Array.prototype.map()

JerryScript-DCO-1.0-Signed-off-by: Laszlo Vidacs [email protected]

Author: lvidacs

jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype.cpp

@@ -2452,6 +2452,114 @@ ecma_builtin_array_prototype_object_splice (ecma_value_t this_arg, /**< this arg
   return ret_value;
 } /* ecma_builtin_array_prototype_object_splice */
 
+/**
+ * The Array.prototype object's 'map' routine
+ *
+ * See also:
+ *          ECMA-262 v5, 15.4.4.19
+ *
+ * @return completion value
+ *         Returned value must be freed with ecma_free_completion_value.
+ */
+static ecma_completion_value_t
+ecma_builtin_array_prototype_object_map (ecma_value_t this_arg, /**< this argument */
+                                         ecma_value_t arg1, /**< callbackfn */
+                                         ecma_value_t arg2) /**< thisArg */
+{
+  ecma_completion_value_t ret_value = ecma_make_empty_completion_value ();
+
+  /* 1 */
+  ECMA_TRY_CATCH (obj_this,
+                  ecma_op_to_object (this_arg),
+                  ret_value);
+
+  ecma_object_t *obj_p = ecma_get_object_from_value (obj_this);
+  ecma_string_t *magic_string_length_p = ecma_get_magic_string (ECMA_MAGIC_STRING_LENGTH);
+
+  /* 2 */
+  ECMA_TRY_CATCH (len_value,
+                  ecma_op_object_get (obj_p, magic_string_length_p),
+                  ret_value);
+
+  ECMA_OP_TO_NUMBER_TRY_CATCH (len_number, len_value, ret_value);
+
+  /* 3 */
+  uint32_t len = ecma_number_to_uint32 (len_number);
+
+  /* 4 */
+  if (!ecma_op_is_callable (arg1))
+  {
+    ret_value = ecma_make_throw_obj_completion_value (ecma_new_standard_error (ECMA_ERROR_TYPE));
+  }
+  else
+  {
+    ecma_number_t *num_p = ecma_alloc_number ();
+    ecma_object_t *func_object_p;
+    JERRY_ASSERT (ecma_is_value_object (arg1));
+    func_object_p = ecma_get_object_from_value (arg1);
+
+    /* 5: arg2 is simply used as T */
+
+    /* 6 */
+    ecma_completion_value_t new_array = ecma_op_create_array_object (NULL, 0, false);
+    JERRY_ASSERT (ecma_is_completion_value_normal (new_array));
+    ecma_object_t *new_array_p = ecma_get_object_from_completion_value (new_array);
+
+    /* 7-8 */
+    ecma_value_t current_index;
+
+    for (uint32_t index = 0; index < len && ecma_is_completion_value_empty (ret_value); ++index)
+    {
+      /* 8a */
+      ecma_string_t *index_str_p = ecma_new_ecma_string_from_uint32 (index);
+      /* 8b */
+      if (ecma_op_object_get_property (obj_p, index_str_p) != NULL)
+      {
+        /* 8c-i */
+        ECMA_TRY_CATCH (current_value, ecma_op_object_get (obj_p, index_str_p), ret_value);
+        /* 8c-ii */
+        *num_p = ecma_uint32_to_number (index);
+        current_index = ecma_make_number_value (num_p);
+        ecma_value_t call_args[] = {current_value, current_index, obj_this};
+
+        ECMA_TRY_CATCH (mapped_value, ecma_op_function_call (func_object_p, arg2, call_args, 3), ret_value);
+
+        /* 8c-iii
+         * By definition we should use [[DefineOwnProperty]] here, but since [[Put]] will create the
+         * same property that we need, we can use it for simplicity. No need for a try-catch block
+         * since it is called with is_throw = false.
+         * ecma_op_to_boolean always returns a simple value, so no need to free.
+        */
+        ecma_completion_value_t put_comp_value = ecma_op_object_put (new_array_p, index_str_p, mapped_value, false);
+        JERRY_ASSERT (ecma_is_completion_value_normal_true (put_comp_value));
+        ecma_free_completion_value (put_comp_value);
+
+        ECMA_FINALIZE (mapped_value);
+        ECMA_FINALIZE (current_value);
+      }
+
+      ecma_deref_ecma_string (index_str_p);
+    }
+
+    if (ecma_is_completion_value_empty (ret_value))
+    {
+      ret_value = new_array;
+    }
+    else
+    {
+      ecma_free_completion_value (new_array);
+    }
+
+    ecma_dealloc_number (num_p);
+  }
+
+  ECMA_OP_TO_NUMBER_FINALIZE (len_number);
+  ECMA_FINALIZE (len_value);
+  ecma_deref_ecma_string (magic_string_length_p);
+  ECMA_FINALIZE (obj_this);
+
+  return ret_value;
+} /* ecma_builtin_array_prototype_object_map */
 
 /**
  * The Array.prototype object's 'reduce' routine

jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype.inc.h

@@ -76,6 +76,7 @@ ROUTINE (ECMA_MAGIC_STRING_SOME, ecma_builtin_array_prototype_object_some, 2, 1)
 ROUTINE (ECMA_MAGIC_STRING_SLICE, ecma_builtin_array_prototype_object_slice, 2, 2)
 ROUTINE (ECMA_MAGIC_STRING_SPLICE, ecma_builtin_array_prototype_object_splice, NON_FIXED, 2)
 ROUTINE (ECMA_MAGIC_STRING_FILTER, ecma_builtin_array_prototype_object_filter, 2, 1)
+ROUTINE (ECMA_MAGIC_STRING_MAP, ecma_builtin_array_prototype_object_map, 2, 1)
 ROUTINE (ECMA_MAGIC_STRING_REDUCE, ecma_builtin_array_prototype_object_reduce, 2, 1)
 
 #undef OBJECT_ID

tests/jerry/array_prototype_map.js

@@ -0,0 +1,101 @@
+// Copyright 2015 Samsung Electronics Co., Ltd.
+// Copyright 2015 University of Szeged.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// helper function - simple implementation
+Array.prototype.equals = function (array) {
+  if (this.length != array.length)
+    return false;
+
+  for (var i = 0; i < this.length; i++) {
+    if (this[i] instanceof Array && array[i] instanceof Array) {
+      if (!this[i].equals(array[i]))
+        return false;
+      }
+      else if (this[i] != array[i]) {
+        return false;
+    }
+  }
+
+  return true;
+}
+
+// check function type
+try {
+  [0].map(new Object());
+  assert(false);
+} catch(e) {
+  assert(e instanceof TypeError);
+}
+
+// various checks
+assert ([1, 4, 9].map(Math.sqrt).equals([1, 2, 3]));
+
+assert (isNaN([1, 4, "X"].map(Number)[2]));
+
+var func = function(val, idx) {
+  return val + idx;
+};
+
+assert ([1, 4, 9].map(func).equals([1,5,11]));
+
+assert ([1, "X", 10].map(func).equals([1, "X1", 12]));
+
+var long_array = [0, 1];
+assert (long_array.map(func).equals([0,2]));
+
+long_array[100] = 1;
+assert (long_array.map(func).equals([0,2,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,101]));
+
+// check behavior when unable to get length
+var obj = {};
+Object.defineProperty(obj, 'length', { 'get' : function () {throw new ReferenceError ("foo"); } });
+obj.map = Array.prototype.map;
+
+try {
+  obj.map(func);
+  assert(false);
+} catch (e) {
+  assert(e.message === "foo");
+  assert(e instanceof ReferenceError);
+}
+
+// check behavior when unable to get element
+var obj = {}
+obj.length = 1;
+Object.defineProperty(obj, '0', { 'get' : function () {throw new ReferenceError ("foo"); } });
+obj.map = Array.prototype.map
+
+try {
+  obj.map(func);
+  assert(false);
+} catch (e) {
+  assert(e.message === "foo");
+  assert(e instanceof ReferenceError);
+}
+
+// check thisArg
+var thisArg = {add: 10};
+var func2 = function(value) {
+  return this.add + value;
+}
+assert([1,2].map(func2, thisArg).equals([11, 12]));
+
+// check passed Object
+var array_example = [1,2];
+Object.defineProperty(array_example, 'const', { 'get' : function () {return "CT";} });
+var func3 = function(value, idx, thisobj) {
+  return value * idx + thisobj.const;
+}
+assert(array_example.map(func3).equals(["0CT", "2CT"]));