add mruby-enum-lazy mrbgem for Enumerable::Lazy

1 files changed, 47 insertions, 0 deletions

diff --git a/mrbgems/mruby-enum-lazy/test/lazy.rb b/mrbgems/mruby-enum-lazy/test/lazy.rb
new file mode 100644
index 000000000..ca009d34c
--- /dev/null
+++ b/mrbgems/mruby-enum-lazy/test/lazy.rb
@@ -0,0 +1,47 @@
+assert("Enumerable::Lazy") do
+  a = [1, 2]
+  assert_equal Enumerable::Lazy, a.lazy.class
+end
+
+assert("Enumerable::Lazy laziness") do
+  a = Object.new
+  def a.each
+    return to_enum :each unless block_given?
+    self.b << 10
+    yield 1
+    self.b << 20
+    yield 2
+    self.b << 30
+    yield 3
+    self.b << 40
+    yield 4
+    self.b << 50
+    yield 5
+  end
+  def a.b(b=nil)
+    @b = b if b
+    @b
+  end
+
+  a.b([])
+  assert_equal [1,2], a.each.lazy.take(2).force
+  assert_equal [10,20], a.b
+
+  a.b([])
+  assert_equal [2,4], a.each.lazy.select{|x|x%2==0}.take(2).force
+  assert_equal [10,20,30,40], a.b
+
+  a.b([])
+  assert_equal [1], a.each.lazy.take_while{|x|x<2}.take(1).force
+  assert_equal [10], a.b
+
+  a.b([])
+  assert_equal [1], a.each.lazy.take_while{|x|x<2}.take(4).force
+  assert_equal [10,20], a.b
+end
+
+assert("Enumerable::Lazy#zip with cycle") do
+  e1 = [1, 2, 3].cycle
+  e2 = [:a, :b].cycle
+  assert_equal [[1,:a],[2,:b],[3,:a]], e1.lazy.zip(e2).first(3)
+end