Merge pull request #152 from rust-bitcoin/2018-08-script-ord

impl PartialOrd, Ord for Script

src/blockdata/script.rs

@@ -41,7 +41,7 @@ use util::hash::Hash160;
 #[cfg(feature="fuzztarget")]      use util::sha2::Sha256;
 #[cfg(not(feature="fuzztarget"))] use crypto::sha2::Sha256;
 
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, Default, PartialOrd, Ord, PartialEq, Eq, Hash)]
 /// A Bitcoin script
 pub struct Script(Box<[u8]>);
 
@@ -399,10 +399,6 @@ impl Script {
     }
 }
 
-impl Default for Script {
-    fn default() -> Script { Script(vec![].into_boxed_slice()) }
-}
-
 /// Creates a new script from an existing vector
 impl From<Vec<u8>> for Script {
     fn from(v: Vec<u8>) -> Script { Script(v.into_boxed_slice()) }
@@ -903,6 +899,25 @@ mod test {
         assert_eq!(v_nonmin_alt, slop_v_nonmin_alt);
     }
 
+	#[test]
+    fn script_ord() {
+        let script_1 = Builder::new().push_slice(&[1,2,3,4]).into_script();
+        let script_2 = Builder::new().push_int(10).into_script();
+        let script_3 = Builder::new().push_int(15).into_script();
+        let script_4 = Builder::new().push_opcode(opcodes::All::OP_RETURN).into_script();
+
+        assert!(script_1 < script_2);
+        assert!(script_2 < script_3);
+        assert!(script_3 < script_4);
+
+        assert!(script_1 <= script_1);
+        assert!(script_1 >= script_1);
+
+        assert!(script_4 > script_3);
+        assert!(script_3 > script_2);
+        assert!(script_2 > script_1);
+    }
+
 	#[test]
 	#[cfg(feature="bitcoinconsensus")]
 	fn test_bitcoinconsensus () {