less than
the non-beta release.
-=item * Perl-style versions - an exceptional case is versions that
-were only used by Perl releases prior to 5.6.0. If a version
-string contains an underscore immediately followed by a zero followed
-by a non-zero number, the version is processed according to the rules
-described in L<perldelta/Improved Perl version numbering system>
-released with Perl 5.6.0. As an example:
-
- $perlver = new version "5.005_03";
-
-is interpreted, not as a beta release, but as the version 5.5.30, NOTE
-that the major and minor versions are unchanged but the subversion is
-multiplied by 10, since the above was implicitly read as 5.005.030.
-There are modules currently on CPAN which may fall under of this rule, so
-module authors are urged to pay close attention to what version they are
-specifying.
-
=head2 Replacement UNIVERSAL::VERSION
In addition to the version objects, this modules also replaces the core
UNIVERSAL::VERSION function with one that uses version objects for its
-comparisons. So, for example, with all existing versions of Perl,
-something like the following pseudocode would fail:
-
- package vertest;
- $VERSION = 0.45;
-
- package main;
- use vertest 0.5;
-
-even though those versions are meant to be read as 0.045 and 0.005
-respectively. The UNIVERSAL::VERSION replacement function included
-with this module changes that behavior so that it will B<not> fail.
+comparisons.
=head1 EXPORT
https://perl5.git.perl.org / perl5.git / blobdiff