Re-organize the client module

Re-organize the client module, creating a `gateway` submodule, and
splitting the connection into separate files in it.

The connection was a conglomeration of a number of purposes, most of
which are actually used elsewhere in the library and/or exposed to the
user. Thus, it makes sense to separate each item in a gateway-specific
module.

By splitting the client module further, this is a re-organization for
preliminary RPC support WRT the Client.

Additionally, rename the Connection struct to a Shard. The Connection
itself was not the actual connection, and was a higher-level interface
to the real connection logic. A Shard is a more accurate representation
of what it actually is.

1 files changed, 27 insertions, 0 deletions

diff --git a/src/client/gateway/error.rs b/src/client/gateway/error.rs
new file mode 100644
index 0000000..fb44d3f
--- /dev/null
+++ b/src/client/gateway/error.rs
@@ -0,0 +1,27 @@
+use std::fmt::{self, Display};
+
+#[derive(Clone, Debug)]
+pub enum Error {
+    /// The connection closed
+    Closed(Option<u16>, String),
+    /// Expected a Hello during a handshake
+    ExpectedHello,
+    /// Expected a Ready or an InvalidateSession
+    InvalidHandshake,
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Error::Closed(s, ref v) => {
+                f.write_str(&format!("Connection closed {:?}: {:?}", s, v))
+            },
+            Error::ExpectedHello => {
+                f.write_str("Expected Hello during handshake")
+            },
+            Error::InvalidHandshake => {
+                f.write_str("Expected Ready or InvalidateSession")
+            },
+        }
+    }
+}