Allow use of faster floating-point number serialization (StreamWriteFeature.USE_FAST_DOUBLE_WRITER)

pom.xml

@@ -37,11 +37,11 @@
     <!-- 04-Mar-2019, tatu: Retain Java6/JDK1.6 compatibility for annotations for Jackson 2.x,
              but use Moditect to get JDK9+ module info support; need newer bundle plugin as well
       -->
-    <javac.src.version>1.6</javac.src.version>
-    <javac.target.version>1.6</javac.target.version>
+    <javac.src.version>1.8</javac.src.version>
+    <javac.target.version>1.8</javac.target.version>
 
-    <maven.compiler.source>1.6</maven.compiler.source>
-    <maven.compiler.target>1.6</maven.compiler.target>
+    <maven.compiler.source>1.8</maven.compiler.source>
+    <maven.compiler.target>1.8</maven.compiler.target>
 
     <osgi.export>com.fasterxml.jackson.core;version=${project.version},
 com.fasterxml.jackson.core.*;version=${project.version}

src/main/java/com/fasterxml/jackson/core/io/NumberOutput.java

@@ -1,5 +1,8 @@
 package com.fasterxml.jackson.core.io;
 
+import com.fasterxml.jackson.core.io.schubfach.DoubleToDecimal;
+import com.fasterxml.jackson.core.io.schubfach.FloatToDecimal;
+
 public final class NumberOutput
 {
     private static int MILLION = 1000000;
@@ -274,12 +277,12 @@ public static String toString(long v) {
     }
 
     public static String toString(double v) {
-        return Double.toString(v);
+        return DoubleToDecimal.toString(v);
     }
 
     // @since 2.6
     public static String toString(float v) {
-        return Float.toString(v);
+        return FloatToDecimal.toString(v);
     }
 
     /*

src/main/java/com/fasterxml/jackson/core/io/ryu/RoundingMode.java

@@ -0,0 +1,47 @@
+
+// Copyright 2018 Ulf Adams
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.fasterxml.jackson.core.io.ryu;
+
+/**
+ * This is an internal class, public only for internal testing
+ */
+public enum RoundingMode {
+    CONSERVATIVE {
+        @Override
+        public boolean acceptUpperBound(boolean even) {
+            return false;
+        }
+
+        @Override
+        public boolean acceptLowerBound(boolean even) {
+            return false;
+        }
+    },
+    ROUND_EVEN {
+        @Override
+        public boolean acceptUpperBound(boolean even) {
+            return even;
+        }
+
+        @Override
+        public boolean acceptLowerBound(boolean even) {
+            return even;
+        }
+    };
+
+    public abstract boolean acceptUpperBound(boolean even);
+    public abstract boolean acceptLowerBound(boolean even);
+}