Event Loop & Dispatch

A bot framework provides a way to register handlers for events, then runs a loop dispatching events to handlers.

Async (Python's asyncio):

• Bot makes API calls (network I/O).
• Async lets handler await without blocking other handlers.
• Single event loop processes thousands of concurrent events.

Decorators:

• @bot.on('message') is syntactic sugar.
• Runtime: handlers list per event type.

Type-based routing:

• Each event has a type (message, reaction, join, leave, etc.).
• Multiple handlers per type allowed.

Filters:

• Run handler only if event matches criteria.
• E.g., only in specific channel, only from specific user.

Or:

Middleware:

• Chain of preprocessors.
• Auth check, logging, rate limit.

For our toy: simple decorator-based dispatch. No middleware in MVP.