Initial Commit

database/perl/vendor/lib/Number/Compare.pm

@@ -0,0 +1,99 @@
+package Number::Compare;
+use strict;
+use Carp qw(croak);
+use vars qw/$VERSION/;
+$VERSION = '0.03';
+
+sub new  {
+    my $referent = shift;
+    my $class = ref $referent || $referent;
+    my $expr = $class->parse_to_perl( shift );
+
+    bless eval "sub { \$_[0] $expr }", $class;
+}
+
+sub parse_to_perl {
+    shift;
+    my $test = shift;
+
+    $test =~ m{^
+               ([<>]=?)?   # comparison
+               (.*?)       # value
+               ([kmg]i?)?  # magnitude
+              $}ix
+       or croak "don't understand '$test' as a test";
+
+    my $comparison = $1 || '==';
+    my $target     = $2;
+    my $magnitude  = $3 || '';
+    $target *=           1000 if lc $magnitude eq 'k';
+    $target *=           1024 if lc $magnitude eq 'ki';
+    $target *=        1000000 if lc $magnitude eq 'm';
+    $target *=      1024*1024 if lc $magnitude eq 'mi';
+    $target *=     1000000000 if lc $magnitude eq 'g';
+    $target *= 1024*1024*1024 if lc $magnitude eq 'gi';
+
+    return "$comparison $target";
+}
+
+sub test { $_[0]->( $_[1] ) }
+
+1;
+
+__END__
+
+=head1 NAME
+
+Number::Compare - numeric comparisons
+
+=head1 SYNOPSIS
+
+ Number::Compare->new(">1Ki")->test(1025); # is 1025 > 1024
+
+ my $c = Number::Compare->new(">1M");
+ $c->(1_200_000);                          # slightly terser invocation
+
+=head1 DESCRIPTION
+
+Number::Compare compiles a simple comparison to an anonymous
+subroutine, which you can call with a value to be tested again.
+
+Now this would be very pointless, if Number::Compare didn't understand
+magnitudes.
+
+The target value may use magnitudes of kilobytes (C<k>, C<ki>),
+megabytes (C<m>, C<mi>), or gigabytes (C<g>, C<gi>).  Those suffixed
+with an C<i> use the appropriate 2**n version in accordance with the
+IEC standard: http://physics.nist.gov/cuu/Units/binary.html
+
+=head1 METHODS
+
+=head2 ->new( $test )
+
+Returns a new object that compares the specified test.
+
+=head2 ->test( $value )
+
+A longhanded version of $compare->( $value ).  Predates blessed
+subroutine reference implementation.
+
+=head2 ->parse_to_perl( $test )
+
+Returns a perl code fragment equivalent to the test.
+
+=head1 AUTHOR
+
+Richard Clamp <richardc@unixbeard.net>
+
+=head1 COPYRIGHT
+
+Copyright (C) 2002,2011 Richard Clamp.  All Rights Reserved.
+
+This module is free software; you can redistribute it and/or modify it
+under the same terms as Perl itself.
+
+=head1 SEE ALSO
+
+http://physics.nist.gov/cuu/Units/binary.html
+
+=cut