0.5: Support floats nan, inf, and +/-0.0.

cc #224

src/de.rs

@@ -6,6 +6,7 @@
 
 use std::borrow::Cow;
 use std::error;
+use std::f64;
 use std::fmt;
 use std::str;
 use std::vec;
@@ -882,6 +883,14 @@ impl<'a> Deserializer<'a> {
                 }
                 _ => Err(self.error(at, ErrorKind::NumberInvalid)),
             }
+        } else if s == "inf" {
+            Ok(Value { e: E::Float(f64::INFINITY), start: start, end: end })
+        } else if s == "-inf" {
+            Ok(Value { e: E::Float(f64::NEG_INFINITY), start: start, end: end })
+        } else if s == "nan" {
+            Ok(Value { e: E::Float(f64::NAN), start: start, end: end })
+        } else if s == "-nan" {
+            Ok(Value { e: E::Float(-f64::NAN), start: start, end: end })
         } else {
             self.integer(s).map(|f| Value { e: E::Integer(f), start: start, end: end })
         }

src/ser.rs

@@ -737,6 +737,27 @@ impl<'a> Serializer<'a> {
     }
 }
 
+macro_rules! serialize_float {
+    ($this:expr, $v:expr) => {{
+        $this.emit_key("float")?;
+        if ($v.is_nan() || $v == 0.0) && $v.is_sign_negative() {
+            drop(write!($this.dst, "-"));
+        }
+        if $v.is_nan() {
+            drop(write!($this.dst, "nan"));
+        } else {
+            drop(write!($this.dst, "{}", $v));
+        }
+        if $v % 1.0 == 0.0 {
+            drop(write!($this.dst, ".0"));
+        }
+        if let State::Table { .. } = $this.state {
+            $this.dst.push_str("\n");
+        }
+        return Ok(());
+    }};
+}
+
 impl<'a, 'b> ser::Serializer for &'b mut Serializer<'a> {
     type Ok = ();
     type Error = Error;
@@ -785,35 +806,11 @@ impl<'a, 'b> ser::Serializer for &'b mut Serializer<'a> {
     }
 
     fn serialize_f32(self, v: f32) -> Result<(), Self::Error> {
-        if !v.is_finite() {
-            return Err(Error::NumberInvalid);
-        }
-
-        self.emit_key("float")?;
-        drop(write!(self.dst, "{}", v));
-        if v % 1.0 == 0.0 {
-            drop(write!(self.dst, ".0"));
-        }
-        if let State::Table { .. } = self.state {
-            self.dst.push_str("\n");
-        }
-        Ok(())
+        serialize_float!(self, v)
     }
 
     fn serialize_f64(self, v: f64) -> Result<(), Self::Error> {
-        if !v.is_finite() {
-            return Err(Error::NumberInvalid);
-        }
-
-        self.emit_key("float")?;
-        drop(write!(self.dst, "{}", v));
-        if v % 1.0 == 0.0 {
-            drop(write!(self.dst, ".0"));
-        }
-        if let State::Table { .. } = self.state {
-            self.dst.push_str("\n");
-        }
-        Ok(())
+        serialize_float!(self, v)
     }
 
     fn serialize_char(self, v: char) -> Result<(), Self::Error> {

test-suite/build.rs

@@ -4,5 +4,6 @@ use rustc_version::{version, Version};
 fn main() {
     if version().unwrap() >= Version::parse("1.20.0").unwrap() {
         println!(r#"cargo:rustc-cfg=feature="test-quoted-keys-in-macro""#);
+        println!(r#"cargo:rustc-cfg=feature="test-nan-sign""#);
     }
 }

test-suite/tests/float.rs

@@ -0,0 +1,79 @@
+extern crate toml;
+#[macro_use]
+extern crate serde_derive;
+
+use toml::Value;
+
+macro_rules! float_inf_tests {
+    ($ty:ty) => {{
+        #[derive(Serialize, Deserialize)]
+        struct S {
+            sf1: $ty,
+            sf2: $ty,
+            sf3: $ty,
+            sf4: $ty,
+            sf5: $ty,
+            sf6: $ty,
+            sf7: $ty,
+            sf8: $ty,
+        }
+        let inf: S = toml::from_str(
+            r"
+        # infinity
+        sf1 = inf  # positive infinity
+        sf2 = +inf # positive infinity
+        sf3 = -inf # negative infinity
+
+        # not a number
+        sf4 = nan  # actual sNaN/qNaN encoding is implementation specific
+        sf5 = +nan # same as `nan`
+        sf6 = -nan # valid, actual encoding is implementation specific
+
+        # zero
+        sf7 = +0.0
+        sf8 = -0.0
+        ").expect("Parse infinities.");
+
+        assert!(inf.sf1.is_infinite());
+        assert!(inf.sf1.is_sign_positive());
+        assert!(inf.sf2.is_infinite());
+        assert!(inf.sf2.is_sign_positive());
+        assert!(inf.sf3.is_infinite());
+        assert!(inf.sf3.is_sign_negative());
+
+        assert!(inf.sf4.is_nan());
+        assert!(inf.sf4.is_sign_positive());
+        assert!(inf.sf5.is_nan());
+        assert!(inf.sf5.is_sign_positive());
+        assert!(inf.sf6.is_nan());
+        assert!(inf.sf6.is_sign_negative());
+
+        assert_eq!(inf.sf7, 0.0);
+        assert!(inf.sf7.is_sign_positive());
+        assert_eq!(inf.sf8, 0.0);
+        assert!(inf.sf8.is_sign_negative());
+
+        let s = toml::to_string(&inf).unwrap();
+        assert_eq!(
+            s, "\
+sf1 = inf
+sf2 = inf
+sf3 = -inf
+sf4 = nan
+sf5 = nan
+sf6 = -nan
+sf7 = 0.0
+sf8 = -0.0
+"
+        );
+
+        toml::from_str::<Value>(&s).expect("roundtrip");
+    }};
+}
+
+#[test]
+#[cfg(feature = "test-nan-sign")]
+fn float_inf() {
+    float_inf_tests!(f32);
+    float_inf_tests!(f64);
+}

test-suite/tests/invalid-encoder-misc.rs

@@ -1,14 +0,0 @@
-extern crate toml;
-
-use std::f64;
-
-#[test]
-fn test_invalid_float_encode() {
-    fn bad(value: toml::Value) {
-        assert!(toml::to_string(&value).is_err());
-    }
-
-    bad(toml::Value::Float(f64::INFINITY));
-    bad(toml::Value::Float(f64::NEG_INFINITY));
-    bad(toml::Value::Float(f64::NAN));
-}

test-suite/tests/invalid-misc.rs

@@ -10,8 +10,5 @@ fn bad() {
     bad("a = 1__1");
     bad("a = 1_");
     bad("''");
-    bad("a = nan");
-    bad("a = -inf");
-    bad("a = inf");
     bad("a = 9e99999");
 }

test-suite/tests/valid/integer.json

@@ -1,4 +1,6 @@
 {
     "answer": {"type": "integer", "value": "42"},
-    "neganswer": {"type": "integer", "value": "-42"}
+    "neganswer": {"type": "integer", "value": "-42"},
+    "neg_zero": {"type": "integer", "value": "0"},
+    "pos_zero": {"type": "integer", "value": "0"}
 }

test-suite/tests/valid/integer.toml

@@ -1,2 +1,4 @@
 answer = 42
 neganswer = -42
+neg_zero = -0
+pos_zero = +0