update to a new version of ff crate with serde support

Cargo.toml

@@ -2,11 +2,12 @@
 name = "pairing"
 
 # Remember to change version string in README.md.
-version = "0.15.0"
+version = "0.15.1"
 authors = [
     "Sean Bowe <ewillbefull@gmail.com>",
     "Jack Grigg <jack@z.cash>",
-    "Alex Vlasov <alex.m.vlasov@gmail.com>"
+    "Alex Vlasov <alex.m.vlasov@gmail.com>",
+    "Alex Gluchowski <alex@gluchowski.net>"
 ]
 license = "MIT/Apache-2.0"
 
@@ -18,7 +19,12 @@ repository = "https://github.com/matterinc/pairing"
 [dependencies]
 rand = "0.4"
 byteorder = "1"
-ff = { version = "0.4", features = ["derive"] }
+ff = { git = 'https://github.com/matterinc/ff', features = ["derive"] }
+#ff = { path = "../ff", features = ["derive"] }
+serde = "1.0.80"
+serde_derive = "1.0.80"
+serde_json = "1.0.33"
+hex = "0.3.2"
 
 [features]
 unstable-features = ["expose-arith"]

src/bn256/fr.rs

@@ -5,7 +5,49 @@ use ff::{Field, PrimeField, PrimeFieldDecodingError, PrimeFieldRepr};
 #[PrimeFieldGenerator = "7"]
 pub struct Fr(FrRepr);
 
+#[test]
+fn test_to_hex() {
+    assert_eq!(Fr::one().to_hex(), "0000000000000000000000000000000000000000000000000000000000000001");
+}
+
+#[test]
+fn test_fr_from_hex() {
+    let fr = Fr::from_hex("0000000000000000000000000000000000000000000000000000000000000001").unwrap();
+    assert_eq!(fr, Fr::one());
+
+    let fr = Fr::from_hex("0x0000000000000000000000000000000000000000000000000000000000000001").unwrap();
+    assert_eq!(fr, Fr::one());
+
+    let fr = Fr::from_hex("0x01").unwrap();
+    assert_eq!(fr, Fr::one());
+
+    let fr = Fr::from_hex("0x00").unwrap();
+    assert_eq!(fr, Fr::zero());
+
+    let fr = Fr::from_hex("00").unwrap();
+    assert_eq!(fr, Fr::zero());
+}
+
+#[test]
+fn test_fr_serialize() {
+    assert_eq!(
+        serde_json::to_string(&Fr::one()).unwrap(), 
+        r#""0x0000000000000000000000000000000000000000000000000000000000000001""#);
+}
+
+#[test]
+fn test_fr_deserialize() {
+    let json = r#""0x0000000000000000000000000000000000000000000000000000000000000001""#;
+    let fr: Fr = serde_json::from_str(json).unwrap();
+    assert_eq!(fr, Fr::one());
+}
+
 #[test]
 fn test_roots_of_unity() {
     assert_eq!(Fr::S, 28);
 }
+
+#[test]
+fn test_default() {
+    assert_eq!(Fr::default(), Fr::zero());
+}

src/lib.rs

@@ -15,6 +15,11 @@ extern crate byteorder;
 extern crate ff;
 extern crate rand;
 
+extern crate hex;
+extern crate serde;
+#[macro_use]
+extern crate serde_derive;
+
 #[cfg(test)]
 pub mod tests;