require "spec_helper" require "hamster/vector" describe Hamster::Vector do let(:vector) { V[1,2,3,4] } let(:big) { V.new(1..10000) } [:slice, :[]].each do |method| describe "##{method}" do context "when passed a positive integral index" do it "returns the element at that index" do vector.send(method, 0).should be(1) vector.send(method, 1).should be(2) vector.send(method, 2).should be(3) vector.send(method, 3).should be(4) vector.send(method, 4).should be(nil) vector.send(method, 10).should be(nil) big.send(method, 0).should be(1) big.send(method, 9999).should be(10000) end it "leaves the original unchanged" do vector.should eql(V[1,2,3,4]) end end context "when passed a negative integral index" do it "returns the element which is number (index.abs) counting from the end of the vector" do vector.send(method, -1).should be(4) vector.send(method, -2).should be(3) vector.send(method, -3).should be(2) vector.send(method, -4).should be(1) vector.send(method, -5).should be(nil) vector.send(method, -10).should be(nil) big.send(method, -1).should be(10000) big.send(method, -10000).should be(1) end end context "when passed a positive integral index and count" do it "returns 'count' elements starting from 'index'" do vector.send(method, 0, 0).should eql(V.empty) vector.send(method, 0, 1).should eql(V[1]) vector.send(method, 0, 2).should eql(V[1,2]) vector.send(method, 0, 4).should eql(V[1,2,3,4]) vector.send(method, 0, 6).should eql(V[1,2,3,4]) vector.send(method, 0, -1).should be_nil vector.send(method, 0, -2).should be_nil vector.send(method, 0, -4).should be_nil vector.send(method, 2, 0).should eql(V.empty) vector.send(method, 2, 1).should eql(V[3]) vector.send(method, 2, 2).should eql(V[3,4]) vector.send(method, 2, 4).should eql(V[3,4]) vector.send(method, 2, -1).should be_nil vector.send(method, 4, 0).should eql(V.empty) vector.send(method, 4, 2).should eql(V.empty) vector.send(method, 4, -1).should be_nil vector.send(method, 5, 0).should be_nil vector.send(method, 5, 2).should be_nil vector.send(method, 5, -1).should be_nil vector.send(method, 6, 0).should be_nil vector.send(method, 6, 2).should be_nil vector.send(method, 6, -1).should be_nil big.send(method, 0, 3).should eql(V[1,2,3]) big.send(method, 1023, 4).should eql(V[1024,1025,1026,1027]) big.send(method, 1024, 4).should eql(V[1025,1026,1027,1028]) end it "leaves the original unchanged" do vector.should eql(V[1,2,3,4]) end end context "when passed a negative integral index and count" do it "returns 'count' elements, starting from index which is number 'index.abs' counting from the end of the array" do vector.send(method, -1, 0).should eql(V.empty) vector.send(method, -1, 1).should eql(V[4]) vector.send(method, -1, 2).should eql(V[4]) vector.send(method, -1, -1).should be_nil vector.send(method, -2, 0).should eql(V.empty) vector.send(method, -2, 1).should eql(V[3]) vector.send(method, -2, 2).should eql(V[3,4]) vector.send(method, -2, 4).should eql(V[3,4]) vector.send(method, -2, -1).should be_nil vector.send(method, -4, 0).should eql(V.empty) vector.send(method, -4, 1).should eql(V[1]) vector.send(method, -4, 2).should eql(V[1,2]) vector.send(method, -4, 4).should eql(V[1,2,3,4]) vector.send(method, -4, 6).should eql(V[1,2,3,4]) vector.send(method, -4, -1).should be_nil vector.send(method, -5, 0).should be_nil vector.send(method, -5, 1).should be_nil vector.send(method, -5, 10).should be_nil vector.send(method, -5, -1).should be_nil big.send(method, -1, 1).should eql(V[10000]) big.send(method, -1, 2).should eql(V[10000]) big.send(method, -6, 2).should eql(V[9995,9996]) end end context "when passed a Range" do it "returns the elements whose indexes are within the given Range" do vector.send(method, 0..-1).should eql(V[1,2,3,4]) vector.send(method, 0..-10).should eql(V.empty) vector.send(method, 0..0).should eql(V[1]) vector.send(method, 0..1).should eql(V[1,2]) vector.send(method, 0..2).should eql(V[1,2,3]) vector.send(method, 0..3).should eql(V[1,2,3,4]) vector.send(method, 0..4).should eql(V[1,2,3,4]) vector.send(method, 0..10).should eql(V[1,2,3,4]) vector.send(method, 2..-10).should eql(V.empty) vector.send(method, 2..0).should eql(V.empty) vector.send(method, 2..2).should eql(V[3]) vector.send(method, 2..3).should eql(V[3,4]) vector.send(method, 2..4).should eql(V[3,4]) vector.send(method, 3..0).should eql(V.empty) vector.send(method, 3..3).should eql(V[4]) vector.send(method, 3..4).should eql(V[4]) vector.send(method, 4..0).should eql(V.empty) vector.send(method, 4..4).should eql(V.empty) vector.send(method, 4..5).should eql(V.empty) vector.send(method, 5..0).should be_nil vector.send(method, 5..5).should be_nil vector.send(method, 5..6).should be_nil big.send(method, 159..162).should eql(V[160,161,162,163]) big.send(method, 160..162).should eql(V[161,162,163]) big.send(method, 161..162).should eql(V[162,163]) big.send(method, 9999..10100).should eql(V[10000]) big.send(method, 10000..10100).should eql(V.empty) big.send(method, 10001..10100).should be_nil vector.send(method, 0...-1).should eql(V[1,2,3]) vector.send(method, 0...-10).should eql(V.empty) vector.send(method, 0...0).should eql(V.empty) vector.send(method, 0...1).should eql(V[1]) vector.send(method, 0...2).should eql(V[1,2]) vector.send(method, 0...3).should eql(V[1,2,3]) vector.send(method, 0...4).should eql(V[1,2,3,4]) vector.send(method, 0...10).should eql(V[1,2,3,4]) vector.send(method, 2...-10).should eql(V.empty) vector.send(method, 2...0).should eql(V.empty) vector.send(method, 2...2).should eql(V.empty) vector.send(method, 2...3).should eql(V[3]) vector.send(method, 2...4).should eql(V[3,4]) vector.send(method, 3...0).should eql(V.empty) vector.send(method, 3...3).should eql(V.empty) vector.send(method, 3...4).should eql(V[4]) vector.send(method, 4...0).should eql(V.empty) vector.send(method, 4...4).should eql(V.empty) vector.send(method, 4...5).should eql(V.empty) vector.send(method, 5...0).should be_nil vector.send(method, 5...5).should be_nil vector.send(method, 5...6).should be_nil big.send(method, 159...162).should eql(V[160,161,162]) big.send(method, 160...162).should eql(V[161,162]) big.send(method, 161...162).should eql(V[162]) big.send(method, 9999...10100).should eql(V[10000]) big.send(method, 10000...10100).should eql(V.empty) big.send(method, 10001...10100).should be_nil vector.send(method, -1..-1).should eql(V[4]) vector.send(method, -1...-1).should eql(V.empty) vector.send(method, -1..3).should eql(V[4]) vector.send(method, -1...3).should eql(V.empty) vector.send(method, -1..4).should eql(V[4]) vector.send(method, -1...4).should eql(V[4]) vector.send(method, -1..10).should eql(V[4]) vector.send(method, -1...10).should eql(V[4]) vector.send(method, -1..0).should eql(V.empty) vector.send(method, -1..-4).should eql(V.empty) vector.send(method, -1...-4).should eql(V.empty) vector.send(method, -1..-6).should eql(V.empty) vector.send(method, -1...-6).should eql(V.empty) vector.send(method, -2..-2).should eql(V[3]) vector.send(method, -2...-2).should eql(V.empty) vector.send(method, -2..-1).should eql(V[3,4]) vector.send(method, -2...-1).should eql(V[3]) vector.send(method, -2..10).should eql(V[3,4]) vector.send(method, -2...10).should eql(V[3,4]) big.send(method, -1..-1).should eql(V[10000]) big.send(method, -1..9999).should eql(V[10000]) big.send(method, -1...9999).should eql(V.empty) big.send(method, -2...9999).should eql(V[9999]) big.send(method, -2..-1).should eql(V[9999,10000]) vector.send(method, -4..-4).should eql(V[1]) vector.send(method, -4..-2).should eql(V[1,2,3]) vector.send(method, -4...-2).should eql(V[1,2]) vector.send(method, -4..-1).should eql(V[1,2,3,4]) vector.send(method, -4...-1).should eql(V[1,2,3]) vector.send(method, -4..3).should eql(V[1,2,3,4]) vector.send(method, -4...3).should eql(V[1,2,3]) vector.send(method, -4..4).should eql(V[1,2,3,4]) vector.send(method, -4...4).should eql(V[1,2,3,4]) vector.send(method, -4..0).should eql(V[1]) vector.send(method, -4...0).should eql(V.empty) vector.send(method, -4..1).should eql(V[1,2]) vector.send(method, -4...1).should eql(V[1]) vector.send(method, -5..-5).should be_nil vector.send(method, -5...-5).should be_nil vector.send(method, -5..-4).should be_nil vector.send(method, -5..-1).should be_nil vector.send(method, -5..10).should be_nil big.send(method, -10001..-1).should be_nil end it "leaves the original unchanged" do vector.should eql(V[1,2,3,4]) end end end context "when passed a subclass of Range" do it "works the same as with a Range" do subclass = Class.new(Range) vector.send(method, subclass.new(1,2)).should eql(V[2,3]) vector.send(method, subclass.new(-3,-1,true)).should eql(V[2,3]) end end context "on a subclass of Vector" do it "with index and count or a range, returns an instance of the subclass" do subclass = Class.new(Hamster::Vector) instance = subclass.new([1,2,3]) instance.send(method, 0, 0).class.should be(subclass) instance.send(method, 0, 2).class.should be(subclass) instance.send(method, 0..0).class.should be(subclass) instance.send(method, 1..-1).class.should be(subclass) end end end end