Add CommandExt trait

euphoxide-bot/examples/examplebot.rs

@@ -3,10 +3,8 @@ use std::time::Duration;
 use async_trait::async_trait;
 use euphoxide::api::Message;
 use euphoxide_bot::{
-    bang::{General, Specific},
-    basic::Described,
     botrulez::{FullHelp, Ping, ShortHelp},
-    Command, Commands, Context, Info, Propagate,
+    Command, CommandExt, Commands, Context, Info, Propagate,
 };
 use euphoxide_client::MultiClient;
 use log::error;
@@ -44,18 +42,21 @@ impl Command for Pyramid {
 async fn main() {
     let (event_tx, mut event_rx) = mpsc::channel(10);
 
-    let commands = Commands::new()
-        .then(Described::hidden(General::new("ping", Ping::default())))
-        .then(Described::hidden(Specific::new("ping", Ping::default())))
-        .then(Described::hidden(General::new(
-            "help",
-            ShortHelp::new("/me demonstrates how to use euphoxide"),
-        )))
-        .then(Described::hidden(Specific::new(
-            "help",
-            FullHelp::new().with_after("Created using euphoxide."),
-        )))
-        .then(General::new("pyramid", Pyramid))
+    let commands = Commands::<euphoxide::Error>::new()
+        .then(Ping::default().general("ping").hidden())
+        .then(Ping::default().specific("ping").hidden())
+        .then(
+            ShortHelp::new("/me demonstrates how to use euphoxide")
+                .general("help")
+                .hidden(),
+        )
+        .then(
+            FullHelp::new()
+                .with_after("Created using euphoxide.")
+                .specific("help")
+                .hidden(),
+        )
+        .then(Pyramid.general("pyramid"))
         .build();
 
     let clients = MultiClient::new(event_tx);

euphoxide-bot/src/command.rs

@@ -7,6 +7,8 @@ pub mod clap;
 use std::{future::Future, sync::Arc};
 
 use async_trait::async_trait;
+use bang::{General, Global, Specific};
+use basic::{Described, Prefixed};
 use euphoxide::{
     api::{self, Data, Message, MessageId, SendEvent, SendReply},
     client::{
@@ -118,6 +120,39 @@ pub trait Command<E = euphoxide::Error> {
     async fn execute(&self, arg: &str, msg: &Message, ctx: &Context<E>) -> Result<Propagate, E>;
 }
 
+pub trait CommandExt: Sized {
+    fn described(self) -> Described<Self> {
+        Described::new(self)
+    }
+
+    fn hidden(self) -> Described<Self> {
+        Described::hidden(self)
+    }
+
+    fn prefixed(self, prefix: impl ToString) -> Prefixed<Self> {
+        Prefixed::new(prefix, self)
+    }
+
+    fn global(self, name: impl ToString) -> Global<Self> {
+        Global::new(name, self)
+    }
+
+    fn general(self, name: impl ToString) -> General<Self> {
+        General::new(name, self)
+    }
+
+    fn specific(self, name: impl ToString) -> Specific<Self> {
+        Specific::new(name, self)
+    }
+}
+
+// Sadly this doesn't work: `impl<E, C: Command<E>> CommandExt for C {}`
+// It leaves E unconstrained. Instead, we just implement CommandExt for all
+// types. This is fine since it'll crash and burn once we try to use the created
+// commands as actual commands. It also follows the spirit of adding trait
+// constraints only where they are necessary.
+impl<C> CommandExt for C {}
+
 pub struct Commands<E = euphoxide::Error> {
     commands: Vec<Box<dyn Command<E> + Sync + Send>>,
 }