Factory for multiple retries flow. similar to the simple retry, but this will allow to break down a "heavy" element which failed into multiple "thin" elements, that may succeed individually. Since it's easy to inflate elements in retry cycle, there's also a limit parameter, that will limit the amount of generated elements by the `retryWith` function, and will fail the stage if that limit is exceeded.

Passing `null` is valid, and will result in filtering out the failure quietly, without emitting a failed Result<T> element.

IMPORTANT CAVEAT: The given flow must not change the number of elements passing through it (i.e. it should output exactly one element for every received element). Ignoring this, will have an unpredicted result, and may result in a deadlock.

Declaration

public static IGraph<FlowShape<(TIn, TState), (Result<TOut>, TState)>, TMat> Concat<TIn, TState, TOut, TMat>(long limit, IGraph<FlowShape<(TIn, TState), (Result<TOut>, TState)>, TMat> flow, Func<TState, IEnumerable<(TIn, TState)>> retryWith)

Parameters

Type	Name	Description
long	limit	since every retry can generate more elements, the inner queue can get too big. if the limit is reached, the stage will fail.
IGraph<FlowShape<(TIn, TState), (Result<TOut>, TState)>, TMat>	flow	the flow to retry
Func<TState, IEnumerable<(TIn, TState)>>	retryWith	if output was failure, we can optionaly recover from it, and retry with a sequence of input and new state pairs we get from this function.

Returns

Type	Description
IGraph<FlowShape<(TIn, TState), (Result<TOut>, TState)>, TMat>

Type Parameters

Name	Description
TIn	input elements type
TState	state to create a new `(I,S)` to retry with
TOut	output elements type
TMat	materialized value type

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Create<TIn, TState, TOut, TMat>(IGraph<FlowShape<(TIn, TState), (Result<TOut>, TState)>, TMat>, Func<TState, Option<(TIn, TState)>>)

EXPERIMENTAL API

Retry flow factory. given a flow that produces Result<T>s, this wrapping flow may be used to try and pass failed elements through the flow again. More accurately, the given flow consumes a tuple of `input` and `state`, and produces a tuple of Result<T> of `output` and `state`. If the flow emits a failed element (i.e. IsSuccess is false), the retryWith function is fed with the `state` of the failed element, and may produce a new input-state tuple to pass through the original flow. The function may also yield `Option.None` instead of `(input, state)`, which means not to retry a failed element.

Declaration

public static IGraph<FlowShape<(TIn, TState), (Result<TOut>, TState)>, TMat> Create<TIn, TState, TOut, TMat>(IGraph<FlowShape<(TIn, TState), (Result<TOut>, TState)>, TMat> flow, Func<TState, Option<(TIn, TState)>> retryWith)

Parameters

Type	Name	Description
IGraph<FlowShape<(TIn, TState), (Result<TOut>, TState)>, TMat>	flow	the flow to retry
Func<TState, Option<(TIn, TState)>>	retryWith	if output was failure, we can optionaly recover from it, and retry with a new pair of input and new state we get from this function.

Returns

Type	Description
IGraph<FlowShape<(TIn, TState), (Result<TOut>, TState)>, TMat>

Type Parameters

Name	Description
TIn	input elements type
TState	state to create a new `(I,S)` to retry with
TOut	output elements type
TMat	materialized value type