adapters

@sandlada/result/adapters — bridges between plain functions / values and the Result railway.

Scope

Operates on: the boundary between single-track values or plain functions and two-track Results / Options.
Execution model: synchronous, except switchFnAsync / teeAsync, which await a Promise-returning callback.
Not here: Result operators (operators), Option operators (option).

API

Function shape

Export	Description	Source
`switchFn`	Wraps a plain function into a function returning `IResultOfT`; a throw is captured as `Err`.	switchFn.ts
`switchFnAsync`	Wraps a Promise-returning plain function into a function returning `Promise<IResultOfT>`.	switchFnAsync.ts
`liftMap`	Semantic alias of `operators/map` for lifting a plain function onto the success track.	liftMap.ts
`tee`	Single-track side effect: runs the callback and returns the input value unchanged.	tee.ts
`teeAsync`	Async single-track side effect: awaits the callback and returns the input value unchanged.	teeAsync.ts

Result ↔ Option

Export	Description	Source
`toOption`	`Ok(value)` becomes `Some(value)`; `Err` becomes `None`, discarding the error.	toOption.ts
`fromOption`	`Some(value)` becomes `Ok(value)`; `None` becomes `Err(error)`.	fromOption.ts

Contract notes

switchFn / switchFnAsync capture to values, including a second collapse when errorFn itself throws; liftMap delegates to operators/map, so it captures as well.
tee / teeAsync propagate directly — there is no failure state to convert.
toOption / fromOption never throw; fromOption needs an error value (or factory) for the None branch.
Throw policy: behavior-modes.md §4.4.

operators — the operators these adapters feed into.
option — Option-side operators, including okOr / transpose bridges.
primitives — lift, the dual-state alternative to switchFn.