Function deriveNamed

deriveNamed<K extends string, C extends object, T>(
    key: K,
    fn: (ctx: C) => T,
): <I extends object, E, M extends RailwayMode>(
    workflow: Railway<I, E, M>,
) => Railway<I & Record<K, T>, E, M>
Reusable wrapper around Railway.derive — pure sync derivation.
Type Parameters
- K extends string
- C extends object
- T
Parameters
- key: K
- fn: (ctx: C) => T
Returns <I extends object, E, M extends RailwayMode>(
workflow: Railway<I, E, M>,
) => Railway<I & Record<K, T>, E, M>
- Defined in packages/result/src/railway.ts:454