Move the builders to the utils

The builders aren't a large enough portion of the library to deserve
their own root-level module, so move them to the `utils` module.

Additionally, split them into separate files, as the library will be
receiving more builders and the single-file pattern was getting rather
large.

1 files changed, 104 insertions, 0 deletions

diff --git a/src/utils/builder/edit_role.rs b/src/utils/builder/edit_role.rs
new file mode 100644
index 0000000..f4fa7ef
--- /dev/null
+++ b/src/utils/builder/edit_role.rs
@@ -0,0 +1,104 @@
+use serde_json::builder::ObjectBuilder;
+use std::default::Default;
+use ::model::{Permissions, Role, permissions};
+
+/// A builer to create or edit a [`Role`] for use via a number of model and
+/// context methods.
+///
+/// These are:
+///
+/// - [`Context::create_role`]
+/// - [`Context::edit_role`]
+/// - [`LiveGuild::create_role`]
+/// - [`Role::edit`]
+///
+/// Defaults are provided for each parameter on role creation.
+///
+/// # Examples
+///
+/// Create a hoisted, mentionable role named "a test role":
+///
+/// ```rust,ignore
+/// // assuming you are in a `context` and a `guild_id` has been bound
+/// let role = context.create_role(guild_id, |r| r
+///     .hoist(true)
+///     .mentionable(true)
+///     .name("a test role"));
+/// ```
+///
+/// [`Context::create_role`]: ../client/struct.Context.html#method.create_role
+/// [`Context::edit_role`]: ../client/struct.Context.html#method.edit_role
+/// [`LiveGuild::create_role`]: ../model/struct.LiveGuild.html#method.create_role
+/// [`Role`]: ../model/struct.Role.html
+/// [`Role::edit`]: ../model/struct.Role.html#method.edit
+pub struct EditRole(pub ObjectBuilder);
+
+impl EditRole {
+    /// Creates a new builder with the values of the given [`Role`].
+    pub fn new(role: &Role) -> Self {
+        EditRole(ObjectBuilder::new()
+            .insert("color", role.colour)
+            .insert("hoist", role.hoist)
+            .insert("managed", role.managed)
+            .insert("mentionable", role.mentionable)
+            .insert("name", &role.name)
+            .insert("permissions", role.permissions.bits())
+            .insert("position", role.position))
+    }
+
+    /// Sets the colour of the role.
+    pub fn colour(self, colour: u64) -> Self {
+        EditRole(self.0.insert("color", colour))
+    }
+
+    /// Whether or not to hoist the role above lower-positioned role in the user
+    /// list.
+    pub fn hoist(self, hoist: bool) -> Self {
+        EditRole(self.0.insert("hoist", hoist))
+    }
+
+    /// Whether or not to make the role mentionable, notifying its users.
+    pub fn mentionable(self, mentionable: bool) -> Self {
+        EditRole(self.0.insert("mentionable", mentionable))
+    }
+
+    /// The name of the role to set.
+    pub fn name(self, name: &str) -> Self {
+        EditRole(self.0.insert("name", name))
+    }
+
+    /// The set of permissions to assign the role.
+    pub fn permissions(self, permissions: Permissions) -> Self {
+        EditRole(self.0.insert("permissions", permissions.bits()))
+    }
+
+    /// The position to assign the role in the role list. This correlates to the
+    /// role's position in the user list.
+    pub fn position(self, position: u8) -> Self {
+        EditRole(self.0.insert("position", position))
+    }
+}
+
+impl Default for EditRole {
+    /// Creates a builder with default parameters.
+    ///
+    /// The defaults are:
+    ///
+    /// - **color**: 10070709
+    /// - **hoist**: false
+    /// - **mentionable**: false
+    /// - **name**: new role
+    /// - **permissions**: the [general permissions set]
+    /// - **position**: 1
+    ///
+    /// [general permissions set]: ../model/permissions/fn.general.html
+    fn default() -> EditRole {
+        EditRole(ObjectBuilder::new()
+            .insert("color", 10070709)
+            .insert("hoist", false)
+            .insert("mentionable", false)
+            .insert("name", String::from("new role"))
+            .insert("permissions", permissions::general().bits())
+            .insert("position", 1))
+    }
+}