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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], Enumerable::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_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_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_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_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_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
a = Step.new(1..3)
assert_equal(["a", 1], a.lazy.zip("a".."c") {|x, y| [y, x]}.first)
assert_equal(1, 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).to_a)
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_force
assert_equal([1, 2, 3], (1..Float::INFINITY).lazy.take(3).force)
end
end
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