From be7b7d32337a908829814e2ee417bb33cff570a0 Mon Sep 17 00:00:00 2001
From: Aaron Weiss <aaronweiss74@gmail.com>
Date: Thu, 21 May 2015 22:32:23 -0400
Subject: [PATCH] Added Capability for a type-safe IRCv3 CAP REQ API.

---
 src/client/data/caps.rs    | 31 +++++++++++++++++++++++++++++++
 src/client/data/mod.rs     |  2 ++
 src/client/mod.rs          |  2 +-
 src/client/server/utils.rs |  9 +++++++--
 4 files changed, 41 insertions(+), 3 deletions(-)
 create mode 100644 src/client/data/caps.rs

diff --git a/src/client/data/caps.rs b/src/client/data/caps.rs
new file mode 100644
index 0000000..b310644
--- /dev/null
+++ b/src/client/data/caps.rs
@@ -0,0 +1,31 @@
+//! Enumeration of all supported IRCv3 capability extensions.
+
+/// List of all supported IRCv3 capability extensions from the
+/// [IRCv3 specifications](http://ircv3.net/irc/). 
+#[derive(Debug, PartialEq)]
+pub enum Capability {
+    /// [multi-prefix](http://ircv3.net/specs/extensions/multi-prefix-3.1.html)
+    MultiPrefix,
+    /// [account-notify](http://ircv3.net/specs/extensions/account-notify-3.1.html)
+    AccountNotify,
+}
+
+impl AsRef<str> for Capability {
+    fn as_ref(&self) -> &str {
+        match *self {
+            Capability::MultiPrefix => "multi-prefix",
+            Capability::AccountNotify => "account-notify",
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::Capability::*;
+
+    #[test]
+    fn to_str() {
+        assert_eq!(MultiPrefix.as_ref(), "multi-prefix");
+        assert_eq!(AccountNotify.as_ref(), "account-notify");
+    }
+}
diff --git a/src/client/data/mod.rs b/src/client/data/mod.rs
index 22bbe96..eddba9d 100644
--- a/src/client/data/mod.rs
+++ b/src/client/data/mod.rs
@@ -1,5 +1,6 @@
 //! Data related to IRC functionality.
 
+pub use client::data::caps::Capability;
 pub use client::data::command::Command;
 pub use client::data::config::Config;
 pub use client::data::message::Message;
@@ -18,6 +19,7 @@ pub mod kinds {
     impl<T> IrcRead for T where T: BufRead + Sized + Send + 'static {}
 }
 
+pub mod caps;
 pub mod command;
 pub mod config;
 pub mod message;
diff --git a/src/client/mod.rs b/src/client/mod.rs
index bc02e81..08b1e4f 100644
--- a/src/client/mod.rs
+++ b/src/client/mod.rs
@@ -8,7 +8,7 @@ pub mod prelude {
     //! A client-side IRC prelude, re-exporting all the necessary basics.
     pub use client::server::{IrcServer, Server};
     pub use client::server::utils::ServerExt;
-    pub use client::data::{Command, Config, Message, Response};
+    pub use client::data::{Capability, Command, Config, Message, Response};
     pub use client::data::kinds::{IrcRead, IrcWrite};
 }
 
diff --git a/src/client/server/utils.rs b/src/client/server/utils.rs
index 2ace5db..922c876 100644
--- a/src/client/server/utils.rs
+++ b/src/client/server/utils.rs
@@ -1,6 +1,7 @@
 //! Utilities and shortcuts for working with IRC servers.
 use std::io::Result;
 use std::borrow::ToOwned;
+use client::data::Capability;
 use client::data::Command::{CAP, INVITE, JOIN, KICK, KILL, MODE, NICK, NOTICE};
 use client::data::Command::{OPER, PASS, PONG, PRIVMSG, QUIT, SAMODE, SANICK, TOPIC, USER};
 use client::data::command::CapSubCommand::{END, REQ};
@@ -11,8 +12,12 @@ use client::server::Server;
 /// Extensions for Server capabilities that make it easier to work directly with the protocol.
 pub trait ServerExt<'a, T, U>: Server<'a, T, U> {
     /// Sends an IRCv3 capabilities request for the specified extensions.
-    fn send_cap_req(&self, extensions: &str) -> Result<()> {
-        self.send(CAP(None, REQ, None, Some(extensions.to_owned())))
+    fn send_cap_req(&self, extensions: &[Capability]) -> Result<()> {
+        let append = |mut s: String, c| { s.push_str(c); s.push(' '); s };
+        let mut exts = extensions.iter().map(|c| c.as_ref()).fold(String::new(), append);
+        let len = exts.len() - 1;
+        exts.truncate(len);
+        self.send(CAP(None, REQ, None, Some(exts)))
     }
 
     /// Sends a CAP END, NICK and USER to identify.