require 'test/unit' class TestLazyEnumerator < Test::Unit::TestCase class Step include Enumerable attr_reader :current, :args def initialize(enum) @enum = enum @current = nil @args = nil end def each(*args) @args = args @enum.each {|i| @current = i; yield i} end end def test_initialize assert_equal([1, 2, 3], [1, 2, 3].lazy.to_a) assert_equal([1, 2, 3], Enumerator::Lazy.new([1, 2, 3]).to_a) end def test_each_args a = Step.new(1..3) assert_equal(1, a.lazy.each(4).first) assert_equal([4], a.args) end def test_each_line name = lineno = nil File.open(__FILE__) do |f| f.each("").map do |paragraph| paragraph[/\A\s*(.*)/, 1] end.find do |line| if name = line[/^class\s+(\S+)/, 1] lineno = f.lineno true end end end assert_equal(self.class.name, name) assert_operator(lineno, :>, 2) name = lineno = nil File.open(__FILE__) do |f| f.lazy.each("").map do |paragraph| paragraph[/\A\s*(.*)/, 1] end.find do |line| if name = line[/^class\s+(\S+)/, 1] lineno = f.lineno true end end end assert_equal(self.class.name, name) assert_equal(2, lineno) end def test_select a = Step.new(1..6) assert_equal(4, a.select {|x| x > 3}.first) assert_equal(6, a.current) assert_equal(4, a.lazy.select {|x| x > 3}.first) assert_equal(4, a.current) a = Step.new(['word', nil, 1]) assert_raise(TypeError) {a.select {|x| "x"+x}.first} assert_equal(nil, a.current) assert_equal("word", a.lazy.select {|x| "x"+x}.first) assert_equal("word", a.current) end def test_select_multiple_values e = Enumerator.new { |yielder| for i in 1..5 yielder.yield(i, i.to_s) end } assert_equal([[2, "2"], [4, "4"]], e.select {|x| x[0] % 2 == 0}) assert_equal([[2, "2"], [4, "4"]], e.lazy.select {|x| x[0] % 2 == 0}.force) end def test_map a = Step.new(1..3) assert_equal(2, a.map {|x| x * 2}.first) assert_equal(3, a.current) assert_equal(2, a.lazy.map {|x| x * 2}.first) assert_equal(1, a.current) end def test_flat_map a = Step.new(1..3) assert_equal(2, a.flat_map {|x| [x * 2]}.first) assert_equal(3, a.current) assert_equal(2, a.lazy.flat_map {|x| [x * 2]}.first) assert_equal(1, a.current) end def test_flat_map_nested a = Step.new(1..3) assert_equal([1, "a"], a.flat_map {|x| ("a".."c").map {|y| [x, y]}}.first) assert_equal(3, a.current) assert_equal([1, "a"], a.lazy.flat_map {|x| ("a".."c").lazy.map {|y| [x, y]}}.first) assert_equal(1, a.current) end def test_flat_map_to_ary to_ary = Class.new { def initialize(value) @value = value end def to_ary [:to_ary, @value] end } assert_equal([:to_ary, 1, :to_ary, 2, :to_ary, 3], [1, 2, 3].flat_map {|x| to_ary.new(x)}) assert_equal([:to_ary, 1, :to_ary, 2, :to_ary, 3], [1, 2, 3].lazy.flat_map {|x| to_ary.new(x)}.force) end def test_flat_map_non_array assert_equal(["1", "2", "3"], [1, 2, 3].flat_map {|x| x.to_s}) assert_equal(["1", "2", "3"], [1, 2, 3].lazy.flat_map {|x| x.to_s}.force) end def test_reject a = Step.new(1..6) assert_equal(4, a.reject {|x| x < 4}.first) assert_equal(6, a.current) assert_equal(4, a.lazy.reject {|x| x < 4}.first) assert_equal(4, a.current) a = Step.new(['word', nil, 1]) assert_equal(nil, a.reject {|x| x}.first) assert_equal(1, a.current) assert_equal(nil, a.lazy.reject {|x| x}.first) assert_equal(nil, a.current) end def test_reject_multiple_values e = Enumerator.new { |yielder| for i in 1..5 yielder.yield(i, i.to_s) end } assert_equal([[2, "2"], [4, "4"]], e.reject {|x| x[0] % 2 != 0}) assert_equal([[2, "2"], [4, "4"]], e.lazy.reject {|x| x[0] % 2 != 0}.force) end def test_grep a = Step.new('a'..'f') assert_equal('c', a.grep(/c/).first) assert_equal('f', a.current) assert_equal('c', a.lazy.grep(/c/).first) assert_equal('c', a.current) assert_equal(%w[a e], a.grep(proc {|x| /[aeiou]/ =~ x})) assert_equal(%w[a e], a.lazy.grep(proc {|x| /[aeiou]/ =~ x}).to_a) end def test_grep_with_block a = Step.new('a'..'f') assert_equal('C', a.grep(/c/) {|i| i.upcase}.first) assert_equal('C', a.lazy.grep(/c/) {|i| i.upcase}.first) end def test_grep_multiple_values e = Enumerator.new { |yielder| 3.times { |i| yielder.yield(i, i.to_s) } } assert_equal([[2, "2"]], e.grep(proc {|x| x == [2, "2"]})) assert_equal([[2, "2"]], e.lazy.grep(proc {|x| x == [2, "2"]}).force) assert_equal(["22"], e.lazy.grep(proc {|x| x == [2, "2"]}, &:join).force) end def test_zip a = Step.new(1..3) assert_equal([1, "a"], a.zip("a".."c").first) assert_equal(3, a.current) assert_equal([1, "a"], a.lazy.zip("a".."c").first) assert_equal(1, a.current) end def test_zip_short_arg a = Step.new(1..5) assert_equal([5, nil], a.zip("a".."c").last) assert_equal([5, nil], a.lazy.zip("a".."c").force.last) end def test_zip_without_arg a = Step.new(1..3) assert_equal([1], a.zip.first) assert_equal(3, a.current) assert_equal([1], a.lazy.zip.first) assert_equal(1, a.current) end def test_zip_with_block # zip should be eager when a block is given a = Step.new(1..3) ary = [] assert_equal(nil, a.lazy.zip("a".."c") {|x, y| ary << [x, y]}) assert_equal(a.zip("a".."c"), ary) assert_equal(3, a.current) end def test_take a = Step.new(1..10) assert_equal(1, a.take(5).first) assert_equal(5, a.current) assert_equal(1, a.lazy.take(5).first) assert_equal(1, a.current) assert_equal((1..5).to_a, a.lazy.take(5).force) assert_equal(5, a.current) a = Step.new(1..10) assert_equal([], a.lazy.take(0).force) assert_equal(nil, a.current) end def test_take_while a = Step.new(1..10) assert_equal(1, a.take_while {|i| i < 5}.first) assert_equal(5, a.current) assert_equal(1, a.lazy.take_while {|i| i < 5}.first) assert_equal(1, a.current) assert_equal((1..4).to_a, a.lazy.take_while {|i| i < 5}.to_a) end def test_drop a = Step.new(1..10) assert_equal(6, a.drop(5).first) assert_equal(10, a.current) assert_equal(6, a.lazy.drop(5).first) assert_equal(6, a.current) assert_equal((6..10).to_a, a.lazy.drop(5).to_a) end def test_drop_while a = Step.new(1..10) assert_equal(5, a.drop_while {|i| i < 5}.first) assert_equal(10, a.current) assert_equal(5, a.lazy.drop_while {|i| i < 5}.first) assert_equal(5, a.current) assert_equal((5..10).to_a, a.lazy.drop_while {|i| i < 5}.to_a) end def test_drop_and_take assert_equal([4, 5], (1..Float::INFINITY).lazy.drop(3).take(2).to_a) end def test_cycle a = Step.new(1..3) assert_equal("1", a.cycle(2).map(&:to_s).first) assert_equal(3, a.current) assert_equal("1", a.lazy.cycle(2).map(&:to_s).first) assert_equal(1, a.current) end def test_cycle_with_block # cycle should be eager when a block is given a = Step.new(1..3) ary = [] assert_equal(nil, a.lazy.cycle(2) {|i| ary << i}) assert_equal(a.cycle(2).to_a, ary) assert_equal(3, a.current) end def test_force assert_equal([1, 2, 3], (1..Float::INFINITY).lazy.take(3).force) end def test_inspect assert_equal("#", Enumerator::Lazy.new(1..10).inspect) assert_equal("#", Enumerator::Lazy.new(1..10, :cycle, 2).inspect) assert_equal("#", (1..10).lazy.inspect) assert_equal('#>', "foo".chars.lazy.inspect) assert_equal("#:map>", (1..10).lazy.map {}.inspect) assert_equal("#:take(0)>", (1..10).lazy.take(0).inspect) assert_equal("#:take(3)>", (1..10).lazy.take(3).inspect) assert_equal('#:grep(/b/)>', ("a".."c").lazy.grep(/b/).inspect) assert_equal("#:cycle(3)>", (1..10).lazy.cycle(3).inspect) assert_equal("#:cycle>", (1..10).lazy.cycle.inspect) assert_equal("#:cycle(3)>", (1..10).lazy.cycle(3).inspect) l = (1..10).lazy.map {}.collect {}.flat_map {}.collect_concat {}.select {}.find_all {}.reject {}.grep(1).zip(?a..?c).take(10).take_while {}.drop(3).drop_while {}.cycle(3) assert_equal(<:map>:collect>:flat_map>:collect_concat>:select>:find_all>:reject>:grep(1)>:zip("a".."c")>:take(10)>:take_while>:drop(3)>:drop_while>:cycle(3)> EOS end end