Copy scanner and parser to own packages.

pkg/dart_parser/lib/src/top_level_parser.dart

+// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library dart2js.parser.partial;
+
+import '../common.dart';
+import '../options.dart' show ParserOptions;
+import '../tokens/token.dart' show BeginGroupToken, ErrorToken, Token;
+import '../tokens/token_constants.dart' as Tokens show EOF_TOKEN;
+import '../util/characters.dart' as Characters show $CLOSE_CURLY_BRACKET;
+import 'listener.dart' show Listener;
+import 'parser.dart' show Parser;
+
+class PartialParser extends Parser {
+  PartialParser(Listener listener, ParserOptions options)
+      : super(listener, options);
+
+  Token parseClassBody(Token token) => skipClassBody(token);
+
+  Token fullParseClassBody(Token token) => super.parseClassBody(token);
+
+  Token parseExpression(Token token) => skipExpression(token);
+
+  Token parseArgumentsOpt(Token token) {
+    // This method is overridden for two reasons:
+    // 1. Avoid generating events for arguments.
+    // 2. Avoid calling skip expression for each argument (which doesn't work).
+    listener.handleNoArguments(token);
+    if (optional('(', token)) {
+      BeginGroupToken begin = token;
+      return begin.endGroup.next;
+    } else {
+      return token;
+    }
+  }
+
+  Token skipExpression(Token token) {
+    while (true) {
+      final kind = token.kind;
+      final value = token.stringValue;
+      if ((identical(kind, Tokens.EOF_TOKEN)) ||
+          (identical(value, ';')) ||
+          (identical(value, ',')) ||
+          (identical(value, '}')) ||
+          (identical(value, ')')) ||
+          (identical(value, ']'))) {
+        break;
+      }
+      if (identical(value, '=') ||
+          identical(value, '?') ||
+          identical(value, ':') ||
+          identical(value, '??')) {
+        var nextValue = token.next.stringValue;
+        if (identical(nextValue, 'const')) {
+          token = token.next;
+          nextValue = token.next.stringValue;
+        }
+        if (identical(nextValue, '{')) {
+          // Handle cases like this:
+          // class Foo {
+          //   var map;
+          //   Foo() : map = {};
+          //   Foo.x() : map = true ? {} : {};
+          // }
+          BeginGroupToken begin = token.next;
+          token = (begin.endGroup != null) ? begin.endGroup : token;
+          token = token.next;
+          continue;
+        }
+        if (identical(nextValue, '<')) {
+          // Handle cases like this:
+          // class Foo {
+          //   var map;
+          //   Foo() : map = <String, Foo>{};
+          //   Foo.x() : map = true ? <String, Foo>{} : <String, Foo>{};
+          // }
+          BeginGroupToken begin = token.next;
+          token = (begin.endGroup != null) ? begin.endGroup : token;
+          token = token.next;
+          if (identical(token.stringValue, '{')) {
+            begin = token;
+            token = (begin.endGroup != null) ? begin.endGroup : token;
+            token = token.next;
+          }
+          continue;
+        }
+      }
+      if (!mayParseFunctionExpressions && identical(value, '{')) {
+        break;
+      }
+      if (token is BeginGroupToken) {
+        BeginGroupToken begin = token;
+        token = (begin.endGroup != null) ? begin.endGroup : token;
+      } else if (token is ErrorToken) {
+        listener.reportErrorToken(token);
+      }
+      token = token.next;
+    }
+    return token;
+  }
+
+  Token skipClassBody(Token token) {
+    if (!optional('{', token)) {
+      return listener.expectedClassBodyToSkip(token);
+    }
+    BeginGroupToken beginGroupToken = token;
+    Token endGroup = beginGroupToken.endGroup;
+    if (endGroup == null) {
+      return listener.unmatched(beginGroupToken);
+    } else if (!identical(endGroup.kind, Characters.$CLOSE_CURLY_BRACKET)) {
+      return listener.unmatched(beginGroupToken);
+    }
+    return endGroup;
+  }
+
+  Token skipAsyncModifier(Token token) {
+    String value = token.stringValue;
+    if (identical(value, 'async')) {
+      token = token.next;
+      value = token.stringValue;
+
+      if (identical(value, '*')) {
+        token = token.next;
+      }
+    } else if (identical(value, 'sync')) {
+      token = token.next;
+      value = token.stringValue;
+
+      if (identical(value, '*')) {
+        token = token.next;
+      }
+    }
+    return token;
+  }
+
+  Token parseFunctionBody(Token token, bool isExpression, bool allowAbstract) {
+    assert(!isExpression);
+    token = skipAsyncModifier(token);
+    String value = token.stringValue;
+    if (identical(value, ';')) {
+      if (!allowAbstract) {
+        listener.reportError(token, MessageKind.BODY_EXPECTED);
+      }
+      listener.handleNoFunctionBody(token);
+    } else {
+      if (identical(value, '=>')) {
+        token = parseExpression(token.next);
+        expectSemicolon(token);
+      } else if (value == '=') {
+        token = parseRedirectingFactoryBody(token);
+        expectSemicolon(token);
+      } else {
+        token = skipBlock(token);
+      }
+      listener.skippedFunctionBody(token);
+    }
+    return token;
+  }
+
+  Token parseFormalParameters(Token token) => skipFormals(token);
+
+  Token skipFormals(Token token) {
+    listener.beginOptionalFormalParameters(token);
+    if (!optional('(', token)) {
+      if (optional(';', token)) {
+        listener.recoverableError(token, "expected '('");
+        return token;
+      }
+      return listener.unexpected(token);
+    }
+    BeginGroupToken beginGroupToken = token;
+    Token endToken = beginGroupToken.endGroup;
+    listener.endFormalParameters(0, token, endToken);
+    return endToken.next;
+  }
+}