eme: Switch to Into/TryFrom.

src/eme.rs

@@ -4,6 +4,8 @@
 // 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;
@@ -16,44 +18,48 @@ pub struct ExplicitMessageEncryption {
     pub name: Option<String>,
 }
 
-pub fn parse_explicit_message_encryption(root: &Element) -> Result<ExplicitMessageEncryption, Error> {
-    if !root.is("encryption", ns::EME) {
+impl<'a> TryFrom<&'a Element> for ExplicitMessageEncryption {
+    type Error = Error;
+
+    fn try_from(elem: &'a Element) -> Result<ExplicitMessageEncryption, Error> {
+        if !elem.is("encryption", ns::EME) {
             return Err(Error::ParseError("This is not an encryption element."));
         }
-    for _ in root.children() {
+        for _ in elem.children() {
             return Err(Error::ParseError("Unknown child in encryption element."));
         }
-    let namespace = root.attr("namespace").ok_or(Error::ParseError("Mandatory argument 'namespace' not present in encryption element."))?.to_owned();
-    let name = root.attr("name").and_then(|value| value.parse().ok());
+        let namespace = elem.attr("namespace").ok_or(Error::ParseError("Mandatory argument 'namespace' not present in encryption element."))?.to_owned();
+        let name = elem.attr("name").and_then(|value| value.parse().ok());
         Ok(ExplicitMessageEncryption {
             namespace: namespace,
             name: name,
         })
     }
+}
 
-pub fn serialise(eme: &ExplicitMessageEncryption) -> Element {
+impl<'a> Into<Element> for &'a ExplicitMessageEncryption {
+    fn into(self) -> Element {
         Element::builder("encryption")
                 .ns(ns::EME)
-            .attr("namespace", eme.namespace.clone())
-            .attr("name", eme.name.clone())
+                .attr("namespace", self.namespace.clone())
+                .attr("name", self.name.clone())
                 .build()
     }
+}
 
 #[cfg(test)]
 mod tests {
-    use minidom::Element;
-    use error::Error;
-    use eme;
+    use super::*;
 
     #[test]
     fn test_simple() {
         let elem: Element = "<encryption xmlns='urn:xmpp:eme:0' namespace='urn:xmpp:otr:0'/>".parse().unwrap();
-        let encryption = eme::parse_explicit_message_encryption(&elem).unwrap();
+        let encryption = ExplicitMessageEncryption::try_from(&elem).unwrap();
         assert_eq!(encryption.namespace, "urn:xmpp:otr:0");
         assert_eq!(encryption.name, None);
 
         let elem: Element = "<encryption xmlns='urn:xmpp:eme:0' namespace='some.unknown.mechanism' name='SuperMechanism'/>".parse().unwrap();
-        let encryption = eme::parse_explicit_message_encryption(&elem).unwrap();
+        let encryption = ExplicitMessageEncryption::try_from(&elem).unwrap();
         assert_eq!(encryption.namespace, "some.unknown.mechanism");
         assert_eq!(encryption.name, Some(String::from("SuperMechanism")));
     }
@@ -61,7 +67,7 @@ mod tests {
     #[test]
     fn test_unknown() {
         let elem: Element = "<replace xmlns='urn:xmpp:message-correct:0'/>".parse().unwrap();
-        let error = eme::parse_explicit_message_encryption(&elem).unwrap_err();
+        let error = ExplicitMessageEncryption::try_from(&elem).unwrap_err();
         let message = match error {
             Error::ParseError(string) => string,
             _ => panic!(),
@@ -72,7 +78,7 @@ mod tests {
     #[test]
     fn test_invalid_child() {
         let elem: Element = "<encryption xmlns='urn:xmpp:eme:0'><coucou/></encryption>".parse().unwrap();
-        let error = eme::parse_explicit_message_encryption(&elem).unwrap_err();
+        let error = ExplicitMessageEncryption::try_from(&elem).unwrap_err();
         let message = match error {
             Error::ParseError(string) => string,
             _ => panic!(),
@@ -83,8 +89,8 @@ mod tests {
     #[test]
     fn test_serialise() {
         let elem: Element = "<encryption xmlns='urn:xmpp:eme:0' namespace='coucou'/>".parse().unwrap();
-        let eme = eme::ExplicitMessageEncryption { namespace: String::from("coucou"), name: None };
-        let elem2 = eme::serialise(&eme);
+        let eme = ExplicitMessageEncryption { namespace: String::from("coucou"), name: None };
+        let elem2 = (&eme).into();
         assert_eq!(elem, elem2);
     }
 }

src/message.rs

@@ -22,7 +22,7 @@ use receipts::Receipt;
 use delay::Delay;
 use attention::Attention;
 use message_correct::Replace;
-use eme;
+use eme::ExplicitMessageEncryption;
 
 /// Lists every known payload of a `<message/>`.
 #[derive(Debug, Clone)]
@@ -34,7 +34,7 @@ pub enum MessagePayload {
     Delay(Delay),
     Attention(Attention),
     MessageCorrect(Replace),
-    ExplicitMessageEncryption(eme::ExplicitMessageEncryption),
+    ExplicitMessageEncryption(ExplicitMessageEncryption),
 }
 
 #[derive(Debug, Clone, PartialEq)]
@@ -125,7 +125,7 @@ pub fn parse_message(root: &Element) -> Result<Message, Error> {
             Some(MessagePayload::Attention(attention))
         } else if let Ok(replace) = Replace::try_from(elem) {
             Some(MessagePayload::MessageCorrect(replace))
-        } else if let Ok(eme) = eme::parse_explicit_message_encryption(elem) {
+        } else if let Ok(eme) = ExplicitMessageEncryption::try_from(elem) {
             Some(MessagePayload::ExplicitMessageEncryption(eme))
         } else {
             None
@@ -153,7 +153,7 @@ pub fn serialise_payload(payload: &MessagePayload) -> Element {
         MessagePayload::Receipt(ref receipt) => receipt.into(),
         MessagePayload::Delay(ref delay) => delay.into(),
         MessagePayload::MessageCorrect(ref replace) => replace.into(),
-        MessagePayload::ExplicitMessageEncryption(ref eme) => eme::serialise(eme),
+        MessagePayload::ExplicitMessageEncryption(ref eme) => eme.into(),
     }
 }