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, 5 insertions, 5 deletions

diff --git a/src/model/utils.rs b/src/model/utils.rs
index 4d6b385..f88ecf5 100644
--- a/src/model/utils.rs
+++ b/src/model/utils.rs
@@ -9,7 +9,7 @@ use ::internal::prelude::*;
 #[cfg(feature="cache")]
 use super::permissions::Permissions;
 #[cfg(feature="cache")]
-use ::client::CACHE;
+use ::CACHE;
 
 pub fn deserialize_emojis<'de, D: Deserializer<'de>>(deserializer: D)
     -> StdResult<HashMap<EmojiId, Emoji>, D::Error> {
@@ -137,14 +137,14 @@ pub fn deserialize_voice_states<'de, D: Deserializer<'de>>(deserializer: D)
     Ok(voice_states)
 }
 
-#[cfg(feature="cache")]
+#[cfg(all(feature="cache", feature="model"))]
 pub fn user_has_perms(channel_id: ChannelId, mut permissions: Permissions) -> Result<bool> {
     let cache = CACHE.read().unwrap();
     let current_user = &cache.user;
 
     let channel = match cache.channel(channel_id) {
         Some(channel) => channel,
-        None => return Err(Error::Client(ClientError::ItemMissing)),
+        None => return Err(Error::Model(ModelError::ItemMissing)),
     };
 
     let guild_id = match channel {
@@ -159,13 +159,13 @@ pub fn user_has_perms(channel_id: ChannelId, mut permissions: Permissions) -> Re
             //
             // Since serenity can't _reasonably_ check and keep track of these,
             // just assume that all permissions are granted and return `true`.
-            return Ok(true); 
+            return Ok(true);
         },
     };
 
     let guild = match cache.guild(guild_id) {
         Some(guild) => guild,
-        None => return Err(Error::Client(ClientError::ItemMissing)),
+        None => return Err(Error::Model(ModelError::ItemMissing)),
     };
 
     let perms = guild.read().unwrap().permissions_for(channel_id, current_user.id);