runloop

The runloop module contains all functions and constants to use the Runloop for asynchronous IO programming.

To use the runloop module, add the following import statement to your project:

import runloop

All functions in the module should be called inside the runloop module as a prefix like so:

runloop.run(some_async_function())

The following constants are defined:

• WAITING = 0

• SUCCESS = 1

• TIMEOUT = 2

• CANCELLED = 3

Functions

run(*functions)	Start any number of parallel async functions.
sleep_ms(duration)	Pause the execution of the application for any amount of milliseconds.
until(function[, timeout])	Returns an awaitable that will return when the condition in the function or lambda passed is True or when it times out.
wait(unknown)	UNDOCUMENTED Behavior is not known; use with caution.

runloop.run(*functions)

Start any number of parallel async functions. This is the function you should use to create programs with a similar structure to Word Blocks.

Parameters:

functions (Awaitable) – A tuple of the functions to run

Return type:

None

runloop.sleep_ms(duration)

Pause the execution of the application for any amount of milliseconds.

from hub import light_matrix
import runloop

async def main():
    light_matrix.write("Hi!")
    # Wait for ten seconds
    await runloop.sleep_ms(10000)
    light_matrix.write("Are you still here?")

runloop.run(main())

Parameters:

duration (int) – The duration in milliseconds

Return type:

Awaitable

runloop.until(function, timeout=0)

Returns an awaitable that will return when the condition in the function or lambda passed is True or when it times out.

import color_sensor
import color
from hub import port
import runloop

def is_color_red():
    return color_sensor.color(port.A) is color.RED

async def main():
    # Wait until Color Sensor sees red
    await runloop.until(is_color_red)
    print("Red!")

runloop.run(main())

Parameters:

• function (Callable[[], bool]) – A callable with no parameters that returns either True or False. Callable is anything that can be called, so a def or a lambda

• timeout (int) – A timeout for the function in milliseconds. If the callable does not return True within the timeout, the until still resolves after the timeout. 0 means no timeout, in that case it will not resolve until the callable returns True.

Return type:

Awaitable

runloop.wait(unknown)

UNDOCUMENTED Behavior is not known; use with caution.

Parameters:

unknown (Iterator) – Meaning unknown

Return type:

Awaitable