Represent valgrind version numbers by their own class

[perl/modules/Test-Valgrind.git] / lib / Test / Valgrind / Version.pm

diff --git a/lib/Test/Valgrind/Version.pm b/lib/Test/Valgrind/Version.pm
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+++ b/lib/Test/Valgrind/Version.pm
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+package Test::Valgrind::Version;
+
+use strict;
+use warnings;
+
+=head1 NAME
+
+Test::Valgrind::Version - Object class for valgrind versions.
+
+=head1 VERSION
+
+Version 1.17
+
+=cut
+
+our $VERSION = '1.17';
+
+=head1 DESCRIPTION
+
+This class is used to parse, store and compare C<valgrind> versions.
+
+=cut
+
+use base 'Test::Valgrind::Carp';
+
+use Scalar::Util ();
+
+my $instanceof = sub {
+ Scalar::Util::blessed($_[0]) && $_[0]->isa($_[1]);
+};
+
+=head1 METHODS
+
+=head2 C<new>
+
+    my $vg_version = Test::Valgrind::Version->new(
+     command_output => qx{valgrind --version},
+    );
+
+    my $vg_version = Test::Valgrind::Version->new(
+     string => '1.2.3',
+    );
+
+Creates a new L<Test::Valgrind::Version> object representing a C<valgrind> version from one of these two sources :
+
+=over 4
+
+=item *
+
+if the C<command_output> option is specified, then C<new> will try to parse it as the output of C<valgrind --version>.
+
+=item *
+
+otherwise the C<string> option must be passed, and its value will be parsed as a 'dotted-integer' version number.
+
+=back
+
+An exception is raised if the version number cannot be inferred from the supplied data.
+
+=cut
+
+sub new {
+ my ($class, %args) = @_;
+
+ my $output = $args{command_output};
+ my $string;
+ if (defined $output) {
+  ($string) = $output =~ /^valgrind-([0-9]+(?:\.[0-9]+)*)(?!\.)/;
+ } else {
+  $string = $args{string};
+  return $string if $string->$instanceof(__PACKAGE__);
+  if (defined $string and $string =~ /^([0-9]+(?:\.[0-9]+)*)(?!\.)/) {
+   $string = $1;
+  } else {
+   $string = undef;
+  }
+ }
+ $class->_croak('Invalid argument') unless defined $string;
+
+ my @digits = map int, split /\./, $string;
+ my $last   = $#digits;
+ for my $i (reverse 0 .. $#digits) {
+  last if $digits[$i];
+  --$last;
+ }
+
+ bless {
+  _digits => [ @digits[0 .. $last] ],
+  _last   => $last,
+ }, $class;
+}
+
+BEGIN {
+ local $@;
+ eval "sub $_ { \$_[0]->{$_} }" for qw<_digits _last>;
+ die $@ if $@;
+}
+
+=head1 OVERLOADING
+
+This class overloads numeric comparison operators (C<< <=> >>, C<< < >>, C<< <= >>, C< == >, C<< => >> and C<< > >>), as well as stringification.
+
+=cut
+
+sub _spaceship {
+ my ($left, $right, $swap) = @_;
+
+ unless ($right->$instanceof(__PACKAGE__)) {
+  $right = __PACKAGE__->new(string => $right);
+ }
+ ($right, $left) = ($left, $right) if $swap;
+
+ my $left_digits  = $left->_digits;
+ my $right_digits = $right->_digits;
+
+ my $last_cmp = $left->_last <=> $right->_last;
+ my $last     = ($last_cmp < 0) ? $left->_last : $right->_last;
+
+ for my $i (0 .. $last) {
+  my $cmp = $left_digits->[$i] <=> $right_digits->[$i];
+  return $cmp if $cmp;
+ }
+
+ return $last_cmp;
+}
+
+sub _stringify {
+ my $self   = shift;
+ my @digits = @{ $self->_digits };
+ push @digits, 0 until @digits >= 3;
+ join '.', @digits;
+}
+
+use overload (
+ '<=>'    => \&_spaceship,
+ '""'     => \&_stringify,
+ fallback => 1,
+);
+
+=head1 SEE ALSO
+
+L<Test::Valgrind>.
+
+=head1 AUTHOR
+
+Vincent Pit, C<< <perl at profvince.com> >>, L<http://www.profvince.com>.
+
+You can contact me by mail or on C<irc.perl.org> (vincent).
+
+=head1 BUGS
+
+Please report any bugs or feature requests to C<bug-test-valgrind at rt.cpan.org>, or through the web interface at L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Test-Valgrind>.
+I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
+
+=head1 SUPPORT
+
+You can find documentation for this module with the perldoc command.
+
+    perldoc Test::Valgrind::Component
+
+=head1 COPYRIGHT & LICENSE
+
+Copyright 2015 Vincent Pit, all rights reserved.
+
+This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
+
+=cut
+
+1; # End of Test::Valgrind::Version