Implemented Array.prototype.filter()

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

@@ -1521,6 +1521,130 @@ ecma_builtin_array_prototype_object_some (ecma_value_t this_arg, /**< this argum
   return ret_value;
 } /* ecma_builtin_array_prototype_object_some */
 
+/**
+ * The Array.prototype object's 'filter' routine
+ *
+ * See also:
+ *          ECMA-262 v5, 15.4.4.20
+ *
+ * @return completion value
+ *         Returned value must be freed with ecma_free_completion_value.
+ */
+static ecma_completion_value_t
+ecma_builtin_array_prototype_object_filter (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);
+
+  /* 3. */
+  ECMA_OP_TO_NUMBER_TRY_CATCH (len_number, len_value, ret_value);
+
+  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_value_t current_index;
+    ecma_number_t *num_p = ecma_alloc_number ();
+    ecma_object_t *func_object_p;
+
+    /* 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);
+
+    /* We already checked that arg1 is callable, so it will always be an object. */
+    JERRY_ASSERT (ecma_is_value_object (arg1));
+    func_object_p = ecma_get_object_from_value (arg1);
+
+    /* 8. */
+    uint32_t new_array_index = 0;
+
+    /* 9. */
+    for (uint32_t index = 0; index < len && ecma_is_completion_value_empty (ret_value); index++)
+    {
+      /* 9.a */
+      ecma_string_t *index_str_p = ecma_new_ecma_string_from_uint32 (index);
+
+      /* 9.c */
+      if (ecma_op_object_get_property (obj_p, index_str_p) != NULL)
+      {
+        /* 9.c.i */
+        ECMA_TRY_CATCH (get_value, ecma_op_object_get (obj_p, index_str_p), ret_value);
+
+        *num_p = ecma_uint32_to_number (index);
+        current_index = ecma_make_number_value (num_p);
+
+        ecma_value_t call_args[] = { get_value, current_index, obj_this };
+        /* 9.c.ii */
+        ECMA_TRY_CATCH (call_value, ecma_op_function_call (func_object_p, arg2, call_args, 3), ret_value);
+
+        /* 9.c.iii, ecma_op_to_boolean always returns a simple value, so no need to free. */
+        if (ecma_is_value_true (ecma_op_to_boolean (call_value)))
+        {
+          ecma_string_t* to_index_string_p = ecma_new_ecma_string_from_uint32 (new_array_index);
+          /*
+           * 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_completion_value_t put_comp_value = ecma_op_object_put (new_array_p,
+                                                                       to_index_string_p,
+                                                                       get_value,
+                                                                       false);
+          JERRY_ASSERT (ecma_is_completion_value_normal_true (put_comp_value));
+          ecma_free_completion_value (put_comp_value);
+
+          ecma_deref_ecma_string (to_index_string_p);
+          new_array_index++;
+        }
+
+        ECMA_FINALIZE (call_value);
+        ECMA_FINALIZE (get_value);
+      }
+
+      ecma_deref_ecma_string (index_str_p);
+    }
+
+    ecma_dealloc_number (num_p);
+
+    if (ecma_is_completion_value_empty (ret_value))
+    {
+      /* 10. */
+      ret_value = new_array;
+    }
+    else
+    {
+      ecma_free_completion_value (new_array);
+    }
+  }
+
+  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_filter */
+
 /**
  * The Array.prototype object's 'slice' routine
  *

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

@@ -74,6 +74,7 @@ ROUTINE (ECMA_MAGIC_STRING_EVERY, ecma_builtin_array_prototype_object_every, 2,
 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)
 
 #undef OBJECT_ID
 #undef SIMPLE_VALUE

tests/jerry/array_prototype_filter.js

@@ -0,0 +1,72 @@
+// 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]
+
+function f(arg1, arg2, arg3) {
+	assert(arg1 === array[arg2]);
+	assert(arg3 === array);
+	return true;
+}
+
+var filtered = array.filter(f);
+assert(filtered.length === array.length);
+for (i = 0; i < filtered.length; i++) {
+	assert(filtered[i] === array[i]);
+}
+
+var array = [1, 2, 3, 4, 5, 6, 7, 8];
+
+function g (arg1, arg2, arg3) {
+	if (arg2 % 2 === 0) {
+		return true;
+	} else {
+		return false;
+	}
+}
+
+filtered = array.filter(g)
+assert(filtered.length === 4);
+assert(filtered[0] === 1);
+assert(filtered[1] === 3);
+assert(filtered[2] === 5);
+assert(filtered[3] === 7);
+
+// Checking behavior when unable to get length
+var obj = {};
+Object.defineProperty(obj, 'length', { 'get' : function () {throw new ReferenceError ("foo"); } });
+obj.filter = Array.prototype.filter;
+
+try {
+	obj.filter(f);
+	assert(false);
+} catch (e) {
+	assert(e.message === "foo");
+	assert(e instanceof ReferenceError);
+}
+
+// Checking behavior when unable to get element
+var obj = {}
+obj.length = 1;
+Object.defineProperty(obj, '0', { 'get' : function () {throw new ReferenceError ("foo"); } });
+obj.filter = Array.prototype.filter
+
+try {
+	obj.filter(f);
+	assert(false);
+} catch (e) {
+	assert(e.message === "foo");
+	assert(e instanceof ReferenceError);
+}