0.8.0 fixing #46, #45 and #42

Author: maciejhirsz

src/codegen.rs

@@ -1,4 +1,5 @@
 use std::io::Write;
+use std::num::FpCategory;
 use JsonValue;
 
 pub trait Generator {
@@ -57,8 +58,21 @@ pub trait Generator {
     }
 
     fn write_number(&mut self, mut num: f64) {
-        if num < 0.0 {
-            num = -num;
+        match num.classify() {
+            FpCategory::Nan      |
+            FpCategory::Infinite => {
+                self.write(b"null");
+                return;
+            },
+            FpCategory::Zero => {
+                self.write(if num.is_sign_negative() { b"-0" } else { b"0" });
+                return;
+            },
+            _ => {},
+        }
+
+        if num.is_sign_negative() {
+            num = num.abs();
             self.write_char(b'-');
         }
 

tests/lib.rs

@@ -1,6 +1,7 @@
 #[macro_use]
 extern crate json;
 
+use std::f64;
 use std::collections::BTreeMap;
 use std::collections::HashMap;
 use json::{ stringify, stringify_pretty, parse, JsonValue, JsonError, Null };
@@ -130,6 +131,37 @@ fn stringify_number() {
     assert_eq!(stringify(3.141592653589793), "3.141592653589793");
 }
 
+// #[test]
+// fn stringify_precise_positive_number() {
+//     assert_eq!(JsonValue::Number(1.2345f64).dump(), "1.2345");
+// }
+
+// #[test]
+// fn stringify_precise_negative_number() {
+//     assert_eq!(JsonValue::Number(-1.2345f64).dump(), "-1.2345");
+// }
+
+#[test]
+fn stringify_zero() {
+    assert_eq!(JsonValue::Number(0.0).dump(), "0");
+}
+
+#[test]
+fn stringify_nan() {
+    assert_eq!(JsonValue::Number(f64::NAN).dump(), "null");
+}
+
+#[test]
+fn stringify_infinity() {
+    assert_eq!(JsonValue::Number(f64::INFINITY).dump(), "null");
+    assert_eq!(JsonValue::Number(f64::NEG_INFINITY).dump(), "null");
+}
+
+#[test]
+fn stringify_negative_zero() {
+    assert_eq!(JsonValue::Number(-0f64).dump(), "-0");
+}
+
 #[test]
 fn stringify_integer() {
     assert_eq!(stringify(42), "42");
@@ -299,6 +331,11 @@ fn parse_integer() {
     assert_eq!(parse("42").unwrap(), 42);
 }
 
+#[test]
+fn parse_negative_zero() {
+    assert_eq!(parse("-0").unwrap(), JsonValue::Number(-0f64));
+}
+
 #[test]
 fn parse_negative_integer() {
     assert_eq!(parse("-42").unwrap(), -42);