jruby · Mar 10, 2015 · Mar 10, 2015
Showing with 46 additions and 20 deletions.

+0 −20 spec/truffle/tags/core/array/sample_tags.txt

+46 −0 truffle/src/main/ruby/core/rubinius/common/array.rb
diff --git a/spec/truffle/tags/core/array/sample_tags.txt b/spec/truffle/tags/core/array/sample_tags.txt
@@ -1,21 +1 @@
 fails:Array#sample returns nil for an empty Array
-fails:Array#sample returns a single value when not passed a count
-fails:Array#sample returns an empty Array when passed zero
-fails:Array#sample returns an Array of elements when passed a count
-fails:Array#sample returns elements from the Array
-fails:Array#sample returns at most the number of elements in the Array
-fails:Array#sample does not return the same value if the Array has unique values
-fails:Array#sample may return the same value if the array is not unique
-fails:Array#sample calls #to_int to convert the count when passed an Object
-fails:Array#sample raises ArgumentError when passed a negative count
-fails:Array#sample does not return subclass instances with Array subclass
-fails:Array#sample with options calls #to_hash to convert the passed Object
-fails:Array#sample with options calls #to_int on the first argument and #to_hash on the second when passed Objects
-fails:Array#sample with options calls #rand on the Object passed by the :random key in the arguments Hash
-fails:Array#sample with options ignores an Object passed for the RNG if it does not define #rand
-fails:Array#sample with options when the object returned by #rand is a Fixnum uses the fixnum as index
-fails:Array#sample with options when the object returned by #rand is a Fixnum raises a RangeError if the value is less than zero
-fails:Array#sample with options when the object returned by #rand is a Fixnum raises a RangeError if the value is equal to the Array size
-fails:Array#sample when the object returned by #rand is not a Fixnum but responds to #to_int calls #to_int on the Object
-fails:Array#sample when the object returned by #rand is not a Fixnum but responds to #to_int raises a RangeError if the value is less than zero
-fails:Array#sample when the object returned by #rand is not a Fixnum but responds to #to_int raises a RangeError if the value is equal to the Array size
diff --git a/truffle/src/main/ruby/core/rubinius/common/array.rb b/truffle/src/main/ruby/core/rubinius/common/array.rb
@@ -505,6 +505,52 @@ def rotate!(cnt=1)
     replace ary
   end
 
+  def sample(count=undefined, options=undefined)
+    return at Kernel.rand(size) if undefined.equal? count
+
+    if undefined.equal? options
+      if o = Rubinius::Type.check_convert_type(count, Hash, :to_hash)
+        options = o
+        count = nil
+      else
+        options = nil
+        count = Rubinius::Type.coerce_to_collection_index count
+      end
+    else
+      count = Rubinius::Type.coerce_to_collection_index count
+      options = Rubinius::Type.coerce_to options, Hash, :to_hash
+    end
+
+    if count and count < 0
+      raise ArgumentError, "count must be greater than 0"
+    end
+
+    rng = options[:random] if options
+    rng = Kernel unless rng and rng.respond_to? :rand
+
+    unless count
+      random = Rubinius::Type.coerce_to_collection_index rng.rand(size)
+      raise RangeError, "random value must be >= 0" if random < 0
+      raise RangeError, "random value must be less than Array size" unless random < size
+
+      return at random
+    end
+
+    count = size if count > size
+    result = Array.new self
+    tuple = Rubinius::Mirror::Array.reflect(result).tuple
+
+    count.times do |i|
+      random = Rubinius::Type.coerce_to_collection_index rng.rand(size)
+      raise RangeError, "random value must be >= 0" if random < 0
+      raise RangeError, "random value must be less than Array size" unless random < size
+
+      tuple.swap i, random
+    end
+
+    return count == size ? result : result[0, count]
+  end
+
   def find_index(obj=undefined)
     super
   end