Update charted to 0.4.8 and roll

packages/petitparser/lib/src/json/parser.dart

-part of petitparser.json;
-
-/// JSON parser.
-class JsonParser extends GrammarParser {
-  JsonParser() : super(const JsonParserDefinition());
-}
-
-/// JSON parser definition.
-class JsonParserDefinition extends JsonGrammarDefinition {
-  const JsonParserDefinition();
-
-  array() => super.array().map((each) => each[1] != null ? each[1] : new List());
-  object() => super.object().map((each) {
-    var result = new LinkedHashMap();
-    if (each[1] != null) {
-      for (var element in each[1]) {
-        result[element[0]] = element[2];
-      }
-    }
-    return result;
-  });
-
-  trueToken() => super.trueToken().map((each) => true);
-  falseToken() => super.falseToken().map((each) => false);
-  nullToken() => super.nullToken().map((each) => null);
-  stringToken() => ref(stringPrimitive).trim();
-  numberToken() => super.numberToken().map((each) {
-    var floating = double.parse(each);
-    var integral = floating.toInt();
-    if (floating == integral && each.indexOf('.') == -1) {
-      return integral;
-    } else {
-      return floating;
-    }
-  });
-
-  stringPrimitive() => super.stringPrimitive().map((each) => each[1].join());
-  characterEscape() => super.characterEscape().map((each) => jsonEscapeChars[each[1]]);
-  characterUnicode() => super.characterUnicode().map((each) {
-    var charCode = int.parse(each[1].join(), radix: 16);
-    return new String.fromCharCode(charCode);
-  });
-}