https://github.com/jintwo/afsm

Simple asyncio FSM
https://github.com/jintwo/afsm

asyncio-fsm finite-state-machine python

Last synced: 4 days ago
JSON representation

Simple asyncio FSM

• Host: GitHub
• URL: https://github.com/jintwo/afsm
• Owner: jintwo
• License: mit
• Created: 2020-08-20T23:30:11.000Z (over 4 years ago)
• Default Branch: master
• Last Pushed: 2020-08-20T23:30:31.000Z (over 4 years ago)
• Last Synced: 2024-12-16T01:12:21.077Z (about 2 months ago)
• Topics: asyncio-fsm, finite-state-machine, python
• Language: Python
• Homepage:
• Size: 2.93 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# Simple asyncio FSM

## Usage

```python

from enum import Enum

import afsm

class CoffeeMakerStates(Enum):

    EMPTY = 'empty'

    HAS_WATER = 'has_water'

    HAS_BEANS = 'has_beans'

    ON = 'on'

    OFF = 'off'

    READY = 'ready'

class AddWater(afsm.Transition):

    async def post(self, prev_state, next_state, context, args):

        return dict(context, water=True)

class AddBeans(afsm.Transition):

    async def post(self, prev_state, next_state, context, args):

        return dict(context, beans=True)

class Trigger(afsm.Transition):

    async def pre(self, current_state, context, args):

        # we can't turn on coffeemaker without water and beans

        if 'water' in context and 'beans' in context:

            return (True, context)

        if current_state == CoffeeMakerStates.EMPTY:

            return (False, context)

        return (False, context)

class CoffeeMaker(afsm.FSM):

    add_water = AddWater({CoffeeMakerStates.EMPTY: CoffeeMakerStates.HAS_WATER,

                          CoffeeMakerStates.HAS_BEANS: CoffeeMakerStates.READY})

    add_beans = AddBeans({CoffeeMakerStates.EMPTY: CoffeeMakerStates.HAS_BEANS,

                          CoffeeMakerStates.HAS_WATER: CoffeeMakerStates.READY})

    trigger = Trigger({

        CoffeeMakerStates.OFF: CoffeeMakerStates.EMPTY,

        CoffeeMakerStates.READY: CoffeeMakerStates.ON,

        CoffeeMakerStates.ON: CoffeeMakerStates.OFF})

    def __init__(self):

        super().__init__(get_initial_state=lambda: CoffeeMakerStates.EMPTY,

                         get_initial_context=dict)

async def main()

    cm = CoffeeMaker()

    state, _ = await cm.trigger()

    assert state == CoffeeMakerStates.EMPTY

    state, context = await cm.add_beans()

    assert state == CoffeeMakerStates.HAS_BEANS and 'beans' in context

    # try again

    state, context = await cm.trigger()

    assert state == CoffeeMakerStates.HAS_BEANS and 'beans' in context

    state, context = await cm.add_water()

    assert state == CoffeeMakerStates.READY and 'water' in context

    # and again

    state, context = await cm.trigger()

    assert state == CoffeeMakerStates.ON and 'beans' in context and 'water' in context

asyncio.run(main())

```