Remove dart:json

sdk/lib/json/json.dart

Index: sdk/lib/json/json.dart
diff --git a/sdk/lib/json/json.dart b/sdk/lib/json/json.dart
deleted file mode 100644
index ba9b7ac89cfb2f4d5b92596c3c066641eb0c4e0f..0000000000000000000000000000000000000000
--- a/sdk/lib/json/json.dart
+++ /dev/null
@@ -1,813 +0,0 @@
-// 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.
-
-/**
- * Utilities for encoding and decoding JSON (JavaScript Object Notation) data.
- */
-
-@deprecated
-library dart.json;
-
-import "dart:convert";
-import "dart:_collection-dev" show deprecated;
-import "dart:collection" show HashSet;
-export "dart:convert" show JsonUnsupportedObjectError, JsonCyclicError;
-
-// JSON parsing and serialization.
-
-/**
- * *DEPRECATED* Use `dart:convert JSON.decode` instead.
- *
- * Parses [json] and build the corresponding parsed JSON value.
- *
- * Parsed JSON values are of the types [num], [String], [bool], [Null],
- * [List]s of parsed JSON values or [Map]s from [String] to parsed
- * JSON values.
- *
- * The optional [reviver] function, if provided, is called once for each
- * object or list property parsed. The arguments are the property name
- * ([String]) or list index ([int]), and the value is the parsed value.
- * The return value of the reviver will be used as the value of that property
- * instead the parsed value.
- *
- * Throws [FormatException] if the input is not valid JSON text.
- */
-@deprecated
-parse(String json, [reviver(var key, var value)]) {
-  if (reviver != null) {
-    var original = reviver;
-    reviver = (key, value) => original(key == null ? "" : key, value);
-  }
-  return JSON.decode(json, reviver: reviver);
-}
-
-/**
- * *DEPRECATED* Use `dart:convert JSON.encode` instead.
- *
- * Serializes [object] into a JSON string.
- *
- * Directly serializable values are [num], [String], [bool], and [Null], as well
- * as some [List] and [Map] values.
- * For [List], the elements must all be serializable.
- * For [Map], the keys must be [String] and the values must be serializable.
- *
- * If a value is any other type is attempted serialized, the [toEncodable]
- * method is called with the object as argument, and the result, which must be a
- * directly serializable value, is serialized instead of the original value.
- * If [toEncodable] is omitted, the default is to call `object.toJson()` on the
- * object.
- *
- * If the conversion throws, or returns a value that is not directly
- * serializable, a [JsonUnsupportedObjectError] exception is thrown.
- * If the call throws (including the case where there
- * is no nullary "toJson" method), the error is caught and stored in the
- * [JsonUnsupportedObjectError]'s [:cause:] field.
- *
- * If a [List] or [Map] contains a reference to itself, directly or through
- * other lists or maps, it cannot be serialized and a [JsonCyclicError] is
- * thrown.
- *
- * The objects being serialized should not change during serialization.
- * If an object is serialized more than once, [stringify] is allowed to cache
- * the JSON text for it. I.e., if an object changes after it is first
- * serialized, the new values may or may not be reflected in the result.
- */
-@deprecated
-String stringify(Object object, [toEncodable(object)]) {
-  if (toEncodable == null) toEncodable = _defaultToEncodable;
-  return _JsonStringifier.stringify(object, toEncodable);
-}
-
-/**
- * *DEPRECATED* Use `package:json/json.dart` or `dart:convert` instead.
- *
- * Serializes [object] into [output] stream.
- *
- * Performs the same operations as [stringify] but outputs the resulting
- * string to an existing [StringSink] instead of creating a new [String].
- *
- * If serialization fails by throwing, some data might have been added to
- * [output], but it won't contain valid JSON text.
- */
-@deprecated
-void printOn(Object object, StringSink output, [ toEncodable(object) ]) {
-  if (toEncodable == null) toEncodable = _defaultToEncodable;
-  return _JsonStringifier.printOn(object, output, toEncodable);
-}
-
-//// Implementation ///////////////////////////////////////////////////////////
-
-// Simple API for JSON parsing.
-
-/// *DEPRECATED* Use `package:json/json.dart` instead.
-@deprecated
-abstract class JsonListener {
-  void handleString(String value) {}
-  void handleNumber(num value) {}
-  void handleBool(bool value) {}
-  void handleNull() {}
-  void beginObject() {}
-  void propertyName() {}
-  void propertyValue() {}
-  void endObject() {}
-  void beginArray() {}
-  void arrayElement() {}
-  void endArray() {}
-  /** Called on failure to parse [source]. */
-  void fail(String source, int position, String message) {}
-}
-
-/**
- * *DEPRECATED* Use `package:json/json.dart` instead.
- *
- * A [JsonListener] that builds data objects from the parser events.
- *
- * This is a simple stack-based object builder. It keeps the most recently
- * seen value in a variable, and uses it depending on the following event.
- */
-@deprecated
-class BuildJsonListener extends JsonListener {
-  /**
-   * Stack used to handle nested containers.
-   *
-   * The current container is pushed on the stack when a new one is
-   * started. If the container is a [Map], there is also a current [key]
-   * which is also stored on the stack.
-   */
-  List stack = [];
-  /** The current [Map] or [List] being built. */
-  var currentContainer;
-  /** The most recently read property key. */
-  String key;
-  /** The most recently read value. */
-  var value;
-
-  /** Pushes the currently active container (and key, if a [Map]). */
-  void pushContainer() {
-    if (currentContainer is Map) stack.add(key);
-    stack.add(currentContainer);
-  }
-
-  /** Pops the top container from the [stack], including a key if applicable. */
-  void popContainer() {
-    value = currentContainer;
-    currentContainer = stack.removeLast();
-    if (currentContainer is Map) key = stack.removeLast();
-  }
-
-  void handleString(String value) { this.value = value; }
-  void handleNumber(num value) { this.value = value; }
-  void handleBool(bool value) { this.value = value; }
-  void handleNull() { this.value = null; }
-
-  void beginObject() {
-    pushContainer();
-    currentContainer = {};
-  }
-
-  void propertyName() {
-    key = value;
-    value = null;
-  }
-
-  void propertyValue() {
-    Map map = currentContainer;
-    map[key] = value;
-    key = value = null;
-  }
-
-  void endObject() {
-    popContainer();
-  }
-
-  void beginArray() {
-    pushContainer();
-    currentContainer = [];
-  }
-
-  void arrayElement() {
-    List list = currentContainer;
-    currentContainer.add(value);
-    value = null;
-  }
-
-  void endArray() {
-    popContainer();
-  }
-
-  /** Read out the final result of parsing a JSON string. */
-  get result {
-    assert(currentContainer == null);
-    return value;
-  }
-}
-
-typedef _Reviver(var key, var value);
-
-/// *DEPRECATED* Use `package:json/json.dart` instead.
-@deprecated
-class ReviverJsonListener extends BuildJsonListener {
-  final _Reviver reviver;
-  ReviverJsonListener(reviver(key, value)) : this.reviver = reviver;
-
-  void arrayElement() {
-    List list = currentContainer;
-    value = reviver(list.length, value);
-    super.arrayElement();
-  }
-
-  void propertyValue() {
-    value = reviver(key, value);
-    super.propertyValue();
-  }
-
-  get result {
-    return reviver("", value);
-  }
-}
-
-/// *DEPRECATED* Use `package:json/json.dart` instead.
-@deprecated
-class JsonParser {
-  // A simple non-recursive state-based parser for JSON.
-  //
-  // Literal values accepted in states ARRAY_EMPTY, ARRAY_COMMA, OBJECT_COLON
-  // and strings also in OBJECT_EMPTY, OBJECT_COMMA.
-  //               VALUE  STRING  :  ,  }  ]        Transitions to
-  // EMPTY            X      X                   -> END
-  // ARRAY_EMPTY      X      X             @     -> ARRAY_VALUE / pop
-  // ARRAY_VALUE                     @     @     -> ARRAY_COMMA / pop
-  // ARRAY_COMMA      X      X                   -> ARRAY_VALUE
-  // OBJECT_EMPTY            X          @        -> OBJECT_KEY / pop
-  // OBJECT_KEY                   @              -> OBJECT_COLON
-  // OBJECT_COLON     X      X                   -> OBJECT_VALUE
-  // OBJECT_VALUE                    @  @        -> OBJECT_COMMA / pop
-  // OBJECT_COMMA            X                   -> OBJECT_KEY
-  // END
-  // Starting a new array or object will push the current state. The "pop"
-  // above means restoring this state and then marking it as an ended value.
-  // X means generic handling, @ means special handling for just that
-  // state - that is, values are handled generically, only punctuation
-  // cares about the current state.
-  // Values for states are chosen so bits 0 and 1 tell whether
-  // a string/value is allowed, and setting bits 0 through 2 after a value
-  // gets to the next state (not empty, doesn't allow a value).
-
-  // State building-block constants.
-  static const int INSIDE_ARRAY = 1;
-  static const int INSIDE_OBJECT = 2;
-  static const int AFTER_COLON = 3;  // Always inside object.
-
-  static const int ALLOW_STRING_MASK = 8;  // Allowed if zero.
-  static const int ALLOW_VALUE_MASK = 4;  // Allowed if zero.
-  static const int ALLOW_VALUE = 0;
-  static const int STRING_ONLY = 4;
-  static const int NO_VALUES = 12;
-
-  // Objects and arrays are "empty" until their first property/element.
-  static const int EMPTY = 0;
-  static const int NON_EMPTY = 16;
-  static const int EMPTY_MASK = 16;  // Empty if zero.
-
-
-  static const int VALUE_READ_BITS = NO_VALUES | NON_EMPTY;
-
-  // Actual states.
-  static const int STATE_INITIAL      = EMPTY | ALLOW_VALUE;
-  static const int STATE_END          = NON_EMPTY | NO_VALUES;
-
-  static const int STATE_ARRAY_EMPTY  = INSIDE_ARRAY | EMPTY | ALLOW_VALUE;
-  static const int STATE_ARRAY_VALUE  = INSIDE_ARRAY | NON_EMPTY | NO_VALUES;
-  static const int STATE_ARRAY_COMMA  = INSIDE_ARRAY | NON_EMPTY | ALLOW_VALUE;
-
-  static const int STATE_OBJECT_EMPTY = INSIDE_OBJECT | EMPTY | STRING_ONLY;
-  static const int STATE_OBJECT_KEY   = INSIDE_OBJECT | NON_EMPTY | NO_VALUES;
-  static const int STATE_OBJECT_COLON = AFTER_COLON | NON_EMPTY | ALLOW_VALUE;
-  static const int STATE_OBJECT_VALUE = AFTER_COLON | NON_EMPTY | NO_VALUES;
-  static const int STATE_OBJECT_COMMA = INSIDE_OBJECT | NON_EMPTY | STRING_ONLY;
-
-  // Character code constants.
-  static const int BACKSPACE       = 0x08;
-  static const int TAB             = 0x09;
-  static const int NEWLINE         = 0x0a;
-  static const int CARRIAGE_RETURN = 0x0d;
-  static const int FORM_FEED       = 0x0c;
-  static const int SPACE           = 0x20;
-  static const int QUOTE           = 0x22;
-  static const int PLUS            = 0x2b;
-  static const int COMMA           = 0x2c;
-  static const int MINUS           = 0x2d;
-  static const int DECIMALPOINT    = 0x2e;
-  static const int SLASH           = 0x2f;
-  static const int CHAR_0          = 0x30;
-  static const int CHAR_9          = 0x39;
-  static const int COLON           = 0x3a;
-  static const int CHAR_E          = 0x45;
-  static const int LBRACKET        = 0x5b;
-  static const int BACKSLASH       = 0x5c;
-  static const int RBRACKET        = 0x5d;
-  static const int CHAR_a          = 0x61;
-  static const int CHAR_b          = 0x62;
-  static const int CHAR_e          = 0x65;
-  static const int CHAR_f          = 0x66;
-  static const int CHAR_l          = 0x6c;
-  static const int CHAR_n          = 0x6e;
-  static const int CHAR_r          = 0x72;
-  static const int CHAR_s          = 0x73;
-  static const int CHAR_t          = 0x74;
-  static const int CHAR_u          = 0x75;
-  static const int LBRACE          = 0x7b;
-  static const int RBRACE          = 0x7d;
-
-  final String source;
-  final JsonListener listener;
-  JsonParser(this.source, this.listener);
-
-  /** Parses [source], or throws if it fails. */
-  void parse() {
-    final List<int> states = <int>[];
-    int state = STATE_INITIAL;
-    int position = 0;
-    int length = source.length;
-    while (position < length) {
-      int char = source.codeUnitAt(position);
-      switch (char) {
-        case SPACE:
-        case CARRIAGE_RETURN:
-        case NEWLINE:
-        case TAB:
-          position++;
-          break;
-        case QUOTE:
-          if ((state & ALLOW_STRING_MASK) != 0) fail(position);
-          position = parseString(position + 1);
-          state |= VALUE_READ_BITS;
-          break;
-        case LBRACKET:
-          if ((state & ALLOW_VALUE_MASK) != 0) fail(position);
-          listener.beginArray();
-          states.add(state);
-          state = STATE_ARRAY_EMPTY;
-          position++;
-          break;
-        case LBRACE:
-          if ((state & ALLOW_VALUE_MASK) != 0) fail(position);
-          listener.beginObject();
-          states.add(state);
-          state = STATE_OBJECT_EMPTY;
-          position++;
-          break;
-        case CHAR_n:
-          if ((state & ALLOW_VALUE_MASK) != 0) fail(position);
-          position = parseNull(position);
-          state |= VALUE_READ_BITS;
-          break;
-        case CHAR_f:
-          if ((state & ALLOW_VALUE_MASK) != 0) fail(position);
-          position = parseFalse(position);
-          state |= VALUE_READ_BITS;
-          break;
-        case CHAR_t:
-          if ((state & ALLOW_VALUE_MASK) != 0) fail(position);
-          position = parseTrue(position);
-          state |= VALUE_READ_BITS;
-          break;
-        case COLON:
-          if (state != STATE_OBJECT_KEY) fail(position);
-          listener.propertyName();
-          state = STATE_OBJECT_COLON;
-          position++;
-          break;
-        case COMMA:
-          if (state == STATE_OBJECT_VALUE) {
-            listener.propertyValue();
-            state = STATE_OBJECT_COMMA;
-            position++;
-          } else if (state == STATE_ARRAY_VALUE) {
-            listener.arrayElement();
-            state = STATE_ARRAY_COMMA;
-            position++;
-          } else {
-            fail(position);
-          }
-          break;
-        case RBRACKET:
-          if (state == STATE_ARRAY_EMPTY) {
-            listener.endArray();
-          } else if (state == STATE_ARRAY_VALUE) {
-            listener.arrayElement();
-            listener.endArray();
-          } else {
-            fail(position);
-          }
-          state = states.removeLast() | VALUE_READ_BITS;
-          position++;
-          break;
-        case RBRACE:
-          if (state == STATE_OBJECT_EMPTY) {
-            listener.endObject();
-          } else if (state == STATE_OBJECT_VALUE) {
-            listener.propertyValue();
-            listener.endObject();
-          } else {
-            fail(position);
-          }
-          state = states.removeLast() | VALUE_READ_BITS;
-          position++;
-          break;
-        default:
-          if ((state & ALLOW_VALUE_MASK) != 0) fail(position);
-          position = parseNumber(char, position);
-          state |= VALUE_READ_BITS;
-          break;
-      }
-    }
-    if (state != STATE_END) fail(position);
-  }
-
-  /**
-   * Parses a "true" literal starting at [position].
-   *
-   * [:source[position]:] must be "t".
-   */
-  int parseTrue(int position) {
-    assert(source.codeUnitAt(position) == CHAR_t);
-    if (source.length < position + 4) fail(position, "Unexpected identifier");
-    if (source.codeUnitAt(position + 1) != CHAR_r ||
-        source.codeUnitAt(position + 2) != CHAR_u ||
-        source.codeUnitAt(position + 3) != CHAR_e) {
-      fail(position);
-    }
-    listener.handleBool(true);
-    return position + 4;
-  }
-
-  /**
-   * Parses a "false" literal starting at [position].
-   *
-   * [:source[position]:] must be "f".
-   */
-  int parseFalse(int position) {
-    assert(source.codeUnitAt(position) == CHAR_f);
-    if (source.length < position + 5) fail(position, "Unexpected identifier");
-    if (source.codeUnitAt(position + 1) != CHAR_a ||
-        source.codeUnitAt(position + 2) != CHAR_l ||
-        source.codeUnitAt(position + 3) != CHAR_s ||
-        source.codeUnitAt(position + 4) != CHAR_e) {
-      fail(position);
-    }
-    listener.handleBool(false);
-    return position + 5;
-  }
-
-  /** Parses a "null" literal starting at [position].
-   *
-   * [:source[position]:] must be "n".
-   */
-  int parseNull(int position) {
-    assert(source.codeUnitAt(position) == CHAR_n);
-    if (source.length < position + 4) fail(position, "Unexpected identifier");
-    if (source.codeUnitAt(position + 1) != CHAR_u ||
-        source.codeUnitAt(position + 2) != CHAR_l ||
-        source.codeUnitAt(position + 3) != CHAR_l) {
-      fail(position);
-    }
-    listener.handleNull();
-    return position + 4;
-  }
-
-  int parseString(int position) {
-    // Format: '"'([^\x00-\x1f\\\"]|'\\'[bfnrt/\\"])*'"'
-    // Initial position is right after first '"'.
-    int start = position;
-    int char;
-    do {
-      if (position == source.length) {
-        fail(start - 1, "Unterminated string");
-      }
-      char = source.codeUnitAt(position);
-      if (char == QUOTE) {
-        String result = source.substring(start, position);
-        listener.handleString(result);
-        return position + 1;
-      }
-      if (char < SPACE) {
-        fail(position, "Control character in string");
-      }
-      position++;
-    } while (char != BACKSLASH);
-    // Backslash escape detected. Collect character codes for rest of string.
-    int firstEscape = position - 1;
-    List<int> chars = <int>[];
-    while (true) {
-      if (position == source.length) {
-        fail(start - 1, "Unterminated string");
-      }
-      char = source.codeUnitAt(position);
-      switch (char) {
-        case CHAR_b: char = BACKSPACE; break;
-        case CHAR_f: char = FORM_FEED; break;
-        case CHAR_n: char = NEWLINE; break;
-        case CHAR_r: char = CARRIAGE_RETURN; break;
-        case CHAR_t: char = TAB; break;
-        case SLASH:
-        case BACKSLASH:
-        case QUOTE:
-          break;
-        case CHAR_u:
-          int hexStart = position - 1;
-          int value = 0;
-          for (int i = 0; i < 4; i++) {
-            position++;
-            if (position == source.length) {
-              fail(start - 1, "Unterminated string");
-            }
-            char = source.codeUnitAt(position);
-            char -= 0x30;
-            if (char < 0) fail(hexStart, "Invalid unicode escape");
-            if (char < 10) {
-              value = value * 16 + char;
-            } else {
-              char = (char | 0x20) - 0x31;
-              if (char < 0 || char > 5) {
-                fail(hexStart, "Invalid unicode escape");
-              }
-              value = value * 16 + char + 10;
-            }
-          }
-          char = value;
-          break;
-        default:
-          if (char < SPACE) fail(position, "Control character in string");
-          fail(position, "Unrecognized string escape");
-      }
-      do {
-        chars.add(char);
-        position++;
-        if (position == source.length) fail(start - 1, "Unterminated string");
-        char = source.codeUnitAt(position);
-        if (char == QUOTE) {
-          String result = new String.fromCharCodes(chars);
-          if (start < firstEscape) {
-            result = "${source.substring(start, firstEscape)}$result";
-          }
-          listener.handleString(result);
-          return position + 1;
-        }
-        if (char < SPACE) {
-          fail(position, "Control character in string");
-        }
-      } while (char != BACKSLASH);
-      position++;
-    }
-  }
-
-  int _handleLiteral(start, position, isDouble) {
-    String literal = source.substring(start, position);
-    // This correctly creates -0 for doubles.
-    num value = (isDouble ? double.parse(literal) : int.parse(literal));
-    listener.handleNumber(value);
-    return position;
-  }
-
-  int parseNumber(int char, int position) {
-    // Format:
-    //  '-'?('0'|[1-9][0-9]*)('.'[0-9]+)?([eE][+-]?[0-9]+)?
-    int start = position;
-    int length = source.length;
-    bool isDouble = false;
-    if (char == MINUS) {
-      position++;
-      if (position == length) fail(position, "Missing expected digit");
-      char = source.codeUnitAt(position);
-    }
-    if (char < CHAR_0 || char > CHAR_9) {
-      fail(position, "Missing expected digit");
-    }
-    if (char == CHAR_0) {
-      position++;
-      if (position == length) return _handleLiteral(start, position, false);
-      char = source.codeUnitAt(position);
-      if (CHAR_0 <= char && char <= CHAR_9) {
-        fail(position);
-      }
-    } else {
-      do {
-        position++;
-        if (position == length) return _handleLiteral(start, position, false);
-        char = source.codeUnitAt(position);
-      } while (CHAR_0 <= char && char <= CHAR_9);
-    }
-    if (char == DECIMALPOINT) {
-      isDouble = true;
-      position++;
-      if (position == length) fail(position, "Missing expected digit");
-      char = source.codeUnitAt(position);
-      if (char < CHAR_0 || char > CHAR_9) fail(position);
-      do {
-        position++;
-        if (position == length) return _handleLiteral(start, position, true);
-        char = source.codeUnitAt(position);
-      } while (CHAR_0 <= char && char <= CHAR_9);
-    }
-    if (char == CHAR_e || char == CHAR_E) {
-      isDouble = true;
-      position++;
-      if (position == length) fail(position, "Missing expected digit");
-      char = source.codeUnitAt(position);
-      if (char == PLUS || char == MINUS) {
-        position++;
-        if (position == length) fail(position, "Missing expected digit");
-        char = source.codeUnitAt(position);
-      }
-      if (char < CHAR_0 || char > CHAR_9) {
-        fail(position, "Missing expected digit");
-      }
-      do {
-        position++;
-        if (position == length) return _handleLiteral(start, position, true);
-        char = source.codeUnitAt(position);
-      } while (CHAR_0 <= char && char <= CHAR_9);
-    }
-    return _handleLiteral(start, position, isDouble);
-  }
-
-  void fail(int position, [String message]) {
-    if (message == null) message = "Unexpected character";
-    listener.fail(source, position, message);
-    // If the listener didn't throw, do it here.
-    String slice;
-    int sliceEnd = position + 20;
-    if (sliceEnd > source.length) {
-      slice = "'${source.substring(position)}'";
-    } else {
-      slice = "'${source.substring(position, sliceEnd)}...'";
-    }
-    throw new FormatException("Unexpected character at $position: $slice");
-  }
-}
-
-Object _defaultToEncodable(object) => object.toJson();
-
-class _JsonStringifier {
-  final Function toEncodable;
-  final StringSink sink;
-  final Set<Object> seen;
-
-  _JsonStringifier(this.sink, this.toEncodable)
-      : this.seen = new HashSet.identity();
-
-  static String stringify(final object, toEncodable(object)) {
-    StringBuffer output = new StringBuffer();
-    _JsonStringifier stringifier = new _JsonStringifier(output, toEncodable);
-    stringifier.stringifyValue(object);
-    return output.toString();
-  }
-
-  static void printOn(final object, StringSink output, toEncodable(object)) {
-    _JsonStringifier stringifier = new _JsonStringifier(output, toEncodable);
-    stringifier.stringifyValue(object);
-  }
-
-  static String numberToString(num x) {
-    return x.toString();
-  }
-
-  // ('0' + x) or ('a' + x - 10)
-  static int hexDigit(int x) => x < 10 ? 48 + x : 87 + x;
-
-  static void escape(StringSink sb, String s) {
-    final int length = s.length;
-    bool needsEscape = false;
-    final charCodes = new List<int>();
-    for (int i = 0; i < length; i++) {
-      int charCode = s.codeUnitAt(i);
-      if (charCode < 32) {
-        needsEscape = true;
-        charCodes.add(JsonParser.BACKSLASH);
-        switch (charCode) {
-        case JsonParser.BACKSPACE:
-          charCodes.add(JsonParser.CHAR_b);
-          break;
-        case JsonParser.TAB:
-          charCodes.add(JsonParser.CHAR_t);
-          break;
-        case JsonParser.NEWLINE:
-          charCodes.add(JsonParser.CHAR_n);
-          break;
-        case JsonParser.FORM_FEED:
-          charCodes.add(JsonParser.CHAR_f);
-          break;
-        case JsonParser.CARRIAGE_RETURN:
-          charCodes.add(JsonParser.CHAR_r);
-          break;
-        default:
-          charCodes.add(JsonParser.CHAR_u);
-          charCodes.add(hexDigit((charCode >> 12) & 0xf));
-          charCodes.add(hexDigit((charCode >> 8) & 0xf));
-          charCodes.add(hexDigit((charCode >> 4) & 0xf));
-          charCodes.add(hexDigit(charCode & 0xf));
-          break;
-        }
-      } else if (charCode == JsonParser.QUOTE ||
-          charCode == JsonParser.BACKSLASH) {
-        needsEscape = true;
-        charCodes.add(JsonParser.BACKSLASH);
-        charCodes.add(charCode);
-      } else {
-        charCodes.add(charCode);
-      }
-    }
-    sb.write(needsEscape ? new String.fromCharCodes(charCodes) : s);
-  }
-
-  void checkCycle(final object) {
-    if (seen.contains(object)) {
-      throw new JsonCyclicError(object);
-    }
-    seen.add(object);
-  }
-
-  void stringifyValue(final object) {
-    // Tries stringifying object directly. If it's not a simple value, List or
-    // Map, call toJson() to get a custom representation and try serializing
-    // that.
-    if (!stringifyJsonValue(object)) {
-      checkCycle(object);
-      try {
-        var customJson = toEncodable(object);
-        if (!stringifyJsonValue(customJson)) {
-          throw new JsonUnsupportedObjectError(object);
-        }
-        seen.remove(object);
-      } catch (e) {
-        throw new JsonUnsupportedObjectError(object, cause: e);
-      }
-    }
-  }
-
-  /**
-   * Serializes a [num], [String], [bool], [Null], [List] or [Map] value.
-   *
-   * Returns true if the value is one of these types, and false if not.
-   * If a value is both a [List] and a [Map], it's serialized as a [List].
-   */
-  bool stringifyJsonValue(final object) {
-    if (object is num) {
-      // TODO: use writeOn.
-      sink.write(numberToString(object));
-      return true;
-    } else if (identical(object, true)) {
-      sink.write('true');
-      return true;
-    } else if (identical(object, false)) {
-      sink.write('false');
-       return true;
-    } else if (object == null) {
-      sink.write('null');
-      return true;
-    } else if (object is String) {
-      sink.write('"');
-      escape(sink, object);
-      sink.write('"');
-      return true;
-    } else if (object is List) {
-      checkCycle(object);
-      List a = object;
-      sink.write('[');
-      if (a.length > 0) {
-        stringifyValue(a[0]);
-        // TODO: switch to Iterables.
-        for (int i = 1; i < a.length; i++) {
-          sink.write(',');
-          stringifyValue(a[i]);
-        }
-      }
-      sink.write(']');
-      seen.remove(object);
-      return true;
-    } else if (object is Map) {
-      checkCycle(object);
-      Map<String, Object> m = object;
-      sink.write('{');
-      bool first = true;
-      m.forEach((String key, Object value) {
-        if (!first) {
-          sink.write(',"');
-        } else {
-          sink.write('"');
-        }
-        escape(sink, key);
-        sink.write('":');
-        stringifyValue(value);
-        first = false;
-      });
-      sink.write('}');
-      seen.remove(object);
-      return true;
-    } else {
-      return false;
-    }
-  }
-}