Implement binding pattern support for rest argument and for statement. (#3327)

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

jerry-core/parser/js/js-lexer.c

@@ -1406,6 +1406,28 @@ lexer_check_next_character (parser_context_t *context_p, /**< context */
           && context_p->source_p[0] == (uint8_t) character);
 } /* lexer_check_next_character */
 
+/**
+ * Checks whether the next token starts with either specified characters.
+ *
+ * @return true - if the next is the specified character
+ *         false - otherwise
+ */
+bool
+lexer_check_next_characters (parser_context_t *context_p, /**< context */
+                             lit_utf8_byte_t character1, /**< first alternative character */
+                             lit_utf8_byte_t character2) /**< second alternative character */
+{
+  if (!(context_p->token.flags & LEXER_NO_SKIP_SPACES))
+  {
+    lexer_skip_spaces (context_p);
+    context_p->token.flags = (uint8_t) (context_p->token.flags | LEXER_NO_SKIP_SPACES);
+  }
+
+  return (context_p->source_p < context_p->source_end_p
+          && (context_p->source_p[0] == (uint8_t) character1
+              || context_p->source_p[0] == (uint8_t) character2));
+} /* lexer_check_next_characters */
+
 #if ENABLED (JERRY_ES2015)
 
 /**

jerry-core/parser/js/js-parser-expr.c

@@ -1446,8 +1446,7 @@ parser_parse_unary_expression (parser_context_t *context_p, /**< context */
     }
     case LEXER_KEYW_SUPER:
     {
-      if ((lexer_check_next_character (context_p, LIT_CHAR_DOT)
+      if (lexer_check_next_characters (context_p, LIT_CHAR_DOT, LIT_CHAR_LEFT_SQUARE)
-            || lexer_check_next_character (context_p, LIT_CHAR_LEFT_SQUARE))
           && context_p->status_flags & (PARSER_CLASS_HAS_SUPER))
       {
         if (!LEXER_IS_BINARY_LVALUE_TOKEN (context_p->stack_top_uint8))

jerry-core/parser/js/js-parser-internal.h

@@ -615,6 +615,8 @@ void parser_set_continues_to_current_position (parser_context_t *context_p, pars
 
 void lexer_next_token (parser_context_t *context_p);
 bool lexer_check_next_character (parser_context_t *context_p, lit_utf8_byte_t character);
+bool lexer_check_next_characters (parser_context_t *context_p, lit_utf8_byte_t character1,
+                                  lit_utf8_byte_t character2);
 #if ENABLED (JERRY_ES2015)
 void lexer_skip_empty_statements (parser_context_t *context_p);
 bool lexer_check_arrow (parser_context_t *context_p);

jerry-core/parser/js/js-parser-statm.c

@@ -496,8 +496,7 @@ parser_parse_var_statement (parser_context_t *context_p) /**< context */
   while (true)
   {
 #if ENABLED (JERRY_ES2015)
-    if (lexer_check_next_character (context_p, LIT_CHAR_LEFT_BRACE)
+    if (lexer_check_next_characters (context_p, LIT_CHAR_LEFT_SQUARE, LIT_CHAR_LEFT_BRACE))
-        || lexer_check_next_character (context_p, LIT_CHAR_LEFT_SQUARE))
     {
       lexer_next_token (context_p);
       parser_pattern_flags_t options = PARSER_PATTERN_BINDING;
@@ -1199,14 +1198,40 @@ parser_parse_for_statement_start (parser_context_t *context_p) /**< context */
 #endif /* ENABLED (JERRY_ES2015) */
       case LEXER_KEYW_VAR:
       {
-        uint16_t literal_index;
+#if ENABLED (JERRY_ES2015)
+        if (lexer_check_next_characters (context_p, LIT_CHAR_LEFT_SQUARE, LIT_CHAR_LEFT_BRACE))
+        {
+          bool is_lexical = (context_p->token.type != LEXER_KEYW_VAR);
+
+          lexer_next_token (context_p);
+
+          parser_emit_cbc_ext (context_p, is_for_in ? CBC_EXT_FOR_IN_GET_NEXT
+                                                    : CBC_EXT_FOR_OF_GET_NEXT);
+
+          if (context_p->next_scanner_info_p->source_p == context_p->source_p)
+          {
+            JERRY_ASSERT (context_p->next_scanner_info_p->type == SCANNER_TYPE_INITIALIZER);
+
+            scanner_release_next (context_p, sizeof (scanner_location_info_t));
+          }
+
+          uint32_t flags = (PARSER_PATTERN_BINDING | PARSER_PATTERN_TARGET_ON_STACK);
+
+          if (is_lexical)
+          {
+            flags |= PARSER_PATTERN_LEXICAL;
+          }
+
+          parser_parse_initializer (context_p, (parser_pattern_flags_t) flags);
+          break;
+        }
+#endif /* ENABLED (JERRY_ES2015) */
 
         lexer_expect_identifier (context_p, LEXER_IDENT_LITERAL);
         JERRY_ASSERT (context_p->token.type == LEXER_LITERAL
                       && context_p->token.lit_location.type == LEXER_IDENT_LITERAL);
 
-        literal_index = context_p->lit_object.index;
+        uint16_t literal_index = context_p->lit_object.index;
-
         lexer_next_token (context_p);
 
         if (context_p->token.type == LEXER_ASSIGN)

jerry-core/parser/js/js-parser.c

@@ -1638,7 +1638,7 @@ parser_parse_function_arguments (parser_context_t *context_p, /**< context */
     }
     else if (context_p->token.type == LEXER_THREE_DOTS)
     {
-      lexer_expect_identifier (context_p, LEXER_IDENT_LITERAL);
+      lexer_next_token (context_p);
 
       if (duplicated_argument_names)
       {
@@ -1647,7 +1647,8 @@ parser_parse_function_arguments (parser_context_t *context_p, /**< context */
 
       context_p->status_flags |= PARSER_FUNCTION_HAS_REST_PARAM | PARSER_FUNCTION_HAS_NON_SIMPLE_PARAM;
     }
-    else if (context_p->token.type == LEXER_LEFT_SQUARE || context_p->token.type == LEXER_LEFT_BRACE)
+
+    if (context_p->token.type == LEXER_LEFT_SQUARE || context_p->token.type == LEXER_LEFT_BRACE)
     {
       if (duplicated_argument_names)
       {
@@ -1668,6 +1669,12 @@ parser_parse_function_arguments (parser_context_t *context_p, /**< context */
       if (context_p->next_scanner_info_p->source_p == context_p->source_p)
       {
         JERRY_ASSERT (context_p->next_scanner_info_p->type == SCANNER_TYPE_INITIALIZER);
+
+        if (context_p->status_flags & PARSER_FUNCTION_HAS_REST_PARAM)
+        {
+          parser_raise_error (context_p, PARSER_ERR_REST_PARAMETER_DEFAULT_INITIALIZER);
+        }
+
         flags |= PARSER_PATTERN_TARGET_DEFAULT;
       }
 

jerry-core/parser/js/js-scanner.c

@@ -2439,11 +2439,11 @@ scanner_scan_all (parser_context_t *context_p, /**< context */
           {
             uint8_t binding_type = SCANNER_BINDING_VAR;
 
-            if (stack_top == SCAN_STACK_LET)
+            if (stack_top == SCAN_STACK_LET || stack_top == SCAN_STACK_FOR_LET_START)
             {
               binding_type = SCANNER_BINDING_LET;
             }
-            else if (stack_top == SCAN_STACK_CONST)
+            else if (stack_top == SCAN_STACK_CONST || stack_top == SCAN_STACK_FOR_CONST_START)
             {
               binding_type = SCANNER_BINDING_CONST;
             }

tests/jerry/es2015/for-pattern.js

@@ -0,0 +1,77 @@
+// Copyright JS Foundation and other contributors, http://js.foundation
+//
+// 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 idx = 0;
+for (var [a,b] of [[1,2], [3,4]])
+{
+  if (idx == 0)
+  {
+    assert(a === 1);
+    assert(b === 2);
+    idx = 1;
+  }
+  else
+  {
+    assert(a === 3);
+    assert(b === 4);
+  }
+}
+
+assert(a === 3);
+assert(b === 4);
+
+idx = 0;
+for (let [a,b] of [[5,6], [7,8]])
+{
+  if (idx == 0)
+  {
+    assert(a === 5);
+    assert(b === 6);
+    idx = 1;
+  }
+  else
+  {
+    assert(a === 7);
+    assert(b === 8);
+  }
+}
+
+assert(a === 3);
+assert(b === 4);
+
+idx = 0;
+for (let [a,b] of [[11,12], [13,14]])
+{
+  if (idx == 0)
+  {
+    eval("assert(a === 11)");
+    eval("assert(b === 12)");
+    idx = 1;
+  }
+  else
+  {
+    eval("assert(a === 13)");
+    eval("assert(b === 14)");
+  }
+}
+
+assert(a === 3);
+assert(b === 4);
+
+try {
+  eval("for (let [a,b] = [1,2] of [[3,4]]) {}");
+  assert(false);
+} catch (e) {
+  assert(e instanceof SyntaxError);
+}

tests/jerry/es2015/function-pattern1.js

@@ -30,6 +30,7 @@ must_throw ("function f([a], a) {}");
 must_throw ("function f(a = b, [b]) {}; f()", ReferenceError);
 must_throw ("function f([a+b]) {}");
 must_throw ("function f([a().b]) {}");
+must_throw ("function f(...[a] = [1]) {}");
 
 function a1([a,b]) {
   var a, b;

tests/jerry/es2015/function-pattern2.js

@@ -59,3 +59,12 @@ function k([a = function() { return a; }])
   assert(a() === a);
 }
 k([]);
+
+function l(a = 0, ...[b, c = 1, d = 4])
+{
+  assert(a === 1);
+  assert(b === 2);
+  assert(c === 3);
+  assert(d === 4);
+}
+l(1,2,3);