Add Provider trait

src/lib.rs

@@ -4,3 +4,4 @@ extern crate rustc_serialize;
 extern crate url;
 
 pub mod token;
+pub mod provider;

src/provider.rs

@@ -0,0 +1,22 @@
+//! Providers.
+
+use token::{Token, Lifetime};
+
+/// OAuth 2.0 providers.
+pub trait Provider {
+    /// The lifetime of tokens issued by the provider.
+    type Lifetime: Lifetime;
+
+    /// The type of token issued by the provider.
+    type Token: Token<Self::Lifetime>;
+
+    /// The authorization endpoint URI.
+    ///
+    /// See [RFC 6749, section 3.1](http://tools.ietf.org/html/rfc6749#section-3.1).
+    fn auth_uri() -> &'static str;
+
+    /// The token endpoint URI.
+    ///
+    /// See [RFC 6749, section 3.2](http://tools.ietf.org/html/rfc6749#section-3.2).
+    fn token_uri() -> &'static str;
+}