| Subject: | Set::Infinite::intersected_spans fails on non-closed intervals |
Set::Infinite::intersected_spans doesn't work properly with non-closed
intervals. Look at the code, and follow this example:
$a1 = [....) [......................)
$b1 = $tmp = [....)
$before = [......]
$after = [........)
Now, ($tmp intersection $after) is empty, so what is returned is:
[............)
rather than the expected
[......................)
The commented out "optimization" in the source code behaves correctly in
this case, except the line
sub { return $_[0] if $_[0]->intersects( $b1 ) }
should read
sub { return $_[0] if $_[0]->intersects( $b1 ); undef }
This fixes the particular problem I'm having. Still,
something more needs doing when $a1 is too_complex.
Attatched is a patch against until.t from Set::Infinite 0.57 that adds a
few tests to catch the problem. Cheers.
--- until.t Mon Mar 15 19:25:21 2004
+++ /admin/olive07/until.t Mon Jun 14 15:34:18 2004
@@ -1,4 +1,4 @@
-#/bin/perl -w
+#!/bin/perl -w
# Copyright (c) 2001 Flavio Soibelmann Glock. All rights reserved.
# This program is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.
@@ -37,7 +37,7 @@
print " \n";
}
-print "1..34\n";
+print "1..38\n";
$| = 1;
# $Set::Infinite::TRACE = 1;
@@ -117,6 +117,23 @@
test ("intersected_spans - bounded to unbounded",
'$a->until( $b )->intersection(0,50)->intersected_spans($a)',
"[0..10),[20..30),[40..50)");
+test ("intersected_spans - half-open interval",
+ '$a->until( $b )->intersected_spans( Set::Infinite->new({ a=>5,
+ open_begin=>1, b=>45, open_end=>0 }) )',
+ "[0..10),[20..30),[40..50)");
+test ("intersected_spans - half-open interval",
+ '$a->until( $b )->intersected_spans( Set::Infinite->new({ a=>5,
+ open_begin=>0, b=>45, open_end=>1 }) )',
+ "[0..10),[20..30),[40..50)");
+test ("intersected_spans - bounded LHS with half-open interval",
+ 'Set::Infinite->new([0,20],[30,50],[60,80])->intersected_spans(
+ Set::Infinite->new({ a=>5, open_begin=>1, b=>45, open_end=>0 }) )',
+ "[0..20],[30..50]");
+test ("intersected_spans - bounded LHS with half-open interval",
+ 'Set::Infinite->new([0,20],[30,50],[60,80])->intersected_spans(
+ Set::Infinite->new({ a=>5, open_begin=>0, b=>45, open_end=>1 }) )',
+ "[0..20],[30..50]");
+
# let's test if contains() works properly with unbounded recurrences
# because we'll need that