Restructure modules

Modules are now separated into a fashion where the library can be used
for most use cases, without needing to compile the rest.

The core of serenity, with no features enabled, contains only the
struct (model) definitions, constants, and prelude. Models do not have
most functions compiled in, as that is separated into the `model`
feature.

The `client` module has been split into 3 modules: `client`, `gateway`,
and `http`.

`http` contains functions to interact with the REST API. `gateway`
contains the Shard to interact with the gateway, requiring `http` for
retrieving the gateway URL. `client` requires both of the other features
and acts as an abstracted interface over both the gateway and REST APIs,
handling the event loop.

The `builder` module has been separated from `utils`, and can now be
optionally compiled in. It and the `http` feature are required by the
`model` feature due to a large number of methods requiring access to
them.

`utils` now contains a number of utilities, such as the Colour struct, the
`MessageBuilder`, and mention parsing functions.

Each of the original `ext` modules are still featured, with `cache` not
requiring any feature to be enabled, `framework` requiring the `client`,
`model`, and `utils`, and `voice` requiring `gateway`.

In total the features and their requirements are:

- `builder`: none
- `cache`: none
- `client`: `gateway`, `http`
- `framework`: `client`, `model`, `utils`
- `gateway`: `http`
- `http`: none
- `model`: `builder`, `http`
- `utils`: none
- `voice`: `gateway`

The default features are `builder`, `cache`, `client`, `framework`,
`gateway`, `model`, `http`, and `utils`.

To help with forwards compatibility, modules have been re-exported from
their original locations.

1 files changed, 42 insertions, 45 deletions

diff --git a/src/model/channel/channel_id.rs b/src/model/channel/channel_id.rs
index 46b00c6..3967dba 100644
--- a/src/model/channel/channel_id.rs
+++ b/src/model/channel/channel_id.rs
@@ -1,12 +1,15 @@
 use std::fmt::{Display, Formatter, Result as FmtResult, Write as FmtWrite};
 use std::io::Read;
-use ::client::rest;
 use ::model::*;
-use ::utils::builder::{CreateMessage, EditChannel, GetMessages};
 
+#[cfg(feature="model")]
+use ::builder::{CreateMessage, EditChannel, GetMessages};
 #[cfg(feature="cache")]
-use ::client::CACHE;
+use ::CACHE;
+#[cfg(feature="model")]
+use ::http;
 
+#[cfg(feature="model")]
 impl ChannelId {
     /// Broadcasts that the current user is typing to a channel for the next 5
     /// seconds.
@@ -30,7 +33,7 @@ impl ChannelId {
     /// [Send Messages]: permissions/constant.SEND_MESSAGES.html
     #[inline]
     pub fn broadcast_typing(&self) -> Result<()> {
-        rest::broadcast_typing(self.0)
+        http::broadcast_typing(self.0)
     }
 
     /// Creates a [permission overwrite][`PermissionOverwrite`] for either a
@@ -60,7 +63,7 @@ impl ChannelId {
             "type": kind,
         });
 
-        rest::create_permission(self.0, id, &map)
+        http::create_permission(self.0, id, &map)
     }
 
     /// React to a [`Message`] with a custom [`Emoji`] or unicode character.
@@ -78,13 +81,13 @@ impl ChannelId {
     #[inline]
     pub fn create_reaction<M, R>(&self, message_id: M, reaction_type: R)
         -> Result<()> where M: Into<MessageId>, R: Into<ReactionType> {
-        rest::create_reaction(self.0, message_id.into().0, &reaction_type.into())
+        http::create_reaction(self.0, message_id.into().0, &reaction_type.into())
     }
 
     /// Deletes this channel, returning the channel on a successful deletion.
     #[inline]
     pub fn delete(&self) -> Result<Channel> {
-        rest::delete_channel(self.0)
+        http::delete_channel(self.0)
     }
 
     /// Deletes a [`Message`] given its Id.
@@ -99,7 +102,7 @@ impl ChannelId {
     /// [Manage Messages]: permissions/constant.MANAGE_MESSAGES.html
     #[inline]
     pub fn delete_message<M: Into<MessageId>>(&self, message_id: M) -> Result<()> {
-        rest::delete_message(self.0, message_id.into().0)
+        http::delete_message(self.0, message_id.into().0)
     }
 
     /// Deletes all messages by Ids from the given vector in the given channel.
@@ -125,7 +128,7 @@ impl ChannelId {
             "messages": ids
         });
 
-        rest::delete_messages(self.0, &map)
+        http::delete_messages(self.0, &map)
     }
 
     /// Deletes all permission overrides in the channel from a member or role.
@@ -134,7 +137,7 @@ impl ChannelId {
     ///
     /// [Manage Channel]: permissions/constant.MANAGE_CHANNELS.html
     pub fn delete_permission(&self, permission_type: PermissionOverwriteType) -> Result<()> {
-        rest::delete_permission(self.0, match permission_type {
+        http::delete_permission(self.0, match permission_type {
             PermissionOverwriteType::Member(id) => id.0,
             PermissionOverwriteType::Role(id) => id.0,
         })
@@ -149,7 +152,7 @@ impl ChannelId {
     /// [Manage Messages]: permissions/constant.MANAGE_MESSAGES.html
     pub fn delete_reaction<M, R>(&self, message_id: M, user_id: Option<UserId>, reaction_type: R)
         -> Result<()> where M: Into<MessageId>, R: Into<ReactionType> {
-        rest::delete_reaction(self.0,
+        http::delete_reaction(self.0,
                               message_id.into().0,
                               user_id.map(|uid| uid.0),
                               &reaction_type.into())
@@ -172,17 +175,11 @@ impl ChannelId {
     /// channel_id.edit(|c| c.name("test").bitrate(64000));
     /// ```
     ///
-    /// # Errors
-    ///
-    /// Returns a [`ClientError::NoChannelId`] if the current context is not
-    /// related to a channel.
-    ///
     /// [`Channel`]: enum.Channel.html
-    /// [`ClientError::NoChannelId`]: ../client/enum.ClientError.html#variant.NoChannelId
     /// [Manage Channel]: permissions/constant.MANAGE_CHANNELS.html
     #[inline]
     pub fn edit<F: FnOnce(EditChannel) -> EditChannel>(&self, f: F) -> Result<GuildChannel> {
-        rest::edit_channel(self.0, &f(EditChannel::default()).0)
+        http::edit_channel(self.0, &f(EditChannel::default()).0)
     }
 
     /// Edits a [`Message`] in the channel given its Id.
@@ -196,14 +193,14 @@ impl ChannelId {
     ///
     /// # Errors
     ///
-    /// Returns a [`ClientError::MessageTooLong`] if the content of the message
+    /// Returns a [`ModelError::MessageTooLong`] if the content of the message
     /// is over the [`the limit`], containing the number of unicode code points
     /// over the limit.
     ///
-    /// [`ClientError::MessageTooLong`]: ../client/enum.ClientError.html#variant.MessageTooLong
-    /// [`CreateMessage`]: ../utils/builder/struct.CreateMessage.html
+    /// [`ModelError::MessageTooLong`]: enum.ModelError.html#variant.MessageTooLong
+    /// [`CreateMessage`]: ../builder/struct.CreateMessage.html
     /// [`Message`]: struct.Message.html
-    /// [`the limit`]: ../utils/builder/struct.CreateMessage.html#method.content
+    /// [`the limit`]: ../builder/struct.CreateMessage.html#method.content
     pub fn edit_message<F, M>(&self, message_id: M, f: F) -> Result<Message>
         where F: FnOnce(CreateMessage) -> CreateMessage, M: Into<MessageId> {
         let map = f(CreateMessage::default()).0;
@@ -211,12 +208,12 @@ impl ChannelId {
         if let Some(content) = map.get("content") {
             if let Value::String(ref content) = *content {
                 if let Some(length_over) = Message::overflow_length(content) {
-                    return Err(Error::Client(ClientError::MessageTooLong(length_over)));
+                    return Err(Error::Model(ModelError::MessageTooLong(length_over)));
                 }
             }
         }
 
-        rest::edit_message(self.0, message_id.into().0, &Value::Object(map))
+        http::edit_message(self.0, message_id.into().0, &Value::Object(map))
     }
 
     /// Search the cache for the channel with the Id.
@@ -235,7 +232,7 @@ impl ChannelId {
             }
         }
 
-        rest::get_channel(self.0)
+        http::get_channel(self.0)
     }
 
     /// Gets all of the channel's invites.
@@ -244,7 +241,7 @@ impl ChannelId {
     /// [Manage Channels]: permissions/constant.MANAGE_CHANNELS.html
     #[inline]
     pub fn invites(&self) -> Result<Vec<RichInvite>> {
-        rest::get_channel_invites(self.0)
+        http::get_channel_invites(self.0)
     }
 
     /// Gets a message from the channel.
@@ -254,7 +251,7 @@ impl ChannelId {
     /// [Read Message History]: permissions/constant.READ_MESSAGE_HISTORY.html
     #[inline]
     pub fn message<M: Into<MessageId>>(&self, message_id: M) -> Result<Message> {
-        rest::get_message(self.0, message_id.into().0)
+        http::get_message(self.0, message_id.into().0)
             .map(|mut msg| {
                 msg.transform_content();
 
@@ -283,7 +280,7 @@ impl ChannelId {
             write!(query, "&before={}", before)?;
         }
 
-        rest::get_messages(self.0, &query)
+        http::get_messages(self.0, &query)
             .map(|msgs| msgs
                 .into_iter()
                 .map(|mut msg| {
@@ -298,7 +295,7 @@ impl ChannelId {
     /// [`Message`]: struct.Message.html
     #[inline]
     pub fn pin<M: Into<MessageId>>(&self, message_id: M) -> Result<()> {
-        rest::pin_message(self.0, message_id.into().0)
+        http::pin_message(self.0, message_id.into().0)
     }
 
     /// Gets the list of [`Message`]s which are pinned to the channel.
@@ -306,7 +303,7 @@ impl ChannelId {
     /// [`Message`]: struct.Message.html
     #[inline]
     pub fn pins(&self) -> Result<Vec<Message>> {
-        rest::get_pins(self.0)
+        http::get_pins(self.0)
     }
 
     /// Gets the list of [`User`]s who have reacted to a [`Message`] with a
@@ -329,7 +326,7 @@ impl ChannelId {
         -> Result<Vec<User>> where M: Into<MessageId>, R: Into<ReactionType>, U: Into<UserId> {
         let limit = limit.map_or(50, |x| if x > 100 { 100 } else { x });
 
-        rest::get_reaction_users(self.0,
+        http::get_reaction_users(self.0,
                                  message_id.into().0,
                                  &reaction_type.into(),
                                  limit,
@@ -340,12 +337,12 @@ impl ChannelId {
     ///
     /// # Errors
     ///
-    /// Returns a [`ClientError::MessageTooLong`] if the content of the message
+    /// Returns a [`ModelError::MessageTooLong`] if the content of the message
     /// is over the above limit, containing the number of unicode code points
     /// over the limit.
     ///
-    /// [`ChannelId`]: ../model/struct.ChannelId.html
-    /// [`ClientError::MessageTooLong`]: enum.ClientError.html#variant.MessageTooLong
+    /// [`ChannelId`]: struct.ChannelId.html
+    /// [`ModelError::MessageTooLong`]: enum.ModelError.html#variant.MessageTooLong
     #[inline]
     pub fn say(&self, content: &str) -> Result<Message> {
         self.send_message(|m| m.content(content))
@@ -382,11 +379,11 @@ impl ChannelId {
     /// # Errors
     ///
     /// If the content of the message is over the above limit, then a
-    /// [`ClientError::MessageTooLong`] will be returned, containing the number
+    /// [`ModelError::MessageTooLong`] will be returned, containing the number
     /// of unicode code points over the limit.
     ///
-    /// [`ClientError::MessageTooLong`]: ../client/enum.ClientError.html#variant.MessageTooLong
-    /// [`CreateMessage::content`]: ../utils/builder/struct.CreateMessage.html#method.content
+    /// [`ModelError::MessageTooLong`]: enum.ModelError.html#variant.MessageTooLong
+    /// [`CreateMessage::content`]: ../builder/struct.CreateMessage.html#method.content
     /// [`GuildChannel`]: struct.GuildChannel.html
     /// [Attach Files]: permissions/constant.ATTACH_FILES.html
     /// [Send Messages]: permissions/constant.SEND_MESSAGES.html
@@ -397,14 +394,14 @@ impl ChannelId {
         if let Some(content) = map.get("content") {
             if let Value::String(ref content) = *content {
                 if let Some(length_over) = Message::overflow_length(content) {
-                    return Err(Error::Client(ClientError::MessageTooLong(length_over)));
+                    return Err(Error::Model(ModelError::MessageTooLong(length_over)));
                 }
             }
         }
 
         let _ = map.remove("embed");
 
-        rest::send_file(self.0, file, filename, map)
+        http::send_file(self.0, file, filename, map)
     }
 
     /// Sends a message to the channel.
@@ -418,13 +415,13 @@ impl ChannelId {
     ///
     /// # Errors
     ///
-    /// Returns a [`ClientError::MessageTooLong`] if the content of the message
+    /// Returns a [`ModelError::MessageTooLong`] if the content of the message
     /// is over the above limit, containing the number of unicode code points
     /// over the limit.
     ///
     /// [`Channel`]: enum.Channel.html
-    /// [`ClientError::MessageTooLong`]: ../client/enum.ClientError.html#variant.MessageTooLong
-    /// [`CreateMessage`]: ../utils/builder/struct.CreateMessage.html
+    /// [`ModelError::MessageTooLong`]: enum.ModelError.html#variant.MessageTooLong
+    /// [`CreateMessage`]: ../builder/struct.CreateMessage.html
     /// [Send Messages]: permissions/constant.SEND_MESSAGES.html
     pub fn send_message<F>(&self, f: F) -> Result<Message>
         where F: FnOnce(CreateMessage) -> CreateMessage {
@@ -433,7 +430,7 @@ impl ChannelId {
         Message::check_content_length(&map)?;
         Message::check_embed_length(&map)?;
 
-        rest::send_message(self.0, &Value::Object(map))
+        http::send_message(self.0, &Value::Object(map))
     }
 
     /// Unpins a [`Message`] in the channel given by its Id.
@@ -444,7 +441,7 @@ impl ChannelId {
     /// [Manage Messages]: permissions/constant.MANAGE_MESSAGES.html
     #[inline]
     pub fn unpin<M: Into<MessageId>>(&self, message_id: M) -> Result<()> {
-        rest::unpin_message(self.0, message_id.into().0)
+        http::unpin_message(self.0, message_id.into().0)
     }
 
     /// Retrieves the channel's webhooks.
@@ -454,7 +451,7 @@ impl ChannelId {
     /// [Manage Webhooks]: permissions/constant.MANAGE_WEBHOOKS.html
     #[inline]
     pub fn webhooks(&self) -> Result<Vec<Webhook>> {
-        rest::get_channel_webhooks(self.0)
+        http::get_channel_webhooks(self.0)
     }
 
     /// Alias of [`invites`].