unfork DDC's copy of most SDK libraries

pkg/dev_compiler/tool/input_sdk/lib/internal/symbol.dart

-// Copyright (c) 2013, 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.
-
-part of dart._internal;
-
-/**
- * Implementation of [core.Symbol].  This class uses the same name as
- * a core class so a user can't tell the difference.
- *
- * The purpose of this class is to hide [_name] from user code, but
- * make it accessible to Dart platform code via the static method
- * [getName].
- */
-class Symbol implements core.Symbol {
-  final String _name;
-
-  // Used internally by DDC to map ES6 symbols to Dart.
-  final dynamic _nativeSymbol;
-
-  /**
-   * Source of RegExp matching Dart reserved words.
-   *
-   * Reserved words are not allowed as identifiers.
-   */
-  static const String reservedWordRE =
-      r'(?:assert|break|c(?:a(?:se|tch)|lass|on(?:st|tinue))|d(?:efault|o)|'
-      r'e(?:lse|num|xtends)|f(?:alse|inal(?:ly)?|or)|i[fns]|n(?:ew|ull)|'
-      r'ret(?:hrow|urn)|s(?:uper|witch)|t(?:h(?:is|row)|r(?:ue|y))|'
-      r'v(?:ar|oid)|w(?:hile|ith))';
-  /**
-   * Source of RegExp matching any public identifier.
-   *
-   * A public identifier is a valid identifier (not a reserved word)
-   * that doesn't start with '_'.
-   */
-  static const String publicIdentifierRE =
-      r'(?!' '$reservedWordRE' r'\b(?!\$))[a-zA-Z$][\w$]*';
-  /**
-   * Source of RegExp matching any identifier.
-   *
-   * It matches identifiers but not reserved words. The identifiers
-   * may start with '_'.
-   */
-  static const String identifierRE =
-      r'(?!' '$reservedWordRE' r'\b(?!\$))[a-zA-Z$_][\w$]*';
-  /**
-   * Source of RegExp matching a declarable operator names.
-   *
-   * The operators that can be declared using `operator` declarations are
-   * also the only ones allowed as symbols. The name of the oeprators is
-   * the same as the operator itself except for unary minus, where the name
-   * is "unary-".
-   */
-  static const String operatorRE =
-      r'(?:[\-+*/%&|^]|\[\]=?|==|~/?|<[<=]?|>[>=]?|unary-)';
-
-  // Grammar if symbols:
-  //    symbol ::= qualifiedName | <empty>
-  //    qualifiedName ::= publicIdentifier '.' qualifiedName | name
-  //    name ::= publicIdentifier
-  //           | publicIdentifier '='
-  //           | operator
-  // where publicIdentifier is any valid identifier (not a reserved word)
-  // that isn't private (doesn't start with '_').
-  //
-  // Railroad diagram of the accepted grammar:
-  //
-  //    /----------------\
-  //    |                |
-  //    |          /-[.]-/     /-[=]-\
-  //    \         /           /       \
-  //  -------[id]------------------------->
-  //       \                     /
-  //        \------[operator]---/
-  //            \              /
-  //             \------------/
-  //
-
-  /**
-   * RegExp that validates a non-empty non-private symbol.
-   *
-   * The empty symbol is handled before this regexp is used, and is not
-   * accepted.
-   */
-  static final RegExp publicSymbolPattern = new RegExp(
-      '^(?:$operatorRE\$|$publicIdentifierRE(?:=?\$|[.](?!\$)))+?\$');
-
-  // The grammar of symbols that may be private is the same as for public
-  // symbols, except that "publicIdentifier" is replaced by "identifier",
-  // which matches any identifier.
-
-  /**
-   * RegExp that validates a non-empty symbol.
-   *
-   * Private symbols are accepted.
-   *
-   * The empty symbol is handled before this regexp is used, and is not
-   * accepted.
-   */
-  static final RegExp symbolPattern =
-      new RegExp('^(?:$operatorRE\$|$identifierRE(?:=?\$|[.](?!\$)))+?\$');
-
-  external const Symbol(String name);
-
-  external const Symbol.es6(String name, nativeSymbol);
-
-  /**
-   * Platform-private method used by the mirror system to create
-   * otherwise invalid names.
-   */
-  const Symbol.unvalidated(this._name) : this._nativeSymbol = null;
-
-  // This is called by dart2js.
-  Symbol.validated(String name)
-      : this._name = validatePublicSymbol(name),
-        this._nativeSymbol = null;
-
-  bool operator ==(Object other) =>
-      other is Symbol &&
-      _name == other._name &&
-      _nativeSymbol == other._nativeSymbol;
-
-  external int get hashCode;
-
-  toString() => 'Symbol("$_name")';
-
-  /// Platform-private accessor which cannot be called from user libraries.
-  static String getName(Symbol symbol) => symbol._name;
-
-  static dynamic getNativeSymbol(Symbol symbol) => symbol._nativeSymbol;
-
-  static String validatePublicSymbol(String name) {
-    if (name.isEmpty || publicSymbolPattern.hasMatch(name)) return name;
-    if (name.startsWith('_')) {
-      // There may be other private parts in a qualified name than the first
-      // one, but this is a common case that deserves a specific error
-      // message.
-      throw new ArgumentError('"$name" is a private identifier');
-    }
-    throw new ArgumentError('"$name" is not a valid (qualified) symbol name');
-  }
-
-  /**
-   * Checks whether name is a valid symbol name.
-   *
-   * This test allows both private and non-private symbols.
-   */
-  static bool isValidSymbol(String name) {
-    return (name.isEmpty || symbolPattern.hasMatch(name));
-  }
-}