ping: Port to TryFrom/Into.

src/ping.rs

@@ -5,6 +5,8 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+use std::convert::TryFrom;
+
 use minidom::Element;
 
 use error::Error;
@@ -14,37 +16,42 @@ use ns;
 #[derive(Debug, Clone)]
 pub struct Ping;
 
-pub fn parse_ping(root: &Element) -> Result<Ping, Error> {
-    if !root.is("ping", ns::PING) {
-        return Err(Error::ParseError("This is not a ping element."));
-    }
+impl<'a> TryFrom<&'a Element> for Ping {
+    type Error = Error;
 
-    for _ in root.children() {
-        return Err(Error::ParseError("Unknown child in ping element."));
+    fn try_from(elem: &'a Element) -> Result<Ping, Error> {
+        if !elem.is("ping", ns::PING) {
+            return Err(Error::ParseError("This is not a ping element."));
+        }
+        for _ in elem.children() {
+            return Err(Error::ParseError("Unknown child in ping element."));
+        }
+        Ok(Ping)
     }
-    Ok(Ping {  })
 }
 
-pub fn serialise_ping() -> Element {
-    Element::builder("ping").ns(ns::PING).build()
+impl<'a> Into<Element> for &'a Ping {
+    fn into(self) -> Element {
+        Element::builder("ping")
+                .ns(ns::PING)
+                .build()
+    }
 }
 
 #[cfg(test)]
 mod tests {
-    use minidom::Element;
-    use error::Error;
-    use ping;
+    use super::*;
 
     #[test]
     fn test_simple() {
         let elem: Element = "<ping xmlns='urn:xmpp:ping'/>".parse().unwrap();
-        ping::parse_ping(&elem).unwrap();
+        Ping::try_from(&elem).unwrap();
     }
 
     #[test]
     fn test_invalid() {
         let elem: Element = "<ping xmlns='urn:xmpp:ping'><coucou/></ping>".parse().unwrap();
-        let error = ping::parse_ping(&elem).unwrap_err();
+        let error = Ping::try_from(&elem).unwrap_err();
         let message = match error {
             Error::ParseError(string) => string,
             _ => panic!(),
@@ -56,7 +63,7 @@ mod tests {
     #[ignore]
     fn test_invalid_attribute() {
         let elem: Element = "<ping xmlns='urn:xmpp:ping' coucou=''/>".parse().unwrap();
-        let error = ping::parse_ping(&elem).unwrap_err();
+        let error = Ping::try_from(&elem).unwrap_err();
         let message = match error {
             Error::ParseError(string) => string,
             _ => panic!(),