Merge pull request #500 from rlevick/enumerable

Enumerable#take, Enumerable#take_while, Enumerable#reject

lib-topaz/enumerable.rb

@@ -56,6 +56,7 @@ def include?(obj)
     end
     false
   end
+  alias member? include?
 
   def drop(n)
     raise ArgumentError.new("attempt to drop negative size") if n < 0
@@ -83,6 +84,7 @@ def to_a
     end
     result
   end
+  alias entries to_a
 
   def detect(ifnone = nil, &block)
     self.each do |o|
@@ -91,4 +93,33 @@ def detect(ifnone = nil, &block)
     return ifnone
   end
   alias find detect
+
+  def take(n)
+    raise ArgumentError.new("attempt to take negative size") if n < 0
+    result = []
+    unless n == 0
+      self.each do |o|
+        result << o
+        break if result.size == n
+      end
+    end
+    result
+  end
+
+  def take_while(&block)
+    result = []
+    self.each do |o|
+      break unless yield(o)
+      result << o
+    end
+    result
+  end
+
+  def reject(&block)
+    result = []
+    self.each do |o|
+      result << o unless yield(o)
+    end
+    result
+  end
 end

spec/tags/core/enumerable/entries_tags.txt

@@ -1,3 +1,2 @@
-fails:Enumerable#entries returns an array containing the elements
 fails:Enumerable#entries passes through the values yielded by #each_with_index
 fails:Enumerable#entries passes arguments to each

spec/tags/core/enumerable/member_tags.txt

@@ -1,4 +1 @@
-fails:Enumerable#member? returns true if any element == argument for numbers
-fails:Enumerable#member? returns true if any element == argument for other objects
-fails:Enumerable#member? returns true if any member of enum equals obj when == compare different classes (legacy rubycon)
 fails:Enumerable#member? gathers whole arrays as elements when each yields multiple

spec/tags/core/enumerable/reject_tags.txt

@@ -1,3 +1,2 @@
-fails:Enumerable#reject returns an array of the elements for which block is false
 fails:Enumerable#reject returns an Enumerator if called without a block
 fails:Enumerable#reject gathers whole arrays as elements when each yields multiple

spec/tags/core/enumerable/take_tags.txt

@@ -1,11 +1,3 @@
-fails:Enumerable#take requires an argument
-fails:Enumerable#take when passed an argument returns the first count elements if given a count
-fails:Enumerable#take when passed an argument returns an empty array when passed count on an empty array
-fails:Enumerable#take when passed an argument returns an empty array when passed count == 0
-fails:Enumerable#take when passed an argument returns an array containing the first element when passed count == 1
-fails:Enumerable#take when passed an argument raises an ArgumentError when count is negative
-fails:Enumerable#take when passed an argument returns the entire array when count > length
 fails:Enumerable#take when passed an argument tries to convert the passed argument to an Integer using #to_int
 fails:Enumerable#take when passed an argument raises a TypeError if the passed argument is not numeric
 fails:Enumerable#take when passed an argument gathers whole arrays as elements when each yields multiple
-fails:Enumerable#take when passed an argument consumes only what is needed

spec/tags/core/enumerable/take_while_tags.txt

@@ -1,6 +1 @@
 fails:Enumerable#take_while returns an Enumerator if no block given
-fails:Enumerable#take_while returns no/all elements for {true/false} block
-fails:Enumerable#take_while accepts returns other than true/false
-fails:Enumerable#take_while passes elements to the block until the first false
-fails:Enumerable#take_while will only go through what's needed
-fails:Enumerable#take_while doesn't return self when it could

tests/modules/test_enumerable.py

@@ -152,3 +152,31 @@ def test_map(self, space):
         assert self.unwrap(space, w_res) == [x for x in range(2, 7)]
         w_res = space.execute("return [1,2,3,4,5].collect { |i| i + 1 }")
         assert self.unwrap(space, w_res) == [x for x in range(2, 7)]
+
+    def test_take(self, space):
+        w_res = space.execute("return [1,2,3,4,5].take(2)")
+        assert self.unwrap(space, w_res) == [1, 2]
+        w_res = space.execute("return [1,2,3,4,5].take(0)")
+        assert self.unwrap(space, w_res) == []
+        w_res = space.execute("return [].take(2)")
+        assert self.unwrap(space, w_res) == []
+
+    def test_take_while(self, space):
+        w_res = space.execute("return (1..10).take_while { |i| i < 4 }")
+        assert self.unwrap(space, w_res) == [1, 2, 3]
+        w_res = space.execute("return [].take_while { |i| i == 11 }")
+        assert self.unwrap(space, w_res) == []
+        w_res = space.execute("return (1..10).take_while { |i| i > 11 }")
+        assert self.unwrap(space, w_res) == []
+        w_res = space.execute("return (1..10).take_while { |i| i < 11 }")
+        assert self.unwrap(space, w_res) == [x for x in range(1, 11)]
+
+    def test_reject(self, space):
+        w_res = space.execute("return [1, 2, 3].reject { |i| i == 3 }")
+        assert self.unwrap(space, w_res) == [1, 2]
+        w_res = space.execute("return [].reject { |i| i == 3 }")
+        assert self.unwrap(space, w_res) == []
+        w_res = space.execute("return (1..10).reject { |i| i > 11 }")
+        assert self.unwrap(space, w_res) == [x for x in range(1, 11)]
+        w_res = space.execute("return (1..10).reject { |i| i < 11 }")
+        assert self.unwrap(space, w_res) == []