mruby-enum-lazy: add grep_v method

mrbgems/mruby-enum-lazy/mrblib/lazy.rb

@@ -10,6 +10,7 @@ module Enumerable
   #   - select    find_all
   #   - reject
   #   - grep
+  #   - grep_v
   #   - drop
   #   - drop_while
   #   - take_while
@@ -89,6 +90,14 @@ class Enumerator
       }
     end
 
+    def grep_v(pattern)
+      Lazy.new(self){|yielder, val|
+        unless pattern === val
+          yielder << val
+        end
+      }
+    end
+
     def drop(n)
       dropped = 0
       Lazy.new(self){|yielder, val|

mrbgems/mruby-enum-lazy/test/lazy.rb

@@ -46,6 +46,12 @@ assert("Enumerator::Lazy#to_enum") do
   assert_equal [0*1, 2*3, 4*5, 6*7], lazy_enum.map { |a| a.first * a.last }.first(4)
 end
 
+assert("Enumerator::Lazy#grep_v") do
+  lazy_grep_v = (0..).lazy.grep_v(2..4)
+  assert_kind_of Enumerator::Lazy, lazy_grep_v
+  assert_equal [0, 1, 5, 6], lazy_grep_v.first(4)
+end
+
 assert("Enumerator::Lazy#zip with cycle") do
   e1 = [1, 2, 3].cycle
   e2 = [:a, :b].cycle