require 'matrix'

ruby_version_is "1.9.1" do
  describe "Matrix#each_with_index" do
    before :all do
      @m = Matrix[ [1, 2, 3], [4, 5, 6] ]
      @result = [
        [1, 0, 0],
        [2, 0, 1],
        [3, 0, 2],
        [4, 1, 0],
        [5, 1, 1],
        [6, 1, 2]
      ]
    end

    it "returns an Enumerator when called without a block" do
      enum = @m.each_with_index
      enum.should be_an_instance_of(enumerator_class)
      enum.to_a.should == @result
    end

    it "returns self" do
      @m.each_with_index{}.should equal(@m)
    end

    it "yields the elements starting with the those of the first row" do
      a = []
      @m.each_with_index {|x, r, c| a << [x, r, c]}
      a.should == @result
    end
  end
end

ruby_version_is "1.9.3" do
  describe "Matrix#each_with_index with an argument" do
    before :all do
      @m = Matrix[ [1, 2, 3, 4], [5, 6, 7, 8] ]
      @t = Matrix[ [1, 2], [3, 4], [5, 6], [7, 8] ]
    end

    it "raises an ArgumentError for unrecognized argument" do
      lambda {
        @m.each_with_index("all"){}
      }.should raise_error(ArgumentError)
      lambda {
        @m.each_with_index(nil){}
      }.should raise_error(ArgumentError)
      lambda {
        @m.each_with_index(:left){}
      }.should raise_error(ArgumentError)
    end

    it "yields the rights elements when passed :diagonal" do
      @m.each_with_index(:diagonal).to_a.should == [[1, 0, 0], [6, 1, 1]]
      @t.each_with_index(:diagonal).to_a.should == [[1, 0, 0], [4, 1, 1]]
    end

    it "yields the rights elements when passed :off_diagonal" do
      @m.each_with_index(:off_diagonal).to_a.should == [[2, 0, 1], [3, 0, 2], [4, 0, 3], [5, 1, 0], [7, 1, 2], [8, 1, 3]]
      @t.each_with_index(:off_diagonal).to_a.should == [[2, 0, 1], [3, 1, 0], [5, 2, 0], [6, 2, 1], [7, 3, 0], [8, 3, 1]]
    end

    it "yields the rights elements when passed :lower" do
      @m.each_with_index(:lower).to_a.should == [[1, 0, 0], [5, 1, 0], [6, 1, 1]]
      @t.each_with_index(:lower).to_a.should == [[1, 0, 0], [3, 1, 0], [4, 1, 1], [5, 2, 0], [6, 2, 1], [7, 3, 0], [8, 3, 1]]
    end

    it "yields the rights elements when passed :strict_lower" do
      @m.each_with_index(:strict_lower).to_a.should == [[5, 1, 0]]
      @t.each_with_index(:strict_lower).to_a.should == [[3, 1, 0], [5, 2, 0], [6, 2, 1], [7, 3, 0], [8, 3, 1]]
    end

    it "yields the rights elements when passed :strict_upper" do
      @m.each_with_index(:strict_upper).to_a.should == [[2, 0, 1], [3, 0, 2], [4, 0, 3], [7, 1, 2], [8, 1, 3]]
      @t.each_with_index(:strict_upper).to_a.should == [[2, 0, 1]]
    end

    it "yields the rights elements when passed :upper" do
      @m.each_with_index(:upper).to_a.should == [[1, 0, 0], [2, 0, 1], [3, 0, 2], [4, 0, 3], [6, 1, 1], [7, 1, 2], [8, 1, 3]]
      @t.each_with_index(:upper).to_a.should == [[1, 0, 0], [2, 0, 1], [4, 1, 1]]
    end
  end
end
