Implemented Array.prototype.shift().

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

Author: dbatyai

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

@@ -397,6 +397,119 @@ ecma_builtin_array_prototype_object_index_of (ecma_value_t this_arg, /**< this a
   return ret_value;
 } /* ecma_builtin_array_prototype_object_index_of */
 
+/**
+ * The Array.prototype object's 'shift' routine
+ *
+ * See also:
+ *          ECMA-262 v5, 15.4.4.9
+ *
+ * @return completion value
+ *         Returned value must be freed with ecma_free_completion_value.
+ */
+static ecma_completion_value_t
+ecma_builtin_array_prototype_object_shift (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)
+  {
+    ECMA_TRY_CATCH (set_length_value,
+                    ecma_builtin_array_prototype_helper_set_length (obj_p, 0),
+                    ret_value);
+
+    ret_value = ecma_make_simple_completion_value (ECMA_SIMPLE_VALUE_UNDEFINED);
+
+    ECMA_FINALIZE (set_length_value);
+  }
+  else
+  {
+    ecma_string_t *index_str_p = ecma_new_ecma_string_from_uint32 (0);
+
+    /* 5. */
+    ECMA_TRY_CATCH (first_value, ecma_op_object_get (obj_p, index_str_p), ret_value);
+
+    /* 6. and 7. */
+    for (uint32_t k = 1; k < len && ecma_is_completion_value_empty (ret_value); k++)
+    {
+      /* 7.a */
+      ecma_string_t *from_str_p = ecma_new_ecma_string_from_uint32 (k);
+      /* 7.b */
+      ecma_string_t *to_str_p = ecma_new_ecma_string_from_uint32 (k - 1);
+
+      /* 7.c */
+      if (ecma_op_object_get_property (obj_p, from_str_p) != NULL)
+      {
+        /* 7.d.i */
+        ECMA_TRY_CATCH (curr_value, ecma_op_object_get (obj_p, from_str_p), ret_value);
+
+        /* 7.d.ii*/
+        ECMA_TRY_CATCH (put_value, ecma_op_object_put (obj_p, to_str_p, curr_value, true), ret_value);
+
+        ECMA_FINALIZE (put_value);
+        ECMA_FINALIZE (curr_value);
+      }
+      else
+      {
+        /* 7.e.i */
+        ECMA_TRY_CATCH (del_value, ecma_op_object_delete (obj_p, to_str_p, true), ret_value);
+        ECMA_FINALIZE (del_value);
+      }
+
+      ecma_deref_ecma_string (to_str_p);
+      ecma_deref_ecma_string (from_str_p);
+    }
+
+    if (ecma_is_completion_value_empty (ret_value))
+    {
+      len--;
+      ecma_string_t *index_str_p = ecma_new_ecma_string_from_uint32 (len);
+
+      /* 8. */
+      ECMA_TRY_CATCH (del_value, ecma_op_object_delete (obj_p, index_str_p, true), ret_value);
+
+      /* 9. */
+      ECMA_TRY_CATCH (set_length_value,
+                      ecma_builtin_array_prototype_helper_set_length (obj_p, len),
+                      ret_value);
+      /* 10. */
+      ret_value = ecma_make_normal_completion_value (ecma_copy_value (first_value, true));
+
+      ECMA_FINALIZE (set_length_value);
+      ECMA_FINALIZE (del_value);
+      ecma_deref_ecma_string (index_str_p);
+    }
+
+    ECMA_FINALIZE (first_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_shift */
+
 /**
  * @}
  * @}

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

@@ -62,6 +62,7 @@ ROUTINE (ECMA_MAGIC_STRING_TO_STRING_UL, ecma_builtin_array_prototype_object_to_
 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)
 ROUTINE (ECMA_MAGIC_STRING_INDEX_OF_UL, ecma_builtin_array_prototype_object_index_of, 2, 1)
+ROUTINE (ECMA_MAGIC_STRING_SHIFT, ecma_builtin_array_prototype_object_shift, 0, 0)
 
 #undef OBJECT_ID
 #undef SIMPLE_VALUE

tests/jerry/array_prototype_shift.js

@@ -0,0 +1,80 @@
+// 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.shift() === "foo");
+assert(array.length === 3);
+
+var a = array.shift();
+assert(a instanceof Array);
+assert(array.length === 2);
+
+assert(array.shift() === Infinity);
+assert(array.length === 1);
+
+assert(array.shift() === 4);
+assert(array.length === 0);
+
+assert(array.shift() === undefined);
+assert(array.length === 0);
+
+var referenceErrorThrower = function () {
+	throw new ReferenceError ("foo");
+}
+
+// Checking behavior when unable to get length
+var obj = { shift : Array.prototype.shift };
+Object.defineProperty(obj, 'length', { 'get' : referenceErrorThrower });
+
+try {
+	obj.shift();
+	assert(false);
+} catch (e) {
+	assert(e.message === "foo");
+	assert(e instanceof ReferenceError);
+}
+
+// Checking behavior when unable to set length
+var obj = { shift : Array.prototype.shift };
+Object.defineProperty(obj, 'length', { 'set' : referenceErrorThrower });
+
+try {
+	obj.shift();
+	assert(false);
+} catch (e) {
+	assert(e.message === "foo");
+	assert(e instanceof ReferenceError);
+}
+
+// Checking behavior when no length property defined
+var obj = { shift : Array.prototype.shift };
+assert (obj.length === undefined)
+assert (obj.shift() === undefined)
+assert (obj.length === 0)
+
+// Checking behavior when unable to get element
+var obj = { shift : Array.prototype.shift, length : 1 };
+Object.defineProperty(obj, '0', { 'get' : referenceErrorThrower });
+
+try {
+	obj.shift();
+	assert(false);
+} catch (e) {
+	assert(e.message === "foo");
+	assert(e instanceof ReferenceError);
+}