game-coro 0.0.1

Coroutine runner for games

game_coro

Coroutines for games. Write logic as a python generator, then tick it every frame. Use yield to pause till the next frame, or use helpers to pause a given number of frames or seconds.

This library is currently experimental: no tests, few docs. For usage, check out the example: example/example.py

Run the example by cloning this repository, then:

python -m example.example

Design, Behavior

Coroutines should not expect raised exceptions to be swallowed.
Just like any other call, exceptions will crash the game.

Coroutines can wrap themselves in try-finally to implement cleanup logic.

Coroutines should use yield from to delegate to another generator function.

When a coroutine is stopped, generator .close() is called. This follows standard python rules, where a GeneratorExit is raised within the generator.

When coroutine A yields to coroutine B, the return value of B is passed to A. Any raised exception from B is raised in A. Just like a normal call stack.

When implementing a state machine, back-and-forth yield from other_state() will eventually fill up the call stack, crashing the game. Instead, return other_state(). return will close the current generator function, and the coroutine manager will detect that you've returned another generator and start iterating it. This only works when returning from your top-level generator. If in a nested generator call, use trampoline(): yield from trampoline(other_state())

Tips and Tricks

return (yield from self.other())

Allows self.other() to return a value, which will be returned through Can trampoline from it.