aboutsummaryrefslogtreecommitdiffstats
path: root/spec/ruby/core/array/repeated_permutation_spec.rb
diff options
context:
space:
mode:
authoreregon <eregon@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2017-09-20 20:18:52 +0000
committereregon <eregon@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2017-09-20 20:18:52 +0000
commit1d15d5f08032acf1b7bceacbb450d617ff6e0931 (patch)
treea3785a79899302bc149e4a6e72f624ac27dc1f10 /spec/ruby/core/array/repeated_permutation_spec.rb
parent75bfc6440d595bf339007f4fb280fd4d743e89c1 (diff)
downloadruby-1d15d5f08032acf1b7bceacbb450d617ff6e0931.tar.gz
Move spec/rubyspec to spec/ruby for consistency
* Other ruby implementations use the spec/ruby directory. [Misc #13792] [ruby-core:82287] git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59979 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'spec/ruby/core/array/repeated_permutation_spec.rb')
-rw-r--r--spec/ruby/core/array/repeated_permutation_spec.rb94
1 files changed, 94 insertions, 0 deletions
diff --git a/spec/ruby/core/array/repeated_permutation_spec.rb b/spec/ruby/core/array/repeated_permutation_spec.rb
new file mode 100644
index 0000000000..9038d49560
--- /dev/null
+++ b/spec/ruby/core/array/repeated_permutation_spec.rb
@@ -0,0 +1,94 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+
+
+describe "Array#repeated_permutation" do
+
+ before :each do
+ @numbers = [10, 11, 12]
+ @permutations = [[10, 10], [10, 11], [10, 12], [11, 10], [11, 11], [11, 12], [12, 10], [12, 11], [12, 12]]
+ end
+
+ it "returns an Enumerator of all repeated permutations of given length when called without a block" do
+ enum = @numbers.repeated_permutation(2)
+ enum.should be_an_instance_of(Enumerator)
+ enum.to_a.sort.should == @permutations
+ end
+
+ it "yields all repeated_permutations to the block then returns self when called with block but no arguments" do
+ yielded = []
+ @numbers.repeated_permutation(2) {|n| yielded << n}.should equal(@numbers)
+ yielded.sort.should == @permutations
+ end
+
+ it "yields the empty repeated_permutation ([[]]) when the given length is 0" do
+ @numbers.repeated_permutation(0).to_a.should == [[]]
+ [].repeated_permutation(0).to_a.should == [[]]
+ end
+
+ it "does not yield when called on an empty Array with a nonzero argument" do
+ [].repeated_permutation(10).to_a.should == []
+ end
+
+ it "handles duplicate elements correctly" do
+ @numbers[-1] = 10
+ @numbers.repeated_permutation(2).sort.should ==
+ [[10, 10], [10, 10], [10, 10], [10, 10], [10, 11], [10, 11], [11, 10], [11, 10], [11, 11]]
+ end
+
+ it "truncates Float arguments" do
+ @numbers.repeated_permutation(3.7).to_a.sort.should ==
+ @numbers.repeated_permutation(3).to_a.sort
+ end
+
+ it "returns an Enumerator which works as expected even when the array was modified" do
+ @numbers.shift
+ enum = @numbers.repeated_permutation(2)
+ @numbers.unshift 10
+ enum.to_a.sort.should == @permutations
+ end
+
+ it "allows permutations larger than the number of elements" do
+ [1,2].repeated_permutation(3).sort.should ==
+ [[1, 1, 1], [1, 1, 2], [1, 2, 1],
+ [1, 2, 2], [2, 1, 1], [2, 1, 2],
+ [2, 2, 1], [2, 2, 2]]
+ end
+
+ it "generates from a defensive copy, ignoring mutations" do
+ accum = []
+ ary = [1,2]
+ ary.repeated_permutation(3) do |x|
+ accum << x
+ ary[0] = 5
+ end
+
+ accum.sort.should ==
+ [[1, 1, 1], [1, 1, 2], [1, 2, 1],
+ [1, 2, 2], [2, 1, 1], [2, 1, 2],
+ [2, 2, 1], [2, 2, 2]]
+ end
+
+ describe "when no block is given" do
+ describe "returned Enumerator" do
+ describe "size" do
+ it "returns 0 when combination_size is < 0" do
+ @numbers.repeated_permutation(-1).size.should == 0
+ [].repeated_permutation(-1).size.should == 0
+ end
+
+ it "returns array size ** combination_size" do
+ @numbers.repeated_permutation(4).size.should == 81
+ @numbers.repeated_permutation(3).size.should == 27
+ @numbers.repeated_permutation(2).size.should == 9
+ @numbers.repeated_permutation(1).size.should == 3
+ @numbers.repeated_permutation(0).size.should == 1
+ [].repeated_permutation(4).size.should == 0
+ [].repeated_permutation(3).size.should == 0
+ [].repeated_permutation(2).size.should == 0
+ [].repeated_permutation(1).size.should == 0
+ [].repeated_permutation(0).size.should == 1
+ end
+ end
+ end
+ end
+end