Move dart2js from sdk/lib/_internal/compiler to pkg/compiler

sdk/lib/_internal/compiler/implementation/tree/dartstring.dart

-// Copyright (c) 2012, 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 tree;
-
-/**
- * The [DartString] type represents a Dart string value as a sequence of Unicode
- * Scalar Values.
- * After parsing, any valid [LiteralString] will contain a [DartString]
- * representing its content after removing quotes and resolving escapes in
- * its source.
- */
-abstract class DartString extends IterableBase<int> {
-  factory DartString.empty() => const LiteralDartString("");
-  // This is a convenience constructor. If you need a const literal DartString,
-  // use [const LiteralDartString(string)] directly.
-  factory DartString.literal(String string) => new LiteralDartString(string);
-  factory DartString.rawString(String source, int length) =>
-      new RawSourceDartString(source, length);
-  factory DartString.escapedString(String source, int length) =>
-      new EscapedSourceDartString(source, length);
-  factory DartString.concat(DartString first, DartString second) {
-    if (first.isEmpty) return second;
-    if (second.isEmpty) return first;
-    return new ConsDartString(first, second);
-  }
-  const DartString();
-
-  /**
-   * The length of this [DartString], which is the string length after
-   * escapes have been resolved.
-   */
-  int get length;
-  bool get isEmpty => length == 0;
-
-  Iterator<int> get iterator;
-
-  /**
-   * The string represented by this [DartString].
-   */
-  String slowToString();
-
-  bool operator ==(var other) {
-    if (other is !DartString) return false;
-    DartString otherString = other;
-    if (length != otherString.length) return false;
-    Iterator it1 = iterator;
-    Iterator it2 = otherString.iterator;
-    while (it1.moveNext()) {
-      if (!it2.moveNext()) return false;
-      if (it1.current != it2.current) return false;
-    }
-    return true;
-  }
-
-  int get hashCode => throw new UnsupportedError('DartString.hashCode');
-
-  /**
-   * A textual representation of this [DartString] with some debugging
-   * information.
-   */
-  String toString() => "DartString#${length}:${slowToString()}";
-}
-
-
-/**
- * A [DartString] where the content is represented by an actual [String].
- */
-class LiteralDartString extends DartString {
-  final String string;
-  const LiteralDartString(this.string);
-  int get length => string.length;
-  Iterator<int> get iterator => string.codeUnits.iterator;
-  String slowToString() => string;
-}
-
-/**
- * A [DartString] whereSource the content comes from a slice of the program
- * source.
- */
-abstract class SourceBasedDartString extends DartString {
-  /**
-   * The source string containing explicit escapes from which this [DartString]
-   * is built.
-   */
-  final String source;
-  final int length;
-  SourceBasedDartString(this.source, this.length);
-  Iterator<int> get iterator;
-}
-
-/**
- * Special case of a [SourceBasedDartString] where we know the source doesn't
- * contain any escapes.
- */
-class RawSourceDartString extends SourceBasedDartString {
-  RawSourceDartString(source, length) : super(source, length);
-  Iterator<int> get iterator => source.codeUnits.iterator;
-  String slowToString() => source;
-}
-
-/**
- * General case of a [SourceBasedDartString] where the source might contain
- * escapes.
- */
-class EscapedSourceDartString extends SourceBasedDartString {
-  String toStringCache;
-  EscapedSourceDartString(source, length) : super(source, length);
-  Iterator<int> get iterator {
-    if (toStringCache != null) return toStringCache.codeUnits.iterator;
-    return new StringEscapeIterator(source);
-  }
-  String slowToString() {
-    if (toStringCache != null) return toStringCache;
-    StringBuffer buffer = new StringBuffer();
-    StringEscapeIterator it = new StringEscapeIterator(source);
-    while (it.moveNext()) {
-      buffer.writeCharCode(it.current);
-    }
-    toStringCache = buffer.toString();
-    return toStringCache;
-  }
-}
-
-/**
- * The concatenation of two [DartString]s.
- */
-class ConsDartString extends DartString {
-  final DartString left;
-  final DartString right;
-  final int length;
-  String toStringCache;
-  ConsDartString(DartString left, DartString right)
-      : this.left = left,
-        this.right = right,
-        length = left.length + right.length;
-
-  Iterator<int> get iterator => new ConsDartStringIterator(this);
-
-  String slowToString() {
-    if (toStringCache != null) return toStringCache;
-    toStringCache = left.slowToString() + right.slowToString();
-    return toStringCache;
-  }
-  String get source => slowToString();
-}
-
-class ConsDartStringIterator implements Iterator<int> {
-  HasNextIterator<int> currentIterator;
-  DartString right;
-  bool hasNextLookAhead;
-  int _current = null;
-
-  ConsDartStringIterator(ConsDartString cons)
-      : currentIterator = new HasNextIterator<int>(cons.left.iterator),
-        right = cons.right {
-    hasNextLookAhead = currentIterator.hasNext;
-    if (!hasNextLookAhead) {
-      nextPart();
-    }
-  }
-
-  int get current => _current;
-
-  bool moveNext() {
-    if (!hasNextLookAhead) {
-      _current = null;
-      return false;
-    }
-    _current = currentIterator.next();
-    hasNextLookAhead = currentIterator.hasNext;
-    if (!hasNextLookAhead) {
-      nextPart();
-    }
-    return true;
-  }
-  void nextPart() {
-    if (right != null) {
-      currentIterator = new HasNextIterator<int>(right.iterator);
-      right = null;
-      hasNextLookAhead = currentIterator.hasNext;
-    }
-  }
-}
-
-/**
- *Iterator that returns the actual string contents of a string with escapes.
- */
-class StringEscapeIterator implements Iterator<int>{
-  final Iterator<int> source;
-  int _current = null;
-
-  StringEscapeIterator(String source) : this.source = source.codeUnits.iterator;
-
-  int get current => _current;
-
-  bool moveNext() {
-    if (!source.moveNext()) {
-      _current = null;
-      return false;
-    }
-    int code = source.current;
-    if (code != $BACKSLASH) {
-      _current = code;
-      return true;
-    }
-    source.moveNext();
-    code = source.current;
-    switch (code) {
-      case $n: _current = $LF; break;
-      case $r: _current = $CR; break;
-      case $t: _current = $TAB; break;
-      case $b: _current = $BS; break;
-      case $f: _current = $FF; break;
-      case $v: _current = $VTAB; break;
-      case $x:
-        source.moveNext();
-        int value = hexDigitValue(source.current);
-        source.moveNext();
-        value = value * 16 + hexDigitValue(source.current);
-        _current = value;
-        break;
-      case $u:
-        int value = 0;
-        source.moveNext();
-        code = source.current;
-        if (code == $OPEN_CURLY_BRACKET) {
-          source.moveNext();
-          while (source.current != $CLOSE_CURLY_BRACKET) {
-            value = value * 16 + hexDigitValue(source.current);
-            source.moveNext();
-          }
-          _current = value;
-          break;
-        }
-        // Four digit hex value.
-        value = hexDigitValue(code);
-        for (int i = 0; i < 3; i++) {
-          source.moveNext();
-          value = value * 16 + hexDigitValue(source.current);
-        }
-        _current = value;
-        break;
-      default:
-        _current = code;
-    }
-    return true;
-  }
-}
-