number: Add support for nan

Signed-off-by: Patrick José Pereira <[email protected]>

Author: patrickelectric

src/number.rs

@@ -145,9 +145,10 @@ impl Number {
     /// ```
     /// # use serde_json::json;
     /// #
-    /// let v = json!({ "a": 256.0, "b": 64, "c": -64 });
+    /// let v = json!({ "a": 256.0, "b": 64, "c": -64, "d": nan });
     ///
     /// assert!(v["a"].is_f64());
+    /// assert!(v["d"].is_f64());
     ///
     /// // Integers.
     /// assert!(!v["b"].is_f64());
@@ -230,11 +231,12 @@ impl Number {
     /// ```
     /// # use serde_json::json;
     /// #
-    /// let v = json!({ "a": 256.0, "b": 64, "c": -64 });
+    /// let v = json!({ "a": 256.0, "b": 64, "c": -64, "d": nan });
     ///
     /// assert_eq!(v["a"].as_f64(), Some(256.0));
     /// assert_eq!(v["b"].as_f64(), Some(64.0));
     /// assert_eq!(v["c"].as_f64(), Some(-64.0));
+    /// assert!(v["d"].as_f64().unwrap().is_nan());
     /// ```
     #[inline]
     pub fn as_f64(&self) -> Option<f64> {
@@ -245,7 +247,7 @@ impl Number {
             N::Float(n) => Some(n),
         }
         #[cfg(feature = "arbitrary_precision")]
-        self.n.parse::<f64>().ok().filter(|float| float.is_finite())
+        self.n.parse::<f64>().ok().filter(|float| !float.is_infinite())
     }
 
     /// Converts a finite `f64` to a `Number`. Infinite or NaN values are not JSON
@@ -258,7 +260,9 @@ impl Number {
     /// #
     /// assert!(Number::from_f64(256.0).is_some());
     ///
-    /// assert!(Number::from_f64(f64::NAN).is_none());
+    /// assert!(Number::from_f64(f64::NAN).is_some());
+    ///
+    /// assert!(Number::from_f64(f64::INFINITY).is_none());
     /// ```
     #[inline]
     pub fn from_f64(f: f64) -> Option<Number> {
@@ -275,6 +279,14 @@ impl Number {
             };
             Some(Number { n })
         } else {
+            #[cfg(not(feature = "arbitrary_precision"))]
+            {
+                if f.is_nan() {
+                    return Some(Number {
+                        n: N::Float(f64::NAN),
+                    });
+                }
+            }
             None
         }
     }
@@ -294,7 +306,7 @@ impl Display for Number {
         match self.n {
             N::PosInt(u) => formatter.write_str(itoa::Buffer::new().format(u)),
             N::NegInt(i) => formatter.write_str(itoa::Buffer::new().format(i)),
-            N::Float(f) => formatter.write_str(ryu::Buffer::new().format_finite(f)),
+            N::Float(f) => formatter.write_str(ryu::Buffer::new().format(f)),
         }
     }