Move frog/leg to lib/compiler/implementation.

frog/leg/scanner/string_scanner.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.
-
-/**
- * Scanner that reads from a String and creates tokens that points to
- * substrings.
- */
-class StringScanner extends ArrayBasedScanner<SourceString> {
-  final String string;
-
-  StringScanner(String this.string) : super();
-
-  int nextByte() => charAt(++byteOffset);
-
-  int peek() => charAt(byteOffset + 1);
-
-  int charAt(index)
-      => (string.length > index) ? string.charCodeAt(index) : $EOF;
-
-  SourceString asciiString(int start, int offset) {
-    return new SubstringWrapper(string, start, byteOffset + offset);
-  }
-
-  SourceString utf8String(int start, int offset) {
-    return new SubstringWrapper(string, start, byteOffset + offset + 1);
-  }
-
-  void appendByteStringToken(PrecedenceInfo info, SourceString value) {
-    // assert(kind != $a || keywords.get(value) == null);
-    tail.next = new StringToken.fromSource(info, value, tokenStart);
-    tail = tail.next;
-  }
-}
-
-class SubstringWrapper implements SourceString {
-  final String internalString;
-  final int begin;
-  final int end;
-
-  const SubstringWrapper(String this.internalString,
-                         int this.begin, int this.end);
-
-  int hashCode() => slowToString().hashCode();
-
-  bool operator ==(other) {
-    return other is SourceString && slowToString() == other.slowToString();
-  }
-
-  void printOn(StringBuffer sb) {
-    sb.add(internalString.substring(begin, end));
-  }
-
-  String slowToString() => internalString.substring(begin, end);
-
-  String toString() => "SubstringWrapper(${slowToString()})";
-
-  String get stringValue() => null;
-
-  Iterator<int> iterator() =>
-      new StringCodeIterator.substring(internalString, begin, end);
-
-  SourceString copyWithoutQuotes(int initial, int terminal) {
-    assert(0 <= initial);
-    assert(0 <= terminal);
-    assert(initial + terminal <= internalString.length);
-    return new SubstringWrapper(internalString,
-                                begin + initial, end - terminal);
-  }
-
-  bool isEmpty() => begin == end;
-
-  bool isPrivate() => !isEmpty() && internalString.charCodeAt(begin) === $_;
-}