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https://github.com/firestar5683/StarPilot.git
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firestar5683
52 lines
1.5 KiB
Python
52 lines
1.5 KiB
Python
from typing import Callable, Optional, TypeVar, cast
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from reactivex import Observable, abc
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from reactivex.internal.exceptions import ArgumentOutOfRangeException
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_T = TypeVar("_T")
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def element_at_or_default_(
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index: int, has_default: bool = False, default_value: Optional[_T] = None
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) -> Callable[[Observable[_T]], Observable[_T]]:
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if index < 0:
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raise ArgumentOutOfRangeException()
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def element_at_or_default(source: Observable[_T]) -> Observable[_T]:
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def subscribe(
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observer: abc.ObserverBase[_T],
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scheduler: Optional[abc.SchedulerBase] = None,
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) -> abc.DisposableBase:
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index_ = index
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def on_next(x: _T) -> None:
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nonlocal index_
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found = False
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with source.lock:
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if index_:
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index_ -= 1
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else:
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found = True
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if found:
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observer.on_next(x)
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observer.on_completed()
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def on_completed():
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if not has_default:
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observer.on_error(ArgumentOutOfRangeException())
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else:
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observer.on_next(cast(_T, default_value))
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observer.on_completed()
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return source.subscribe(
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on_next, observer.on_error, on_completed, scheduler=scheduler
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)
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return Observable(subscribe)
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return element_at_or_default
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__all__ = ["element_at_or_default_"]
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