ShortCircuit

Executes a junction that can return early from the train. If the junction succeeds and returns a value of type TReturn, that value is captured as the short-circuit result — when Resolve is called, it returns this value instead of looking in Memory.

If the junction fails (returns Left), the failure is ignored — no exception is set, the train continues normally.

> Important: Subsequent Chain calls after a successful ShortCircuit still execute. The short-circuit value only affects Resolve() — it returns the captured value instead of doing a Memory lookup. If you need to skip remaining junctions entirely, combine ShortCircuit with a conditional pattern or use the railway error path.

ShortCircuit<TJunction>()

Creates and executes a junction with short-circuit behavior.

public Monad<TInput, TReturn> ShortCircuit<TJunction>() where TJunction : class

ShortCircuit<TJunction>(TJunction junctionInstance)

Executes a pre-created junction with short-circuit behavior.

public Monad<TInput, TReturn> ShortCircuit<TJunction>(TJunction junctionInstance) where TJunction : class

Example

protected override async Task<Either<Exception, OrderResult>> RunInternal(OrderInput input)
{
    return Activate(input)
        .ShortCircuit<CheckCache>()       // If cache has result, capture it for Resolve
        .Chain<ValidateOrder>()           // Still executes even on cache hit
        .Chain<ProcessPayment>()          // Still executes even on cache hit
        .Resolve();                       // Returns cached result OR processed result
}

Behavior

1. Creates the junction instance and extracts input from Memory.
2. Executes the junction.
3. If the junction succeeds and returns a value of type TReturn:
   • The value is stored as ShortCircuitValue.
   • Resolve() will return this value, bypassing Memory lookup.
4. If the junction fails (returns Left): the failure is ignored — no exception is set, the train continues normally.

Remarks

• The key difference from Chain: failures do not stop the train. A failing short-circuit junction is silently ignored.
• If the junction output type matches the train's TReturn, the value becomes the short-circuit result for Resolve().
• This is useful for cache checks, optional enrichment junctions, and conditional early returns.