Change the signature of JSONReader::Read() and related methods to be more

base/json_reader.h

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // A JSON parser.  Converts strings of JSON into a Value object (see
 // base/values.h).
 // http://www.ietf.org/rfc/rfc4627.txt?number=4627
 //
 // Known limitations/deviations from the RFC:
 // - Only knows how to parse ints within the range of a signed 32 bit int and
@@ skipping 67 matching lines @@
   // Error messages that can be returned.
   static const char* kBadRootElementType;
   static const char* kInvalidEscape;
   static const char* kSyntaxError;
   static const char* kTrailingComma;
   static const char* kTooMuchNesting;
   static const char* kUnexpectedDataAfterRoot;
   static const char* kUnsupportedEncoding;
   static const char* kUnquotedDictionaryKey;
 
-  // Reads and parses |json| and populates |root|. If |json| is not a properly
-  // formed JSON string, returns false, leaves root unaltered and sets
-  // error_message if it was non-null. If allow_trailing_comma is true, we will
-  // ignore trailing commas in objects and arrays even though this goes against
-  // the RFC.
-  static bool Read(const std::string& json,
-                   Value** root,
-                   bool allow_trailing_comma);
+  // Reads and parses |json|, returning a Value. The caller owns the returned
+  // instance. If |json| is not a properly formed JSON string, returns NULL.
+  // If allow_trailing_comma is true, we will ignore trailing commas in objects
+  // and arrays even though this goes against the RFC.
+  static Value* Read(const std::string& json,
+                     bool allow_trailing_comma);
 
   // Reads and parses |json| like Read(). |error_message_out| is optional. If
-  // specified and false is returned, error_message_out will be populated with
+  // specified and NULL is returned, error_message_out will be populated with
   // a string describing the error. Otherwise, error_message_out is unmodified.
-  static bool ReadAndReturnError(const std::string& json,
-                                 Value** root,
-                                 bool allow_trailing_comma,
-                                 std::string *error_message_out);
+  static Value* ReadAndReturnError(const std::string& json,
+                                   bool allow_trailing_comma,
+                                   std::string *error_message_out);
 
  private:
   static std::string FormatErrorMessage(int line, int column,
                                         const char* description);
 
   JSONReader();
   DISALLOW_EVIL_CONSTRUCTORS(JSONReader);
 
   FRIEND_TEST(JSONReaderTest, Reading);
   FRIEND_TEST(JSONReaderTest, ErrorMessages);
 
   // Returns the error message if the last call to JsonToValue() failed. If the
   // last call did not fail, returns a valid empty string.
   std::string error_message() { return error_message_; }
 
   // Pass through method from JSONReader::Read.  We have this so unittests can
   // disable the root check.
-  bool JsonToValue(const std::string& json, Value** root, bool check_root,
-                   bool allow_trailing_comma);
+  Value* JsonToValue(const std::string& json, bool check_root,
+                     bool allow_trailing_comma);
 
-  // Recursively build Value.  Returns false if we don't have a valid JSON
+  // Recursively build Value.  Returns NULL if we don't have a valid JSON
   // string.  If |is_root| is true, we verify that the root element is either
   // an object or an array.
-  bool BuildValue(Value** root, bool is_root);
+  Value* BuildValue(bool is_root);
 
   // Parses a sequence of characters into a Token::NUMBER. If the sequence of
   // characters is not a valid number, returns a Token::INVALID_TOKEN. Note
   // that DecodeNumber is used to actually convert from a string to an
   // int/double.
   Token ParseNumberToken();
 
   // Try and convert the substring that token holds into an int or a double. If
-  // we can (ie., no overflow), return true and create the appropriate value
-  // for |node|.  Return false if we can't do the conversion.
-  bool DecodeNumber(const Token& token, Value** node);
+  // we can (ie., no overflow), return the value, else return NULL.
+  Value* DecodeNumber(const Token& token);
 
   // Parses a sequence of characters into a Token::STRING. If the sequence of
   // characters is not a valid string, returns a Token::INVALID_TOKEN. Note
   // that DecodeString is used to actually decode the escaped string into an
   // actual wstring.
   Token ParseStringToken();
 
   // Convert the substring into a value string.  This should always succeed
   // (otherwise ParseStringToken would have failed), but returns a success bool
   // just in case.
-  bool DecodeString(const Token& token, Value** node);
+  Value* DecodeString(const Token& token);
 
   // Grabs the next token in the JSON stream.  This does not increment the
   // stream so it can be used to look ahead at the next token.
   Token ParseToken();
 
   // Increments json_pos_ past leading whitespace and comments.
   void EatWhitespaceAndComments();
 
   // If json_pos_ is at the start of a comment, eat it, otherwise, returns
   // false.
@@ skipping 16 matching lines @@
   int stack_depth_;
 
   // A parser flag that allows trailing commas in objects and arrays.
   bool allow_trailing_comma_;
 
   // Contains the error message for the last call to JsonToValue(), if any.
   std::string error_message_;
 };
 
 #endif  // BASE_JSON_READER_H_