Move frog/leg to lib/compiler/implementation.

frog/leg/scanner/byte_strings.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.
-
-/**
- * An abstract string representation.
- */
-class ByteString implements SourceString {
-  final List<int> bytes;
-  final int offset;
-  final int length;
-  int _hashCode;
-
-  ByteString(List<int> this.bytes, int this.offset, int this.length);
-
-  abstract String get charset();
-
-  String slowToString() => new String.fromCharCodes(
-      new Utf8Decoder(bytes, offset, length).decodeRest());
-
-  String toString() => "ByteString(${slowToString()})";
-
-  bool operator ==(other) {
-    throw "should be overridden in subclass";
-  }
-
-  Iterator<int> iterator() => new Utf8Decoder(bytes, offset, length);
-
-  int hashCode() {
-    if (_hashCode === null) {
-      _hashCode = computeHashCode();
-    }
-    return _hashCode;
-  }
-
-  int computeHashCode() {
-    int code = 1;
-    int end = offset + length;
-    for (int i = offset; i < end; i++) {
-      code += 19 * code + bytes[i];
-    }
-    return code;
-  }
-
-  printOn(StringBuffer sb) {
-    sb.add(slowToString());
-  }
-
-  bool isEmpty() => length == 0;
-}
-
-/**
- * A string that consists purely of 7bit ASCII characters.
- */
-class AsciiString extends ByteString {
-  final String charset = "ASCII";
-
-  AsciiString(List<int> bytes, int offset, int length)
-    : super(bytes, offset, length);
-
-  static AsciiString of(List<int> bytes, int offset, int length) {
-    AsciiString string = new AsciiString(bytes, offset, length);
-    return string;
-  }
-
-  Iterator<int> iterator() => new AsciiStringIterator(bytes);
-
-  SourceString copyWithoutQuotes(int initial, int terminal) {
-    return new AsciiString(bytes, offset + initial,
-                           length - initial - terminal);
-  }
-
-
-  static AsciiString fromString(String string) {
-    List<int> bytes = string.charCodes();
-    return AsciiString.of(bytes, 0, bytes.length);
-  }
-}
-
-
-class AsciiStringIterator implements Iterator<int> {
-  final List<int> bytes;
-  int offset;
-  final int end;
-  AsciiStringIterator(List<int> bytes)
-      : this.bytes = bytes, offset = 0, end = bytes.length;
-  AsciiStringIterator.range(List<int> bytes, int from, int length)
-      : this.bytes = bytes, offset = from, end = from + length;
-  bool hasNext() => offset < end;
-  int next() => bytes[offset++];
-}
-
-
-/**
- * A string that consists of characters that can be encoded as UTF-8.
- */
-class Utf8String extends ByteString {
-  final String charset = "UTF8";
-
-  Utf8String(List<int> bytes, int offset, int length)
-    : super(bytes, offset, length);
-
-  static Utf8String of(List<int> bytes, int offset, int length) {
-    return new Utf8String(bytes, offset, length);
-  }
-
-  static Utf8String fromString(String string) {
-    throw "not implemented yet";
-  }
-
-  Iterator<int> iterator() => new Utf8Decoder(bytes, 0, length);
-
-  SourceString copyWithoutQuotes(int initial, int terminal) {
-    assert((){
-      // Only allow dropping ASCII characters, to guarantee that
-      // the resulting Utf8String is still valid.
-      for (int i = 0; i < initial; i++) {
-        if (bytes[offset + i] >= 0x80) return false;
-      }
-      for (int i = 0; i < terminal; i++) {
-        if (bytes[offset + length - terminal + i] >= 0x80) return false;
-      }
-      return true;
-    });
-    // TODO(lrn): Check that first and last bytes use the same type of quotes.
-    return new Utf8String(bytes, offset + initial,
-                          length - initial - terminal);
-  }
-}
-
-/**
- * A ByteString-valued token.
- */
-class ByteStringToken extends Token {
-  final ByteString value;
-
-  ByteStringToken(PrecedenceInfo info, ByteString this.value, int charOffset)
-    : super(info, charOffset);
-
-  String toString() => value.toString();
-}