# Declaring an old-style decimal $VERSION (use quotes!)
+ our $VERSION = "1.0203"; # recommended
use version 0.77; our $VERSION = version->parse("1.0203"); # formal
use version 0.77; our $VERSION = version->parse("1.02_03"); # alpha
=item Decimal Versions
The classic floating-point number $VERSION. The advantage to this style is
-that you don't need to do anything special, just type a number (without
-quotes) into your source file.
+that you don't need to do anything special, just type a number into your
+source file. Quoting is recommended, as it ensures that trailing zeroes
+("1.50") are preserved in any warnings or other output.
=item Dotted Decimal Versions
=back
-See L<VERSION OBJECT DETAILS> for further information.
-
=head1 DECLARING VERSIONS
If you have a module that uses a decimal $VERSION (floating point), and you
do not intend to ever change that, this module is not for you. There is
nothing that version.pm gains you over a simple $VERSION assignment:
- our $VERSION = 1.02;
+ our $VERSION = "1.02";
Since Perl v5.10.0 includes the version.pm comparison logic anyways,
you don't need to do anything at all.
use C<parse()> instead of declare. See the L<PARSING AND COMPARING VERSIONS>
for details.
-See also L<VERSION OBJECT DETAILS> for more on version number conversion,
+See also L<version::Internals> for more on version number conversion,
quoting, calculated version numbers and declaring developer or "alpha" version
numbers.
=head1 PARSING AND COMPARING VERSIONS
If you need to compare version numbers, but can't be sure whether they are
-expressed as numbers, strings, v-strings or version objects, then you can
+expressed as numbers, strings, v-strings or version objects, then you should
use version.pm to parse them all into objects for comparison.
=head2 How to C<parse()> a version
"1.2.3" v1.2.3
"v1.2.3" v1.2.3
-See L<VERSION OBJECT DETAILS> for more on version number conversion.
+See L<version::Internals> for more on version number conversion.
=head2 How to check for a legal version string
=item C<is_lax()>
-The lax criteria corresponds to what is currently allowed by the
+The lax criteria corresponds to what is currently allowed by the
version parser. All of the following formats are acceptable
for dotted-decimal formats strings:
See L<version::Internals> for details of the regular expressions
that define the legal version string forms, as well as how to use
-those regular expressions in your own code.
+those regular expressions in your own code if C<is_lax()> and
+C<is_strict()> are not sufficient for your needs.
=head2 How to compare version objects
$bool = $v1 < version->parse("v0.96.0"); # TRUE
-=head1 VERSION OBJECT DETAILS
-
-=head2 Equivalence between Decimal and Dotted-Decimal Versions
-
-When Perl 5.6.0 was released, the decision was made to provide a
-transformation between the old-style decimal versions and new-style
-dotted-decimal versions:
-
- 5.6.0 == 5.006000
- 5.005_04 == 5.5.40
-
-The floating point number is taken and split first on the single decimal
-place, then each group of three digits to the right of the decimal makes up
-the next digit, and so on until the number of significant digits is exhausted,
-B<plus> enough trailing zeros to reach the next multiple of three.
-
-This was the method that version.pm adopted as well. Some examples may be
-helpful:
-
- equivalent
- decimal zero-padded dotted-decimal
- ------- ----------- --------------
- 1.2 1.200 v1.200.0
- 1.02 1.020 v1.20.0
- 1.002 1.002 v1.2.0
- 1.0023 1.002300 v1.2.300
- 1.00203 1.002030 v1.2.30
- 1.002003 1.002003 v1.2.3
-
-=head2 Quoting rules
-
-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, especially when using the L<declare> or
-L<qv> methods. While you do not have to quote decimal numbers when
-creating version objects, it is always safe to quote B<all> initial values
-when using version.pm methods, as this will ensure that what you type is
-what is used.
-
-Additionally, if you quote your initializer, then the quoted value that goes
-B<in> will be be exactly what comes B<out> when your $VERSION is printed
-(stringified). If you do not quote your value, Perl's normal numeric handling
-comes into play and you may not get back what you were expecting.
-
-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
-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:
-
- $VERSION = version->new((qw$Revision: 1.4)[1]/10);
- print $VERSION; # yields 0.14
- $V2 = version->new(100/9); # Integer overflow in decimal number
- print $V2; # yields something like 11.111.111.100
-
-Perl 5.8.1 and beyond are able to automatically quote v-strings but
-that is not possible in earlier versions of Perl. In other words:
-
- $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 What about v-strings?
-
-There are two ways to enter v-strings: a bare number with two or more
-decimal points, or a bare number with one or more decimal points 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
-
-However, the use of bare v-strings to initialize version objects is
-B<strongly> discouraged in all circumstances. Also, bare
-v-strings are not completely supported in any version of Perl prior to
-5.8.1.
-
-If you insist on using bare v-strings with Perl > 5.6.0, be aware of the
-following limitations:
-
-1) For Perl releases 5.6.0 through 5.8.0, the v-string code merely guesses,
-based on some characteristics of v-strings. You B<must> use a three part
-version, e.g. 1.2.3 or v1.2.3 in order for this heuristic to be successful.
-
-2) For Perl releases 5.8.1 and later, v-strings have changed in the Perl
-core to be magical, which means that the version.pm code can automatically
-determine whether the v-string encoding was used.
-
-3) In all cases, a version created using v-strings will have a stringified
-form that has a leading 'v' character, for the simple reason that sometimes
-it is impossible to tell whether one was present initially.
-
-=head2 Alpha versions
-
-For module authors using CPAN, the convention has been to note unstable
-releases with an underscore in the version string. (See L<CPAN>.) version.pm
-follows this convention and alpha releases will test as being newer than the
-more recent stable release, and less than the next stable release. For
-dotted-decimal versions, only the last element may be separated by an
-underscore:
+Note that "alpha" version objects (where the version string contains
+a trailing underscore segment) compare as less than the equivalent
+version without an underscore:
- # Declaring
- use version 0.77; our $VERSION = version->declare("v1.2_3");
+ $bool = version->parse("1.23_45") < version->parse("1.2345"); # TRUE
- # Parsing
- $v1 = version->parse("v1.2_3");
- $v1 = version->parse("1.002_003");
+See L<version::Internals> for more details on "alpha" versions.
=head1 OBJECT METHODS
(Not exported by default)
This function takes a scalar argument and returns a boolean value indicating
-whether the argument meets the "lax" rules for a version number.
+whether the argument meets the "lax" rules for a version number. Leading and
+trailing spaces are not allowed.
=head2 is_strict()
(Not exported by default)
This function takes a scalar argument and returns a boolean value indicating
-whether the argument meets the "strict" rules for a version number.
+whether the argument meets the "strict" rules for a version number. Leading
+and trailing spaces are not allowed.
=head1 AUTHOR
=head1 SEE ALSO
-L<version::Internal>.
+L<version::Internals>.
L<perl>.
=head1 NAME
-version::Internal - Perl extension for Version Objects
+version::Internals - Perl extension for Version Objects
=head1 DESCRIPTION
Overloaded version objects for all modern versions of Perl. This documents
the internal data representation and underlying code for version.pm. See
L<version.pod> for daily usage. This document is only useful for users
-writing a subclass of version.pm or interested in the gory details.
+interested in the gory details.
-=head1 What IS a version
+=head1 WHAT IS A VERSION?
For the purposes of this module, a version "number" is a sequence of
-positive integer values separated by one or more decimal points and
-optionally a single underscore. This corresponds to what Perl itself
-uses for a version, as well as extending the "version as number" that
+positive integer values separated by one or more decimal points and
+optionally a single underscore. This corresponds to what Perl itself
+uses for a version, as well as extending the "version as number" that
is discussed in the various editions of the Camel book.
There are actually two distinct kinds of version objects:
Any version which "looks like a number", see L<Decimal Versions>. This
also includes versions with a single decimal point and a single embedded
-underscore, see L<Decimal Alpha Versions>, even though these must be quoted
+underscore, see L<Alpha Versions>, even though these must be quoted
to preserve the underscore formatting.
=item Dotted-Decimal Versions
=back
Both of these methods will produce similar version objects, in that
-the default stringification will yield the version L<Normal Form> only
+the default stringification will yield the version L<Normal Form> only
if required:
$v = version->new(1.002); # 1.002, but compares like 1.2.0
will have trailing zeros added to make up the difference, but only for
purposes of comparison with other version objects. For example:
- # Prints Equivalent to
+ # Prints Equivalent to
$v = version->new( 1.2); # 1.2 v1.200.0
$v = version->new( 1.02); # 1.02 v1.20.0
$v = version->new( 1.002); # 1.002 v1.2.0
$v = version->new( 1.00203); # 1.00203 v1.2.30
$v = version->new( 1.002003); # 1.002003 v1.2.3
-All of the preceding examples are true whether or not the input value is
-quoted. The important feature is that the input value contains only a
-single decimal. See also L<version/Alpha Versions> for how to handle
+All of the preceding examples are true whether or not the input value is
+quoted. The important feature is that the input value contains only a
+single decimal. See also L<Alpha Versions>.
-IMPORTANT NOTE: As shown above, if your Decimal version contains more
-than 3 significant digits after the decimal place, it will be split on
-each multiple of 3, so 1.0003 is equivalent to v1.0.300, due to the need
-to remain compatible with Perl's own 5.005_03 == 5.5.30 interpretation.
+IMPORTANT NOTE: As shown above, if your Decimal version contains more
+than 3 significant digits after the decimal place, it will be split on
+each multiple of 3, so 1.0003 is equivalent to v1.0.300, due to the need
+to remain compatible with Perl's own 5.005_03 == 5.5.30 interpretation.
Any trailing zeros are ignored for mathematical comparison purposes.
=head2 Dotted-Decimal Versions
These are the newest form of versions, and correspond to Perl's own
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 normally requires that the input parameter be quoted, although
+method normally requires that the input parameter be quoted, although
Perl's after 5.8.1 can use v-strings as a special form of quoting, but
this is highly discouraged.
uniformity. See also L<New Operator> for an additional method of
initializing version objects.
-Just like L<Decimal Versions>, Dotted-Decimal Versions can be used as
-L<version/Alpha Versions>.
+Just like L<Decimal Versions>, Dotted-Decimal Versions can be used as
+L<Alpha Versions>.
-=head2 Decimal Alpha Versions
+=head2 Alpha Versions
-The one time that a Decimal version must be quoted is when a alpha form is
-used with an otherwise Decimal version (i.e. a single decimal point). This
-is commonly used for CPAN releases, where CPAN or CPANPLUS will ignore alpha
-versions for automatic updating purposes. Since some developers have used
-only two significant decimal places for their non-alpha releases, the
-version object will automatically take that into account if the initializer
-is quoted. For example Module::Example was released to CPAN with the
-following sequence of $VERSION's:
+For module authors using CPAN, the convention has been to note unstable
+releases with an underscore in the version string. (See L<CPAN>.) version.pm
+follows this convention and alpha releases will test as being newer than the
+more recent stable release, and less than the next stable release. Only the
+last element may be separated by an underscore:
- # $VERSION Stringified
- 0.01 0.01
- 0.02 0.02
- 0.02_01 0.02_01
- 0.02_02 0.02_02
- 0.03 0.03
- etc.
+ # Declaring
+ use version 0.77; our $VERSION = version->declare("v1.2_3");
-The stringified form of Decimal versions will always be the same string
-that was used to initialize the version object.
+ # Parsing
+ $v1 = version->parse("v1.2_3");
+ $v1 = version->parse("1.002_003");
+
+Note that you B<must> quote the version when writing an alpha Decimal version.
+The stringified form of Decimal versions will always be the same string that
+was used to initialize the version object.
=head2 Regular Expressions for Version Parsing
where C<$PKGNAME> is another regular expression that defines the legal
forms for package names.
-=head1 High level design
+=head1 IMPLEMENTATION DETAILS
+
+=head2 Equivalence between Decimal and Dotted-Decimal Versions
+
+When Perl 5.6.0 was released, the decision was made to provide a
+transformation between the old-style decimal versions and new-style
+dotted-decimal versions:
+
+ 5.6.0 == 5.006000
+ 5.005_04 == 5.5.40
+
+The floating point number is taken and split first on the single decimal
+place, then each group of three digits to the right of the decimal makes up
+the next digit, and so on until the number of significant digits is exhausted,
+B<plus> enough trailing zeros to reach the next multiple of three.
+
+This was the method that version.pm adopted as well. Some examples may be
+helpful:
+
+ equivalent
+ decimal zero-padded dotted-decimal
+ ------- ----------- --------------
+ 1.2 1.200 v1.200.0
+ 1.02 1.020 v1.20.0
+ 1.002 1.002 v1.2.0
+ 1.0023 1.002300 v1.2.300
+ 1.00203 1.002030 v1.2.30
+ 1.002003 1.002003 v1.2.3
+
+=head2 Quoting Rules
+
+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, especially when using the L<declare> or
+L<qv> methods. While you do not have to quote decimal numbers when
+creating version objects, it is always safe to quote B<all> initial values
+when using version.pm methods, as this will ensure that what you type is
+what is used.
+
+Additionally, if you quote your initializer, then the quoted value that goes
+B<in> will be be exactly what comes B<out> when your $VERSION is printed
+(stringified). If you do not quote your value, Perl's normal numeric handling
+comes into play and you may not get back what you were expecting.
+
+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
+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:
+
+ $VERSION = version->new((qw$Revision: 1.4)[1]/10);
+ print $VERSION; # yields 0.14
+ $V2 = version->new(100/9); # Integer overflow in decimal number
+ print $V2; # yields something like 11.111.111.100
+
+Perl 5.8.1 and beyond are able to automatically quote v-strings but
+that is not possible in earlier versions of Perl. In other words:
+
+ $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 What about v-strings?
+
+There are two ways to enter v-strings: a bare number with two or more
+decimal points, or a bare number with one or more decimal points 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
+
+However, the use of bare v-strings to initialize version objects is
+B<strongly> discouraged in all circumstances. Also, bare
+v-strings are not completely supported in any version of Perl prior to
+5.8.1.
-=head2 version objects
+If you insist on using bare v-strings with Perl > 5.6.0, be aware of the
+following limitations:
-version.pm provides an overloaded version object that is designed to both
+1) For Perl releases 5.6.0 through 5.8.0, the v-string code merely guesses,
+based on some characteristics of v-strings. You B<must> use a three part
+version, e.g. 1.2.3 or v1.2.3 in order for this heuristic to be successful.
+
+2) For Perl releases 5.8.1 and later, v-strings have changed in the Perl
+core to be magical, which means that the version.pm code can automatically
+determine whether the v-string encoding was used.
+
+3) In all cases, a version created using v-strings will have a stringified
+form that has a leading 'v' character, for the simple reason that sometimes
+it is impossible to tell whether one was present initially.
+
+=head2 Version Object Internals
+
+version.pm provides an overloaded version object that is designed to both
encapsulate the author's intended $VERSION assignment as well as make it
completely natural to use those objects as if they were numbers (e.g. for
-comparisons). To do this, a version object contains both the original
+comparisons). To do this, a version object contains both the original
representation as typed by the author, as well as a parsed representation
to ease comparisons. Version objects employ L<overload> methods to
simplify code that needs to compare, print, etc the objects.
will also exclusively return the stringified form. See L<Stringification>
for more details.
-=head1 Usage question
+=head1 USAGE DETAILS
=head2 Using modules that use version.pm
=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 base version objects. Consequently,
-there is no overloaded numification available. If you want to use a
-version object in a Decimal context for some reason, see the L<numify>
-object method.
-
=over 4
-=item New Operator
+=item new()
-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.
+Like many OO interfaces, the new() method is used to initialize version
+objects. If two arguments are passed to C<new()>, the B<second> one will be
+used as if it were prefixed with "v". This is to support historical use of the
+C<qw> operator with 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:
$v1 = qv(1.2); # v1.2.0
$v2 = qv("1.2"); # also v1.2.0
-As you can see, either a bare number or a quoted string can usually
+As you can see, either a bare number or a quoted string can usually
be used interchangably, except in the case of a trailing zero, which
must be quoted to be converted properly. For this reason, it is strongly
recommended that all initializers to qv() be quoted strings instead of
require version;
Both methods will prevent the import() method from firing and exporting the
-C<qv()> sub. This is true of subclasses of version as well, see
-L<SUBCLASSING> for details.
+C<qv()> sub.
=back
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 "<version/Alpha versions" below
- $nver = version->new(1.002); # see "Decimal Versions" above
+ $ver = version->new("1.2.3.4"); # see "Quoting Rules"
+ $alpha = version->new("1.2.3_4"); # see "Alpha Versions"
+ $nver = version->new(1.002); # see "Decimal Versions"
=over 4
print $ver->stringify; # ditto
print $ver; # ditto
print $nver->normal; # prints as v1.2.0
- print $nver->stringify; # prints as 1.002, see "Stringification"
+ print $nver->stringify; # prints as 1.002, see "Stringification"
-In order to preserve the meaning of the processed version, the
+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:
=item Numification
Although all mathematical operations on version objects are forbidden
-by default, it is possible to retrieve a number which corresponds
+by default, it is possible to retrieve a number which 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
version->new("v1.2") v1.2
qv("1.2.3") 1.2.3
qv("v1.3.5") v1.3.5
- qv("1.2") v1.2 ### exceptional case
+ qv("1.2") v1.2 ### exceptional case
See also L<UNIVERSAL::VERSION>, as this also returns the stringified form
when used as a class method.
It is probably best to chose either the Decimal notation or the string
notation and stick with it, to reduce confusion. Perl6 version objects
-B<may> only support Decimal comparisons. See also L<Quoting>.
+B<may> only support Decimal comparisons. See also L<Quoting Rules>.
WARNING: Comparing version with unequal numbers of decimal points (whether
explicitly or implicitly initialized), may yield unexpected results at
$vobj = version->new($something);
if ( $vobj ) # true only if $something was non-blank
-You can also test whether a version object is an L<version/Alpha version>, for
+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:
=back
-=head2 Quoting
-
-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, especially when using the L<qv>() operator.
-In all cases, a floating point number passed to version->new() will be
-identically converted whether or not the value itself is quoted. This is
-not true for L<qv>(), however, when trailing zeros would be stripped on
-an unquoted input, which would result in a very different version object.
-
-In addition, in order to be compatible with earlier Perl version styles,
-any use of versions of the form 5.006001 will be translated as v5.6.1.
-In other words, a version with a single decimal point will be parsed as
-implicitly having three digits between subversions, but only for internal
-comparison purposes.
-
-The complicating factor is that in bare numbers (i.e. unquoted), the
-underscore is a legal Decimal character and is automatically stripped
-by the Perl tokenizer before the version code is called. However, if
-a number containing one or more decimals and an underscore is quoted, i.e.
-not bare, that is considered an L<version/Alpha 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
-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:
-
- $VERSION = version->new((qw$Revision: 1.4)[1]/10);
- print $VERSION; # yields 0.14
- $V2 = version->new(100/9); # Integer overflow in decimal number
- print $V2; # yields something like 11.111.111.100
-
-Perl 5.8.1 and beyond will be able to automatically quote v-strings but
-that is not possible in earlier versions of Perl. In other words:
-
- $version = version->new("v2.5.4"); # legal in all versions of Perl
- $newvers = version->new(v2.5.4); # legal only in Perl >= 5.8.1
-
-=head1 SUBCLASSING
-
-This module is specifically designed and tested to be easily subclassed.
-In practice, you only need to override the methods you want to change, but
-you have to take some care when overriding new() (since that is where all
-of the parsing takes place). For example, this is a perfect acceptable
-derived class:
-
- package myversion;
- use base version;
- sub new {
- my($self,$n)=@_;
- my $obj;
- # perform any special input handling here
- $obj = $self->SUPER::new($n);
- # and/or add additional hash elements here
- return $obj;
- }
-
-See also L<version::AlphaBeta> on CPAN for an alternate representation of
-version strings.
-
-B<NOTE:> Although the L<qv> operator is not a true class method, but rather a
-function exported into the caller's namespace, a subclass of version will
-inherit an import() function which will perform the correct magic on behalf
-of the subclass.
-
-=head1 EXPORT
-
-qv - Dotted-Decimal Version initialization operator
-
=head1 AUTHOR
John Peacock E<lt>jpeacock@cpan.orgE<gt>
projects / p5sagit/p5-mst-13.2.git / commitdiff