40 lines
1.0 KiB
GDScript
40 lines
1.0 KiB
GDScript
static func scan_(
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accumulator : Callable,
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seed_ = GDRx.util.GetNotSet()
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) -> Callable:
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var has_seed = !is_instance_of(seed_, GDRx.util.NotSet)
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var scan = func(source : Observable) -> Observable:
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# """Partially applied scan operator.
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#
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# Applies an accumulator function over an observable sequence and
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# returns each intermediate result.
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#
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# Examples:
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# >>> var scanned = scan.call(source)
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#
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# Args:
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# source: The observable source to scan.
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#
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# Returns:
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# An observable sequence containing the accumulated values.
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# """
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var factory = func(_scheduler : SchedulerBase) -> Observable:
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var has_accumulation = RefValue.Set(false)
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var accumulation = RefValue.Null()
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var projection = func(x):
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if has_accumulation.v:
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accumulation.v = accumulator.call(accumulation.v, x)
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else:
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accumulation.v = accumulator.call(seed_, x) if has_seed else x
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has_accumulation.v = true
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return accumulation.v
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return source.pipe1(GDRx.op.map(projection))
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return GDRx.obs.defer(factory)
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return scan
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