dart:convert library.

sdk/lib/json/json.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.
 
 library dart.json;
 
 // JSON parsing and serialization.
 
 /**
  * Error thrown by JSON serialization if an object cannot be serialized.
@@ skipping 92 matching lines @@
  * serialized, the new values may or may not be reflected in the result.
  */
 String stringify(Object object) {
   return _JsonStringifier.stringify(object);
 }
 
 /**
  * Serializes [object] into [output] stream.
  *
  * Performs the same operations as [stringify] but outputs the resulting
- * string to an existing [StringBuffer] instead of creating a new [String].
+ * 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.
  */
-void printOn(Object object, StringBuffer output) {
+void printOn(Object object, StringSink output) {
   return _JsonStringifier.printOn(object, output);
 }
 
 //// Implementation ///////////////////////////////////////////////////////////
 
 // Simple API for JSON parsing.
 
 abstract class JsonListener {
   void handleString(String value) {}
   void handleNumber(num value) {}
@@ skipping 527 matching lines @@
       slice = "'${source.substring(position)}'";
     } else {
       slice = "'${source.substring(position, sliceEnd)}...'";
     }
     throw new FormatException("Unexpected character at $position: $slice");
   }
 }
 
 
 class _JsonStringifier {
-  StringBuffer sb;
+  StringSink sink;
   List<Object> seen;  // TODO: that should be identity set.
 
-  _JsonStringifier(this.sb) : seen = [];
+  _JsonStringifier(this.sink) : seen = [];
 
   static String stringify(final object) {
     StringBuffer output = new StringBuffer();
     _JsonStringifier stringifier = new _JsonStringifier(output);
     stringifier.stringifyValue(object);
     return output.toString();
   }
 
-  static void printOn(final object, StringBuffer output) {
+  static void printOn(final object, StringSink output) {
     _JsonStringifier stringifier = new _JsonStringifier(output);
     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(StringBuffer sb, String s) {
+  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:
@@ skipping 61 matching lines @@
 
   /**
    * 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.
-      sb.write(numberToString(object));
+      sink.write(numberToString(object));
       return true;
     } else if (identical(object, true)) {
-      sb.write('true');
+      sink.write('true');
       return true;
     } else if (identical(object, false)) {
-      sb.write('false');
+      sink.write('false');
        return true;
     } else if (object == null) {
-      sb.write('null');
+      sink.write('null');
       return true;
     } else if (object is String) {
-      sb.write('"');
-      escape(sb, object);
-      sb.write('"');
+      sink.write('"');
+      escape(sink, object);
+      sink.write('"');
       return true;
     } else if (object is List) {
       checkCycle(object);
       List a = object;
-      sb.write('[');
+      sink.write('[');
       if (a.length > 0) {
         stringifyValue(a[0]);
         // TODO: switch to Iterables.
         for (int i = 1; i < a.length; i++) {
-          sb.write(',');
+          sink.write(',');
           stringifyValue(a[i]);
         }
       }
-      sb.write(']');
+      sink.write(']');
       seen.removeLast();
       return true;
     } else if (object is Map) {
       checkCycle(object);
       Map<String, Object> m = object;
-      sb.write('{');
+      sink.write('{');
       bool first = true;
       m.forEach((String key, Object value) {
         if (!first) {
-          sb.write(',"');
+          sink.write(',"');
         } else {
-          sb.write('"');
+          sink.write('"');
         }
-        escape(sb, key);
-        sb.write('":');
+        escape(sink, key);
+        sink.write('":');
         stringifyValue(value);
         first = false;
       });
-      sb.write('}');
+      sink.write('}');
       seen.removeLast();
       return true;
     } else {
       return false;
     }
   }
 }