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diff --git a/Master/tlpkg/tlperl0/lib/version.pod b/Master/tlpkg/tlperl0/lib/version.pod new file mode 100755 index 00000000000..090b5969ee1 --- /dev/null +++ b/Master/tlpkg/tlperl0/lib/version.pod @@ -0,0 +1,365 @@ +=head1 NAME + +version - Perl extension for Version Objects + +=head1 SYNOPSIS + + # Parsing version strings (decimal or dotted-decimal) + + use version 0.77; # get latest bug-fixes and API + $ver = version->parse($string) + + # Declaring a dotted-decimal $VERSION (keep on one line!) + + use version 0.77; our $VERSION = version->declare("v1.2.3"); # formal + use version 0.77; our $VERSION = qv("v1.2.3"); # shorthand + use version 0.77; our $VERSION = qv("v1.2_3"); # alpha + + # Declaring an old-style decimal $VERSION (use quotes!) + + use version 0.77; our $VERSION = version->parse("1.0203"); # formal + use version 0.77; our $VERSION = version->parse("1.02_03"); # alpha + + # Comparing mixed version styles (decimals, dotted-decimals, objects) + + if ( version->parse($v1) == version->parse($v2) ) { + # do stuff + } + + # Sorting mixed version styles + + @ordered = sort { version->parse($a) <=> version->parse($b) } @list; + +=head1 DESCRIPTION + +Version objects were added to Perl in 5.10. This module implements version +objects for older version of Perl and provides the version object API for all +versions of Perl. All previous releases before 0.74 are deprecated and should +not be used due to incompatible API changes. Version 0.77 introduces the new +'parse' and 'declare' methods to standardize usage. You are strongly urged to +set 0.77 as a minimum in your code, e.g. + + use version 0.77; # even for Perl v.5.10.0 + +=head1 TYPES OF VERSION OBJECTS + +There are two different types of version objects, corresponding to the two +different styles of versions in use: + +=over 2 + +=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. + +=item Dotted Decimal Versions + +The more modern form of version assignment, with 3 (or potentially more) +integers seperated by decimal points (e.g. v1.2.3). This is the form that +Perl itself has used since 5.6.0 was released. The leading "v" is now +strongly recommended for clarity, and will throw a warning in a future +release if omitted. + +=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; + +Since Perl v5.10.0 includes the version.pm comparison logic anyways, +you don't need to do anything at all. + +=head2 How to convert a module from decimal to dotted-decimal + +If you have used a decimal $VERSION in the past and wish to switch to a +dotted-decimal $VERSION, then you need to make a one-time conversion to +the new format. + +B<Important Note>: you must ensure that your new $VERSION is numerically +greater than your current decimal $VERSION; this is not always obvious. First, +convert your old decimal version (e.g. 1.02) to a normalized dotted-decimal +form: + + $ perl -Mversion -e 'print version->parse("1.02")->normal' + v1.20.0 + +Then increment any of the dotted-decimal components (v1.20.1 or v1.21.0). + +=head2 How to C<declare()> a dotted-decimal version + + use version 0.77; our $VERSION = version->declare("v1.2.3"); + +The C<declare()> method always creates dotted-decimal version objects. When +used in a module, you B<must> put it on the same line as "use version" to +ensure that $VERSION is read correctly by PAUSE and installer tools. You +should also add 'version' to the 'configure_requires' section of your +module metadata file. See instructions in L<ExtUtils::MakeMaker> or +L<Module::Build> for details. + +B<Important Note>: Even if you pass in what looks like a decimal number +("1.2"), a dotted-decimal will be created ("v1.200.0"). To avoid confusion +or unintentional errors on older Perls, follow these guidelines: + +=over 2 + +=item * + +Always use a dotted-decimal with (at least) three components + +=item * + +Always use a leading-v + +=item * + +Always quote the version + +=back + +If you really insist on using version.pm with an ordinary decimal version, +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, +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 +use version.pm to parse them all into objects for comparison. + +=head2 How to C<parse()> a version + +The C<parse()> method takes in anything that might be a version and returns +a corresponding version object, doing any necessary conversion along the way. + +=over 2 + +=item * + +Dotted-decimal: bare v-strings (v1.2.3) and strings with more than one +decimal point and a leading 'v' ("v1.2.3"); NOTE you can technically use a +v-string or strings with a leading-v and only one decimal point (v1.2 or +"v1.2"), but you will confuse both yourself and others. + +=item * + +Decimal: regular decimal numbers (literal or in a string) + +=back + +Some examples: + + $variable version->parse($variable) + --------- ------------------------- + 1.23 v1.230.0 + "1.23" v1.230.0 + v1.23 v1.23.0 + "v1.23" v1.23.0 + "1.2.3" v1.2.3 + "v1.2.3" v1.2.3 + +See L<VERSION OBJECT DETAILS> for more on version number conversion. + +=head2 How to compare version objects + +Version objects overload the C<cmp> and C<< E<lt>=E<gt> >> operators. Perl +automatically generates all of the other comparison operators based on those +two so all the normal logical comparisons will work. + + if ( version->parse($v1) == version->parse($v2) ) { + # do stuff + } + +If a version object is compared against a non-version object, the non-object +term will be converted to a version object using C<parse()>. This may give +surprising results: + + $v1 = version->parse("v0.95.0"); + $bool = $v1 < 0.96; # FALSE since 0.96 is v0.960.0 + +Always comparing to a version object will help avoid surprises: + + $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: + + # Declaring + use version 0.77; our $VERSION = version->declare("v1.2_3"); + + # Parsing + $v1 = version->parse("v1.2_3"); + $v1 = version->parse("1.002_003"); + +=head1 OBJECT METHODS + +=head2 is_alpha() + +True if and only if the version object was created with a underscore, e.g. + + version->parse('1.002_03')->is_alpha; # TRUE + version->declare('1.2.3_4')->is_alpha; # TRUE + +=head2 is_qv() + +True only if the version object is a dotted-decimal version, e.g. + + version->parse('v1.2.0')->is_qv; # TRUE + version->declare('v1.2')->is_qv; # TRUE + qv('1.2')->is_qv; # TRUE + version->parse('1.2')->is_qv; # FALSE + +=head2 normal() + +Returns a string with a standard 'normalized' dotted-decimal form with a +leading-v and at least 3 components. + + version->declare('v1.2')->normal; # v1.2.0 + version->parse('1.2')->normal; # v1.200.0 + +=head2 numify() + +Returns a value representing the object in a pure decimal form without +trailing zeroes. + + version->declare('v1.2')->numify; # 1.002 + version->parse('1.2')->numify; # 1.2 + +=head2 stringify() + +Returns a string that is as close to the original representation as possible. +If the original representation was a numeric literal, it will be returned the +way perl would normally represent it in a string. This method is used whenever +a version object is interpolated into a string. + + version->declare('v1.2')->stringify; # v1.2 + version->parse('1.200')->stringify; # 1.200 + version->parse(1.02_30)->stringify; # 1.023 + +=head1 EXPORTED FUNCTIONS + +=head2 qv() + +This function is no longer recommended for use, but is maintained for +compatibility with existing code. If you do not want to have it exported +to your namespace, use this form: + + use version 0.77 (); + +=head1 AUTHOR + +John Peacock E<lt>jpeacock@cpan.orgE<gt> + +=head1 SEE ALSO + +L<version::Internal>. + +L<perl>. + +=cut |