#!perl -w
package version;
-use 5.005_03;
+use 5.005_04;
use strict;
-require Exporter;
-use vars qw(@ISA $VERSION $CLASS @EXPORT);
+use vars qw(@ISA $VERSION $CLASS $STRICT $LAX *declare *qv);
-@ISA = qw(Exporter);
+$VERSION = 0.82;
-@EXPORT = qw(qv);
+$CLASS = 'version';
-$VERSION = 0.52;
+#--------------------------------------------------------------------------#
+# Version regexp components
+#--------------------------------------------------------------------------#
-$CLASS = 'version';
+# Fraction part of a decimal version number. This is a common part of
+# both strict and lax decimal versions
+
+my $FRACTION_PART = qr/\.[0-9]+/;
+
+# First part of either decimal or dotted-decimal strict version number.
+# Unsigned integer with no leading zeroes (except for zero itself) to
+# avoid confusion with octal.
+
+my $STRICT_INTEGER_PART = qr/0|[1-9][0-9]*/;
+
+# First part of either decimal or dotted-decimal lax version number.
+# Unsigned integer, but allowing leading zeros. Always interpreted
+# as decimal. However, some forms of the resulting syntax give odd
+# results if used as ordinary Perl expressions, due to how perl treats
+# octals. E.g.
+# version->new("010" ) == 10
+# version->new( 010 ) == 8
+# version->new( 010.2) == 82 # "8" . "2"
+
+my $LAX_INTEGER_PART = qr/[0-9]+/;
+
+# Second and subsequent part of a strict dotted-decimal version number.
+# Leading zeroes are permitted, and the number is always decimal.
+# Limited to three digits to avoid overflow when converting to decimal
+# form and also avoid problematic style with excessive leading zeroes.
+
+my $STRICT_DOTTED_DECIMAL_PART = qr/\.[0-9]{1,3}/;
+
+# Second and subsequent part of a lax dotted-decimal version number.
+# Leading zeroes are permitted, and the number is always decimal. No
+# limit on the numerical value or number of digits, so there is the
+# possibility of overflow when converting to decimal form.
+
+my $LAX_DOTTED_DECIMAL_PART = qr/\.[0-9]+/;
+
+# Alpha suffix part of lax version number syntax. Acts like a
+# dotted-decimal part.
+
+my $LAX_ALPHA_PART = qr/_[0-9]+/;
+
+#--------------------------------------------------------------------------#
+# Strict version regexp definitions
+#--------------------------------------------------------------------------#
+
+# Strict decimal version number.
+
+my $STRICT_DECIMAL_VERSION =
+ qr/ $STRICT_INTEGER_PART $FRACTION_PART? /x;
+
+# Strict dotted-decimal version number. Must have both leading "v" and
+# at least three parts, to avoid confusion with decimal syntax.
+
+my $STRICT_DOTTED_DECIMAL_VERSION =
+ qr/ v $STRICT_INTEGER_PART $STRICT_DOTTED_DECIMAL_PART{2,} /x;
+
+# Complete strict version number syntax -- should generally be used
+# anchored: qr/ \A $STRICT \z /x
+
+$STRICT =
+ qr/ $STRICT_DECIMAL_VERSION | $STRICT_DOTTED_DECIMAL_VERSION /x;
+
+#--------------------------------------------------------------------------#
+# Lax version regexp definitions
+#--------------------------------------------------------------------------#
+
+# Lax decimal version number. Just like the strict one except for
+# allowing an alpha suffix or allowing a leading or trailing
+# decimal-point
+
+my $LAX_DECIMAL_VERSION =
+ qr/ $LAX_INTEGER_PART (?: \. | $FRACTION_PART $LAX_ALPHA_PART? )?
+ |
+ $FRACTION_PART $LAX_ALPHA_PART?
+ /x;
+
+# Lax dotted-decimal version number. Distinguished by having either
+# leading "v" or at least three non-alpha parts. Alpha part is only
+# permitted if there are at least two non-alpha parts. Strangely
+# enough, without the leading "v", Perl takes .1.2 to mean v0.1.2,
+# so when there is no "v", the leading part is optional
+
+my $LAX_DOTTED_DECIMAL_VERSION =
+ qr/
+ v $LAX_INTEGER_PART (?: $LAX_DOTTED_DECIMAL_PART+ $LAX_ALPHA_PART? )?
+ |
+ $LAX_INTEGER_PART? $LAX_DOTTED_DECIMAL_PART{2,} $LAX_ALPHA_PART?
+ /x;
+
+# Complete lax version number syntax -- should generally be used
+# anchored: qr/ \A $LAX \z /x
+#
+# The string 'undef' is a special case to make for easier handling
+# of return values from ExtUtils::MM->parse_version
+
+$LAX =
+ qr/ undef | $LAX_DECIMAL_VERSION | $LAX_DOTTED_DECIMAL_VERSION /x;
+
+#--------------------------------------------------------------------------#
# Preloaded methods go here.
+sub import {
+ no strict 'refs';
+ my ($class) = shift;
+
+ # Set up any derived class
+ unless ($class eq 'version') {
+ local $^W;
+ *{$class.'::declare'} = \&version::declare;
+ *{$class.'::qv'} = \&version::qv;
+ }
+
+ my %args;
+ if (@_) { # any remaining terms are arguments
+ map { $args{$_} = 1 } @_
+ }
+ else { # no parameters at all on use line
+ %args =
+ (
+ qv => 1,
+ 'UNIVERSAL::VERSION' => 1,
+ );
+ }
+
+ my $callpkg = caller();
+
+ if (exists($args{declare})) {
+ *{$callpkg.'::declare'} =
+ sub {return $class->declare(shift) }
+ unless defined(&{$callpkg.'::declare'});
+ }
+
+ if (exists($args{qv})) {
+ *{$callpkg.'::qv'} =
+ sub {return $class->qv(shift) }
+ unless defined(&{$callpkg.'::qv'});
+ }
+
+ if (exists($args{'VERSION'})) {
+ *{$callpkg.'::VERSION'} = \&version::_VERSION;
+ }
+
+ if (exists($args{'is_strict'})) {
+ *{$callpkg.'::is_strict'} = \&version::is_strict;
+ }
+
+ if (exists($args{'is_lax'})) {
+ *{$callpkg.'::is_lax'} = \&version::is_lax;
+ }
+}
+
+sub is_strict { defined $_[0] && $_[0] =~ qr/ \A $STRICT \z /x }
+sub is_lax { defined $_[0] && $_[0] =~ qr/ \A $LAX \z /x }
1;