Add option for not adding '.0' to the end of doubles that have no fractional

base/json/json_writer.h

Index: base/json/json_writer.h
diff --git a/base/json/json_writer.h b/base/json/json_writer.h
index 88c7d58101bf5ca69b5c53a4c233564d828d97ac..9475e3329f75161f470bea5971ca0ec707138e6b 100644
--- a/base/json/json_writer.h
+++ b/base/json/json_writer.h
@@ -25,7 +25,20 @@ class BASE_EXPORT JSONWriter {
 
     // For values of binary type, the value (and key if within a dictionary)
     // will be omitted from the output.
-    OPTIONS_OMIT_BINARY_VALUES = 1 << 1
+    OPTIONS_OMIT_BINARY_VALUES = 1 << 1,
+
+    // An external consumer of your JSON may expect a 64-bit integer value.
+    // However, the |Value| classes only support 32-bit ints. One feasible
+    // way to mitigate this is to use a double to represent the integer.
+    // However, this class writes all doubles in such a way that causes many
+    // JSON readers to convert the number to a double instead of a 64-bit int.
+    // This may break the external consumer of the JSON if it expects a
+    // 64-bit int.
+    // This option instructs the writer to write doubles that have no fractional
+    // part as a normal integer (i.e., without using exponential notation
+    // or appending a '.0') as long as the value is within the range of a
+    // 64-bit int.
+    OPTIONS_ALLOW_DOUBLES_AS_INTEGERS = 1 << 2

[tony, 2012/03/06 17:57:25]

The name of this is confusing because JSON doesn't have a notion of double or
int.  Maybe something like OPTIONS_OMIT_DECIMAL_HINT?

[kkania, 2012/03/06 21:26:09]

That's a much better name, but the option also prevents exponential notation in
addition to no decimal points. How about OPTIONS_OMIT_DOUBLE_TYPE_PRESERVATION?

   };
 
   // Given a root node, generates a JSON string and puts it into |json|.
@@ -53,7 +66,8 @@ class BASE_EXPORT JSONWriter {
   // Called recursively to build the JSON string.  Whe completed, value is
   // json_string_ will contain the JSON.
   void BuildJSONString(const Value* const node, int depth, bool escape,
-                       bool ignore_binary_values);
+                       bool ignore_binary_values,
+                       bool allow_doubles_as_integers);
 
   // Appends a quoted, escaped, version of (UTF-8) str to json_string_.
   void AppendQuotedString(const std::string& str);