Ruby < 1.8.7 doesn't have this method and we're using it in a test, so tests won't run on 1.8.6 until this is in place.
It's probably a good thing to use much in implementation since it's written in pure Ruby when using < 1.8.7 and in C when in > 1.8.7, but then if you're using older Rubies you're probably not expecting much for performance anyway. Reviewed-by: Daniel Pittman <dan...@puppetlabs.com> Signed-off-by: Matt Robinson <m...@puppetlabs.com> --- Local-branch: ticket/next/maint-backport_array_combination lib/puppet/util/monkey_patches.rb | 14 ++++++++++++++ spec/unit/util/monkey_patches_spec.rb | 23 +++++++++++++++++++++++ 2 files changed, 37 insertions(+), 0 deletions(-) diff --git a/lib/puppet/util/monkey_patches.rb b/lib/puppet/util/monkey_patches.rb index a93c66b..10a2684 100644 --- a/lib/puppet/util/monkey_patches.rb +++ b/lib/puppet/util/monkey_patches.rb @@ -90,3 +90,17 @@ if RUBY_VERSION == '1.8.1' || RUBY_VERSION == '1.8.2' r } end + +class Array + # Ruby < 1.8.7 doesn't have this method but we use it in tests + def combination(num) + return [] if num < 0 || num > size + return [[]] if num == 0 + return map{|e| [e] } if num == 1 + tmp = self.dup + self[0, size - (num - 1)].inject([]) do |ret, e| + tmp.shift + ret += tmp.combination(num - 1).map{|a| a.unshift(e) } + end + end unless method_defined? :combination +end diff --git a/spec/unit/util/monkey_patches_spec.rb b/spec/unit/util/monkey_patches_spec.rb index 8bfcd90..fb2103e 100644 --- a/spec/unit/util/monkey_patches_spec.rb +++ b/spec/unit/util/monkey_patches_spec.rb @@ -31,3 +31,26 @@ describe "yaml deserialization" do obj.foo.should == 100 end end + +# In Ruby > 1.8.7 this is a builtin, otherwise we monkey patch the method in +describe "Array#combination" do + it "should fail if wrong number of arguments given" do + lambda { [1,2,3].combination() }.should raise_error(ArgumentError, /wrong number/) + lambda { [1,2,3].combination(1,2) }.should raise_error(ArgumentError, /wrong number/) + end + + it "should return an empty array if combo size than array size or negative" do + [1,2,3].combination(4).to_a.should == [] + [1,2,3].combination(-1).to_a.should == [] + end + + it "should return an empty array with an empty array if combo size == 0" do + [1,2,3].combination(0).to_a.should == [[]] + end + + it "should all provide all combinations of size passed in" do + [1,2,3,4].combination(1).to_a.should == [[1], [2], [3], [4]] + [1,2,3,4].combination(2).to_a.should == [[1, 2], [1, 3], [1, 4], [2, 3], [2, 4], [3, 4]] + [1,2,3,4].combination(3).to_a.should == [[1, 2, 3], [1, 2, 4], [1, 3, 4], [2, 3, 4]] + end +end -- 1.7.3.1 -- You received this message because you are subscribed to the Google Groups "Puppet Developers" group. To post to this group, send email to puppet-dev@googlegroups.com. To unsubscribe from this group, send email to puppet-dev+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/puppet-dev?hl=en.