-#!/usr/bin/perl -w
+#!perl -w
package version;
use 5.005_03;
use strict;
+require Exporter;
require DynaLoader;
-use vars qw(@ISA $VERSION $CLASS);
+use vars qw(@ISA $VERSION $CLASS @EXPORT);
-@ISA = qw(DynaLoader);
+@ISA = qw(Exporter DynaLoader);
-$VERSION = (qw$Revision: 2.7 $)[1]/10;
+@EXPORT = qw(qv);
+
+$VERSION = 0.39; # stop using CVS and switch to subversion
$CLASS = 'version';
=head1 SYNOPSIS
use version;
- $version = new version "12.2.1"; # must be quoted!
+ $version = version->new("12.2.1"); # must be quoted for Perl < 5.8.1
print $version; # 12.2.1
print $version->numify; # 12.002001
- if ( $version gt "v12.2" ) # true
-
- $vstring = new version qw(v1.2); # must be quoted!
- print $vstring; # 1.2
+ if ( $version gt "12.2" ) # true
- $betaver = new version "1.2_3"; # must be quoted!
- print $betaver; # 1.2_3
+ $alphaver = version->new("1.2_3"); # must be quoted!
+ print $alphaver; # 1.2_3
+ print $alphaver->is_alpha(); # true
+
+ $ver = qv(1.2); # 1.2.0
+ $ver = qv("1.2"); # 1.2.0
- $perlver = new version 5.005_03; # must not be quoted!
+ $perlver = version->new(5.005_03); # must not be quoted!
print $perlver; # 5.5.30
=head1 DESCRIPTION
Overloaded version objects for all versions of Perl. This module
implements all of the features of version objects which will be part
-of Perl 5.10.0 except automatic v-string handling. See L<"Quoting">.
+of Perl 5.10.0 except automatic version object creation.
=head2 What IS a version
=over 4
-=item * Numeric Versions - any initial parameter which "looks like
-a number", see L<Numeric Versions>.
+=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>.
+=item * Quoted Versions
+
+Any initial parameter which contains more than one decimal point
+or contains an embedded underscore, see L<Quoted Versions>. The
+most recent development version of Perl (5.9.x) and the next major
+release (5.10.0) will automatically create version objects for bare
+numbers containing more than one decimal point in the appropriate
+context.
=back
Both of these methods will produce similar version objects, in that
-the default stringification will always be in a reduced form, i.e.:
+the default stringification will yield the version L<Normal Form> only
+if required:
- $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
+ $v = version->new(1.002); # 1.002, but compares like 1.2.0
+ $v = version->new(1.002003); # 1.2.3
+ $v2 = version->new( "1.2.3"); # 1.2.3
+ $v3 = version->new( 1.2.3); # 1.2.3 for Perl >= 5.8.1
-Please see L<Quoting> for more details on how Perl will parse various
+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
+ $v1 = version->new("99 and 94/100 percent pure"); # $v1 == 99.0
+ $v2 = version->new("something"); # $v2 == "" and $v2->numify == 0
However, see L<New Operator> for one case where non-numeric text is
acceptable when initializing version objects.
+=head2 What about v-strings?
+
+Beginning with Perl 5.6.0, an alternate method to code arbitrary strings
+of bytes was introduced, called v-strings. They were intended to be an
+easy way to enter, for example, Unicode strings (which contain two bytes
+per character). Some programs have used them to encode printer control
+characters (e.g. CRLF). They were also intended to be used for $VERSION.
+Their use has been problematic from the start and they will be phased out
+beginning in Perl 5.10.0.
+
+There are two ways to enter v-strings: a bare number with two or more
+decimal places, or a bare number with one or more decimal places and a
+leading 'v' character (also bare). For example:
+
+ $vs1 = 1.2.3; # encoded as \1\2\3
+ $vs2 = v1.2; # encoded as \1\2
+
+The first of those two syntaxes is destined to be the default way to create
+a version object in 5.10.0, whereas the second will issue a mandatory
+deprecation warning beginning at the same time. In both cases, a v-string
+encoded version will always be stringified in the version L<Normal Form>.
+
+Consequently, the use of v-strings to initialize version objects with
+this module is only possible with Perl 5.8.1 or better (which contain special
+code to enable it). Their use is B<strongly> discouraged in all
+circumstances (especially the leading 'v' style), since the meaning will
+change depending on which Perl you are running. It is better to use
+L<"Quoted Versions"> to ensure the proper interpretation.
+
=head2 Numeric Versions
-These correspond to historical versions of Perl itself prior to v5.6.0,
+These correspond to historical versions of Perl itself prior to 5.6.0,
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
+will have trailing zeros added to make up the difference, but only for
+purposes of comparison with other version objects. For example:
+
+ $v = version->new( 1.2); # prints 1.2, compares as 1.200.0
+ $v = version->new( 1.02); # prints 1.02, compares as 1.20.0
+ $v = version->new( 1.002); # prints 1.002, compares as 1.2.0
+ $v = version->new( 1.0023); # 1.2.300
+ $v = version->new( 1.00203); # 1.2.30
+ $v = version->new( 1.002_03); # 1.2.30 See "Quoting"
+ $v = version->new( 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
+IMPORTANT NOTE: If your numeric version contains more than 3 significant
+digits after the decimal place, it will be split on each multiple of 3, so
+1.0003 becomes 1.0.300, due to the need to remain compatible with Perl's
+own 5.005_03 == 5.5.30 interpretation.
+
+=head2 Quoted 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.
+version style beginning with 5.6.0. Starting with Perl 5.10.0,
+and most likely Perl 6, this is likely to be the preferred form. This
+method requires that the input parameter be quoted, although Perl's after
+5.9.0 can use bare numbers with multiple decimal places as a special form
+of quoting.
+
+Unlike L<Numeric Versions>, Quoted Versions may have more than
+a single decimal point, e.g. "5.6.1" (for all versions of Perl). If a
+Quoted Version has only one decimal place (and no embedded underscore),
+it is interpreted exactly like a L<Numeric Version>.
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
+ $v = version->new( "1.002"); # 1.2
+ $v = version->new( "1.2.3"); # 1.2.3
+ $v = version->new("1.0003"); # 1.0.300
-In additional to conventional versions, V-String Versions can be
-used to create L<Beta Versions>.
+In addition to conventional versions, Quoted Versions can be
+used to create L<Alpha Versions>.
-In general, V-String Versions permit the greatest amount of freedom
-to specify a version, whereas Numeric Versions enforce a certain
+In general, Quoted 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.
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.
+since they don't make any sense for base version objects.
=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.
+=item * New Operator
-=back
+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.
In order to facilitate this feature, the following
code can be employed:
- $VERSION = new version qw$Revision: 2.7 $;
+ $VERSION = version->new(qw$Revision: 2.7 $);
and the version object will be created as if the following code
were used:
- $VERSION = new version "v2.6";
+ $VERSION = version->new("v2.7");
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.
+carries for versions. The CVS $Revision$ increments differently from
+numeric versions (i.e. 1.10 follows 1.9), so it must be handled as if
+it were a L<Quoted Version>.
+
+New in 0.38, a new version object can be created as a copy of an existing
+version object:
-For the subsequent examples, the following two objects will be used:
+ $v1 = version->new(12.3);
+ $v2 = version->new($v1);
- $ver = new version "1.2.3"; # see "Quoting" below
- $beta = new version "1.2_3"; # see "Beta versions" below
+and $v1 and $v2 will be identical.
+
+=back
=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):
+=item * qv()
+
+An alternate way to create a new version object is through the exported
+qv() sub. This is not strictly like other q? operators (like qq, qw),
+in that the only delimiters supported are parentheses (or spaces). It is
+the best way to initialize a short version without triggering the floating
+point interpretation. For example:
+
+ $v1 = qv(1.2); # 1.2.0
+ $v2 = qv("1.2"); # also 1.2.0
+
+As you can see, either a bare number or a quoted string can be used, and
+either will yield the same version number.
=back
- print $ver->stringify; # prints 1.2.3
- print $ver; # same thing
+For the subsequent examples, the following three objects will be used:
+
+ $ver = version->new("1.2.3.4"); # see "Quoting" below
+ $alpha = version->new("1.2.3_4"); # see "Alpha versions" below
+ $nver = version->new(1.2); # see "Numeric Versions" above
=over 4
-=item * Numification - although all mathematical operations on version
-objects are forbidden by default, it is possible to retrieve a number
-which roughly corresponds to the version object through the use of the
-$obj->numify method. For formatting purposes, when displaying a number
-which corresponds a version object, all sub versions are assumed to have
-three decimal places. So for example:
+=item * Normal Form
+
+For any version object which is initialized with multiple decimal
+places (either quoted or if possible v-string), or initialized using
+the L<qv()> operator, the stringified representation is returned in
+a normalized or reduced form (no extraneous zeros):
+
+ print $ver->normal; # prints as 1.2.3
+ print $ver->stringify; # ditto
+ print $ver; # ditto
+ print $nver->normal; # prints as 1.2.0
+ print $nver->stringify; # prints as 1.2, see "Stringification"
+
+In order to preserve the meaning of the processed version, the
+normalized representation will always contain at least three sub terms.
+In other words, the following is guaranteed to always be true:
+
+ my $newver = version->new($ver->stringify);
+ if ($newver eq $ver ) # always true
+ {...}
=back
+=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 $obj->numify
+method. For formatting purposes, when displaying a number which
+corresponds a version object, all sub versions are assumed to have
+three decimal places. So for example:
+
print $ver->numify; # prints 1.002003
+ print $nver->numify; # prints 1.2
+
+Unlike the stringification operator, there is never any need to append
+trailing zeros to preserve the correct version value.
+
+=back
=over 4
-=item * Comparison operators - Both cmp and <=> operators perform the
-same comparison between terms (upgrading to a version object
-automatically). Perl automatically generates all of the other comparison
-operators based on those two. In addition to the obvious equalities
-listed below, appending a single trailing 0 term does not change the
-value of a version for comparison purposes. In other words "v1.2" and
-"v1.2.0" are identical versions.
+=item * Stringification
+
+In order to mirror as much as possible the existing behavior of ordinary
+$VERSION scalars, the stringification operation will display differently,
+depending on whether the version was initialized as a L<Numeric Version>
+or L<Quoted Version>.
+
+What this means in practice is that if the normal CPAN and Camel rules are
+followed ($VERSION is a floating point number with no more than 3 decimal
+places), the stringified output will be exactly the same as the numified
+output. There will be no visible difference, although the internal
+representation will be different, and the L<Comparison operators> will
+function using the internal coding.
+
+If a version object is initialized using a L<Quoted Version> form, or if
+the number of significant decimal places exceed three, then the stringified
+form will be the L<Normal Form>. The $obj->normal operation can always be
+used to produce the L<Normal Form>, even if the version was originally a
+L<Numeric Version>.
+
+ print $ver->stringify; # prints 1.2.3
+ print $nver->stringify; # prints 1.2
=back
+=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.
+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 "1.2.0" will compare as identical.
+
For example, the following relations hold:
As Number As String Truth Value
$ver != 1.3 $ver ne "1.3" true
$ver == 1.2 $ver eq "1.2" false
$ver == 1.2.3 $ver eq "1.2.3" see discussion below
- $ver == v1.2.3 $ver eq "v1.2.3" ditto
-In versions of Perl prior to the 5.9.0 development releases, it is not
-permitted to use bare v-strings in either form, due to the nature of Perl's
-parsing operation. After that version (and in the stable 5.10.0 release),
-v-strings can be used with version objects without problem, see L<"Quoting">
-for more discussion of this topic. In the case of the last two lines of
-the table above, only the string comparison will be true; the numerical
-comparison will test false. However, you can do this:
+It is probably best to chose either the numeric notation or the string
+notation and stick with it, to reduce confusion. Perl6 version objects
+B<may> only support numeric comparisons. See also L<"Quoting">.
+
+WARNING: Comparing version with unequal numbers of decimal places (whether
+explicitely or implicitely initialized), may yield unexpected results at
+first glance. For example, the following inequalities hold:
- $ver == "1.2.3" or $ver == "v1.2.3" # both true
+ version->new(0.96) > version->new(0.95); # 0.960.0 > 0.950.0
+ version->new("0.96.1") < version->new(0.95); # 0.096.1 < 0.950.0
+
+For this reason, it is best to use either exclusively L<Numeric Versions> or
+L<Quoted Versions> with multiple decimal places.
+
+=back
+
+=over 4
-even though you are doing a "numeric" comparison with a "string" value.
-It is probably best to chose either the numeric notation or the string
-notation and stick with it, to reduce confusion. See also L<"Quoting">.
+=item * Logical Operators
+
+If you need to test whether a version object
+has been initialized, you can simply test it directly:
+
+ $vobj = version->new($something);
+ if ( $vobj ) # true only if $something was non-blank
+
+You can also test whether a version object is an L<Alpha version>, for
+example to prevent the use of some feature not present in the main
+release:
+
+ $vobj = version->new("1.2_3"); # MUST QUOTE
+ ...later...
+ if ( $vobj->is_alpha ) # True
+
+=back
=head2 Quoting
-Because of the nature of the Perl parsing and tokenizing routines,
+Because of the nature of the Perl parsing and tokenizing routines,
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
+Except for L<Alpha 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 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
+a number containing one or more decimals and an underscore is quoted, i.e.
+not bare, that is considered a L<Alpha Version> and the underscore is
significant.
If you use a mathematic formula that resolves to a floating point number,
expect. You are pretty safe by dividing by a power of 10, for example,
but other operations are not likely to be what you intend. For example:
- $VERSION = new version (qw$Revision: 1.4)[1]/10;
+ $VERSION = version->new((qw$Revision: 1.4)[1]/10);
print $VERSION; # yields 0.14
- $V2 = new version 100/9; # Integer overflow in decimal number
- print $V2; # yields 11_1285418553
+ $V2 = version->new(100/9); # Integer overflow in decimal number
+ print $V2; # yields something like 11.111.111.100
-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:
+Perl 5.8.1 and beyond will be able to automatically quote v-strings
+(although a warning may be issued under 5.9.x and 5.10.0), but that
+is not possible in earlier versions of Perl. In other words:
- $version = new version "v2.5.4"; # legal in all versions of Perl
- $newvers = new version v2.5.4; # legal only in Perl > 5.9.0
+ $version = version->new("v2.5.4"); # legal in all versions of Perl
+ $newvers = version->new(v2.5.4); # legal only in Perl >= 5.8.1
=head2 Types of Versions 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:
+=item * Ordinary versions
-=back
+These are the versions that normal modules will use. Can contain as
+many subversions as required. In particular, those using RCS/CVS can
+use the following:
- $VERSION = new version qw$Revision: 2.7 $;
+ $VERSION = version->new(qw$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
-Revision will have three or more elements; otherwise, it will
-have only two. This allows you to automatically increment
-your module version by using the Revision number from the primary
-file in a distribution, see L<ExtUtils::MakeMaker/"VERSION_FROM">.
+and the current RCS Revision for that file will be inserted
+automatically. If the file has been moved to a branch, the Revision
+will have three or more elements; otherwise, it will have only two.
+This allows you to automatically increment your module version by
+using the Revision number from the primary file in a distribution, see
+L<ExtUtils::MakeMaker/"VERSION_FROM">.
-=over 4
+=item * Alpha versions
-=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:
+For module authors using CPAN, the convention has been to note
+unstable releases with an underscore in the version string, see
+L<CPAN>. Alpha 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
+ $alphaver = version->new("12.3_1"); # must quote
obeys the relationship
- 12.3 < $betaver < 12.4
+ 12.3 < $alphaver < 12.4
As a matter of fact, if is also true that
- 12.3.0 < $betaver < 12.3.1
+ 12.3.0 < $alphaver < 12.3.1
+
+where the subversion is identical but the alpha release is less than
+the non-alpha release.
+
+Alpha versions with a single decimal place will be treated exactly as if
+they were L<Numeric Versions>, for parsing purposes. The stringification for
+alpha versions with a single decimal place may seem suprising, since any
+trailing zeros will visible. For example, the above $alphaver will print as
+
+ 12.300_100
+
+Alpha versions with more than a single decimal place will be treated
+exactly as if they were L<Quoted Versions>, and will display without any
+trailing (or leading) zeros, in the L<Version Normal> form. For example,
-where the subversion is identical but the beta release is less than
-the non-beta release.
+ $newver = version->new("12.3.1_1");
+ print $newver; # 12.3.1_1
=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.
+comparisons. The return from this operator is always the numified form,
+and the warning message generated includes both the numified and normal
+forms (for clarity).
+
+For example:
+
+ package Foo;
+ $VERSION = 1.2;
+
+ package Bar;
+ $VERSION = "1.3.5"; # works with all Perl's (since it is quoted)
+
+ package main;
+ use version;
+
+ print $Foo::VERSION; # prints 1.2
+
+ print $Bar::VERSION; # prints 1.003005
+
+ eval "use CGI 10"; # some far future release
+ print $@; # prints "CGI version 10 (10.0.0) required..."
+
+IMPORTANT NOTE: This may mean that code which searches for a specific
+string (to determine whether a given module is available) may need to be
+changed.
+
+The replacement UNIVERSAL::VERSION, when used as a function, like this:
+
+ print $module->VERSION;
+
+will follow the stringification rules; i.e. Numeric versions will be displayed
+with the numified format, and the rest will be displayed with the Normal
+format. Technically, the $module->VERSION function returns a string (PV) that
+can be converted to a number following the normal Perl rules, when used in a
+numeric context.
+
=head1 EXPORT
-None by default.
+qv - quoted version initialization operator
=head1 AUTHOR
https://perl5.git.perl.org / perl5.git / blobdiff