Rename the xmpp-parsers directory to parsers

This doesn’t change anything to the name of the crate, just makes
autocompletion easier by not sharing the same prefix as the xmpp crate.

parsers/src/jingle_rtcp_fb.rs

@@ -0,0 +1,47 @@
+// Copyright (c) 2019 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// 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/.
+
+generate_element!(
+    /// Wrapper element for a rtcp-fb.
+    RtcpFb, "rtcp-fb", JINGLE_RTCP_FB,
+    attributes: [
+        /// Type of this rtcp-fb.
+        type_: Required<String> = "type",
+
+        /// Subtype of this rtcp-fb, if relevant.
+        subtype: Option<String> = "subtype",
+    ]
+);
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::Element;
+    use std::convert::TryFrom;
+
+    #[cfg(target_pointer_width = "32")]
+    #[test]
+    fn test_size() {
+        assert_size!(RtcpFb, 24);
+    }
+
+    #[cfg(target_pointer_width = "64")]
+    #[test]
+    fn test_size() {
+        assert_size!(RtcpFb, 48);
+    }
+
+    #[test]
+    fn parse_simple() {
+        let elem: Element =
+            "<rtcp-fb xmlns='urn:xmpp:jingle:apps:rtp:rtcp-fb:0' type='nack' subtype='sli'/>"
+                .parse()
+                .unwrap();
+        let rtcp_fb = RtcpFb::try_from(elem).unwrap();
+        assert_eq!(rtcp_fb.type_, "nack");
+        assert_eq!(rtcp_fb.subtype.unwrap(), "sli");
+    }
+}