univalue: add support for real, fix percision and make it json_spirit compatible

- avoid breaking the API because of different number/percision handling

src/univalue/univalue.cpp

@@ -4,6 +4,7 @@
 
 #include <stdint.h>
 #include <ctype.h>
+#include <iomanip>
 #include <sstream>
 #include "univalue.h"
 
@@ -78,9 +79,11 @@ bool UniValue::setFloat(double val)
     string s;
     ostringstream oss;
 
-    oss << val;
+    oss << std::setprecision(16) << val;
 
-    return setNumStr(oss.str());
+    bool ret = setNumStr(oss.str());
+    typ = VREAL;
+    return ret;
 }
 
 bool UniValue::setStr(const string& val_)
@@ -203,6 +206,7 @@ const char *uvTypeName(UniValue::VType t)
     case UniValue::VARR: return "array";
     case UniValue::VSTR: return "string";
     case UniValue::VNUM: return "number";
+    case UniValue::VREAL: return "number";
     }
 
     // not reached

src/univalue/univalue.h

@@ -17,7 +17,7 @@
 
 class UniValue {
 public:
-    enum VType { VNULL, VOBJ, VARR, VSTR, VNUM, VBOOL, };
+    enum VType { VNULL, VOBJ, VARR, VSTR, VNUM, VREAL, VBOOL, };
 
     UniValue() { typ = VNULL; }
     UniValue(UniValue::VType initialType, const std::string& initialStr = "") {
@@ -76,6 +76,7 @@ public:
     bool isBool() const { return (typ == VBOOL); }
     bool isStr() const { return (typ == VSTR); }
     bool isNum() const { return (typ == VNUM); }
+    bool isReal() const { return (typ == VREAL); }
     bool isArray() const { return (typ == VARR); }
     bool isObject() const { return (typ == VOBJ); }
 

src/univalue/univalue_write.cpp

@@ -3,6 +3,8 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <ctype.h>
+#include <iomanip>
+#include <sstream>
 #include <stdio.h>
 #include "univalue.h"
 #include "univalue_escapes.h"
@@ -59,6 +61,13 @@ string UniValue::write(unsigned int prettyIndent,
     case VSTR:
         s += "\"" + json_escape(val) + "\"";
         break;
+    case VREAL:
+        {
+            std::stringstream ss;
+            ss << std::showpoint << std::fixed << std::setprecision(8) << get_real();
+            s += ss.str();
+        }
+        break;
     case VNUM:
         s += val;
         break;