Implemented Array.prototype.pop().

JerryScript-DCO-1.0-Signed-off-by: Dániel Bátyai dbatyai.u-szeged@partner.samsung.com

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

@@ -44,6 +44,33 @@
  * @{
  */
 
+/**
+ * Helper function to set an object's length property
+ *
+ * @return completion value (return value of the [[Put]] method)
+ *         Returned value must be freed with ecma_free_completion_value.
+ */
+static ecma_completion_value_t
+ecma_builtin_array_prototype_helper_set_length (ecma_object_t *object, /**< object*/
+                                                uint32_t length) /**< new length */
+{
+  ecma_completion_value_t ret_value;
+  ecma_string_t *magic_string_length_p = ecma_get_magic_string (ECMA_MAGIC_STRING_LENGTH);
+
+  ecma_number_t *len_p = ecma_alloc_number ();
+  *len_p = ecma_uint32_to_number (length);
+
+  ret_value = ecma_op_object_put (object,
+                                  magic_string_length_p,
+                                  ecma_make_number_value (len_p),
+                                  true),
+
+  ecma_dealloc_number (len_p);
+  ecma_deref_ecma_string (magic_string_length_p);
+
+  return ret_value;
+} /* ecma_builtin_array_prototype_helper_set_length */
+
 /**
  * The Array.prototype object's 'toString' routine
  *
@@ -59,6 +86,85 @@ ecma_builtin_array_prototype_object_to_string (ecma_value_t this_arg) /**< this
   ECMA_BUILTIN_CP_UNIMPLEMENTED (this_arg);
 } /* ecma_builtin_array_prototype_object_to_string */
 
+/**
+ * The Array.prototype object's 'pop' routine
+ *
+ * See also:
+ *          ECMA-262 v5, 15.4.4.6
+ *
+ * @return completion value
+ *         Returned value must be freed with ecma_free_completion_value.
+ */
+static ecma_completion_value_t
+ecma_builtin_array_prototype_object_pop (ecma_value_t this_arg) /**< this argument */
+{
+  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 (len == 0)
+  {
+    /* 4.a */
+    ECMA_TRY_CATCH (set_length_value,
+                    ecma_builtin_array_prototype_helper_set_length (obj_p, 0),
+                    ret_value);
+
+    /* 4.b */
+    ret_value = ecma_make_simple_completion_value (ECMA_SIMPLE_VALUE_UNDEFINED);
+
+    ECMA_FINALIZE (set_length_value)
+  }
+  else
+  {
+    len--;
+    /* 5.a */
+    ecma_string_t *index_str_p = ecma_new_ecma_string_from_uint32 (len);
+
+    /* 5.b */
+    ECMA_TRY_CATCH (get_value, ecma_op_object_get (obj_p, index_str_p), ret_value);
+
+    /* 5.c */
+    ECMA_TRY_CATCH (del_value, ecma_op_object_delete (obj_p, index_str_p, true), ret_value);
+
+    /* 5.d */
+    ECMA_TRY_CATCH (set_length_value,
+                    ecma_builtin_array_prototype_helper_set_length (obj_p, len),
+                    ret_value);
+
+    ret_value = ecma_make_normal_completion_value (ecma_copy_value (get_value, true));
+
+    ECMA_FINALIZE (set_length_value);
+    ECMA_FINALIZE (del_value);
+    ECMA_FINALIZE (get_value);
+
+    ecma_deref_ecma_string (index_str_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_pop */
+
 /**
  * The Array.prototype object's 'push' routine
  *

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

@@ -59,6 +59,7 @@ NUMBER_VALUE (ECMA_MAGIC_STRING_LENGTH,
 /* Routine properties:
  *  (property name, C routine name, arguments number or NON_FIXED, value of the routine's length property) */
 ROUTINE (ECMA_MAGIC_STRING_TO_STRING_UL, ecma_builtin_array_prototype_object_to_string, 0, 0)
+ROUTINE (ECMA_MAGIC_STRING_POP, ecma_builtin_array_prototype_object_pop, 0, 0)
 ROUTINE (ECMA_MAGIC_STRING_PUSH, ecma_builtin_array_prototype_object_push, NON_FIXED, 1)
 
 #undef OBJECT_ID

tests/jerry/array_prototype_pop.js

@@ -0,0 +1,75 @@
+// 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.
+
+var array = ["foo", [], Infinity, 4]
+assert(array.length === 4);
+
+assert(array.pop() === 4)
+assert(array.length === 3);
+
+assert(array.pop() === Infinity);
+assert(array.length === 2);
+
+var a = array.pop()
+assert(a instanceof Array);
+assert(array.length === 1);
+
+assert(array.pop() === "foo");
+assert(array.length === 0);
+
+assert(array.pop() === undefined);
+assert(array.length === 0);
+
+// Checking behavior when unable to get length
+var obj = { pop : Array.prototype.pop };
+Object.defineProperty(obj, 'length', { 'get' : function () {throw new ReferenceError ("foo"); } });
+
+try {
+	obj.pop();
+	assert(false);
+} catch (e) {
+	assert(e.message === "foo");
+	assert(e instanceof ReferenceError);
+}
+
+// Checking behavior when unable to set length
+var obj = { pop : Array.prototype.pop };
+Object.defineProperty(obj, 'length', { 'set' : function () {throw new ReferenceError ("foo"); } });
+
+try {
+	obj.pop();
+	assert(false);
+} catch (e) {
+	assert(e.message === "foo");
+	assert(e instanceof ReferenceError);
+}
+
+// Checking behavior when no length property defined
+var obj = { pop : Array.prototype.pop };
+assert(obj.length === undefined)
+assert(obj.pop() === undefined)
+assert(obj.length === 0)
+
+// Checking behavior when unable to get element
+var obj = { pop : Array.prototype.pop, length : 1 };
+Object.defineProperty(obj, '0', { 'get' : function () {throw new ReferenceError ("foo"); } });
+
+try {
+	obj.pop();
+	assert(false);
+} catch (e) {
+	assert(e.message === "foo");
+	assert(e instanceof ReferenceError);
+}