feat(headers): Implement Content-Language header field

Closes #475

src/header/common/accept_language.rs

@@ -1,39 +1,4 @@
-use header::QualityItem;
-use std::str::FromStr;
-use std::fmt;
-
-/// A language tag.
-/// See http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.10
-#[derive(Clone, PartialEq, Debug)]
-pub struct Language{
-    primary: String,
-    sub: Option<String>
-}
-
-impl FromStr for Language {
-    type Err = ();
-    fn from_str(s: &str) -> Result<Language, ()> {
-        let mut i = s.split("-");
-        let p = i.next();
-        let s = i.next();
-        match (p, s) {
-            (Some(p),Some(s)) => Ok(Language{primary: p.to_string(),
-                                             sub: Some(s.to_string())}),
-            (Some(p),_) => Ok(Language{primary: p.to_string(), sub: None}),
-            _ => Err(())
-        }
-    }
-}
-
-impl fmt::Display for Language {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        try!(write!(f, "{}", self.primary));
-        match self.sub {
-            Some(ref s) => write!(f, "-{}", s),
-            None => Ok(())
-        }
-    }
-}
+use header::{Language, QualityItem};
 
 header! {
     #[doc="`Accept-Language` header, defined in"]
@@ -57,7 +22,7 @@ header! {
 
 #[cfg(test)]
 mod tests {
-    use header::{Header, qitem, Quality, QualityItem};
+    use header::{Header, Language, qitem, Quality, QualityItem};
     use super::*;
 
     #[test]

src/header/common/content_language.rs

@@ -0,0 +1,22 @@
+use header::{Language, QualityItem};
+
+header! {
+    #[doc="`Content-Language` header, defined in"]
+    #[doc="[RFC7231](https://tools.ietf.org/html/rfc7231#section-3.1.3.2)"]
+    #[doc=""]
+    #[doc="The `Content-Language` header field describes the natural language(s)"]
+    #[doc="of the intended audience for the representation.  Note that this"]
+    #[doc="might not be equivalent to all the languages used within the"]
+    #[doc="representation."]
+    #[doc=""]
+    #[doc="# ABNF"]
+    #[doc="```plain"]
+    #[doc="Content-Language = 1#language-tag"]
+    #[doc="```"]
+    (ContentLanguage, "Content-Language") => (QualityItem<Language>)+
+
+    test_content_language {
+        test_header!(test1, vec![b"da"]);
+        test_header!(test2, vec![b"mi, en"]);
+    }
+}

src/header/common/mod.rs

@@ -22,6 +22,7 @@ pub use self::cache_control::{CacheControl, CacheDirective};
 pub use self::connection::{Connection, ConnectionOption};
 pub use self::content_length::ContentLength;
 pub use self::content_encoding::ContentEncoding;
+pub use self::content_language::ContentLanguage;
 pub use self::content_type::ContentType;
 pub use self::cookie::Cookie;
 pub use self::date::Date;
@@ -303,6 +304,7 @@ mod cache_control;
 mod cookie;
 mod connection;
 mod content_encoding;
+mod content_language;
 mod content_length;
 mod content_type;
 mod date;