feat(headers): adds Accept

Moved utils to shared/. Added quality_value.

src/header/shared/encoding.rs

@@ -0,0 +1,50 @@
+//! Provides an Encoding enum.
+
+use std::fmt;
+use std::str;
+
+pub use self::Encoding::{Chunked, Gzip, Deflate, Compress, Identity, EncodingExt};
+
+/// A value to represent an encoding used in `Transfer-Encoding`
+/// or `Accept-Encoding` header.
+#[deriving(Clone, PartialEq)]
+pub enum Encoding {
+    /// The `chunked` encoding.
+    Chunked,
+    /// The `gzip` encoding.
+    Gzip,
+    /// The `deflate` encoding.
+    Deflate,
+    /// The `compress` encoding.
+    Compress,
+    /// The `identity` encoding.
+    Identity,
+    /// Some other encoding that is less common, can be any String.
+    EncodingExt(String)
+}
+
+impl fmt::Show for Encoding {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Chunked => "chunked",
+            Gzip => "gzip",
+            Deflate => "deflate",
+            Compress => "compress",
+            Identity => "identity",
+            EncodingExt(ref s) => s.as_slice()
+            }.fmt(fmt)
+        }
+    }
+
+impl str::FromStr for Encoding {
+    fn from_str(s: &str) -> Option<Encoding> {
+        match s {
+            "chunked" => Some(Chunked),
+            "deflate" => Some(Deflate),
+            "gzip" => Some(Gzip),
+            "compress" => Some(Compress),
+            "identity" => Some(Identity),
+            _ => Some(EncodingExt(s.to_string()))
+        }
+    }
+}