stringless

Type-level Socket.IO protocol design for Rust: events as typed values.

One descriptor type per event, carrying direction, payload, and namespace marker.

No macros, no runtime registration. The wrong direction, payload or namespace fail to compile.

use stringless::*;

struct Conversation;
impl Protocol for Conversation {
    type Auth = ();
    const NAMESPACE: &'static str = "/conversation";
}

struct Command;
struct QueuedPayload;

impl Conversation {
    const COMMAND: ClientEvent<Self, Command> = ClientEvent::new("command");
    const QUEUED: ServerEvent<Self, QueuedPayload> = ServerEvent::new("queued");
}

// These fail to compile:
//   socket.emit(Conversation::COMMAND, &command);  // wrong direction
//   socket.emit(Conversation::QUEUED, &other);     // wrong payload
//   socket.emit(Other::QUEUED, &queued);           // wrong namespace

Companion to post.

The three compile-fail guarantees are tested in the crate docs (cargo test).