Similar to AggregateTOut1, TOut2, TMat(SourceTOut1, TMat, TOut2, FuncTOut2, TOut1, TOut2) but uses first element as zero element. Applies the given function reduce towards its current and next value, yielding the next current value. If the stream is empty (i.e. completes before signaling any elements), the sum stage will fail its downstream with a NoSuchElementException, which is semantically in-line with that standard library collections do in such situations.

Emits when upstream completes

Backpressures when downstream backpressures

Completes when upstream completes

Cancels when downstream cancels

public static Source<TOut, TMat> Sum<TOut, TMat>(
	this Source<TOut, TMat> flow,
	Func<TOut, TOut, TOut> reduce
)

[<ExtensionAttribute>]
static member Sum : 
        flow : Source<'TOut, 'TMat> * 
        reduce : Func<'TOut, 'TOut, 'TOut> -> Source<'TOut, 'TMat>