future.py

@attr.s
class TrioFuture:
    _result = attr.ib(default=None)
    _finished = attr.ib(default=attr.Factory(trio.Event))
    
    def set_result(self, result):
        assert not self._finished.is_set()
        self._result = result
        self._finished.set()
        
    async def get(self):
        await self._finished.wait()
        return self._result.unwrap()
      
    # Sugar
    def set_value(self, value):
        self.set_result(trio.hazmat.Value(value))
      
    # Sugar
    def set_exception(self, exc):
        self.set_result(trio.hazmat.Error(exc))