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@sandlada/result

promise-option

@sandlada/result/promise-option — eager operators on Promise<IOption<T>>.

Scope

Section titled “Scope”
  • Operates on: Promise<IOption<T>>; callbacks may be synchronous or asynchronous depending on the operator.
  • Execution model: eager — the chain starts on the call and the returned Promise is already in flight.
  • Not here: sync Option operators (option), lazy thunks (async-option), Result variants (promise-result).

API

Section titled “API”

Constructors (re-exported)

Section titled “Constructors (re-exported)”
Export Description Source
asyncOk / asyncErr Pre-resolved Result Promises from factories. ../factories/asyncOk.ts, ../factories/asyncErr.ts
ofSome / ofNone Sync Option constructors from option. ../option/ofSome.ts, ../option/ofNone.ts

Operators on Promise<IOption>

Section titled “Operators on Promise<IOption>”
Export Description Source
mapAsyncOption Transforms the Some value with an async callback. mapAsyncOption.ts
bindAsyncOption Async chain returning the next Option. bindAsyncOption.ts
orElseAsyncOption Async fallback on None. orElseAsyncOption.ts
matchAsyncOption Async terminal pattern match. matchAsyncOption.ts
mapOrAsyncOption / mapOrElseAsyncOption Map the Some value or fall back asynchronously. mapOrAsyncOption.ts, mapOrElseAsyncOption.ts
tapAsyncOption / tapErrAsyncOption Async side effects. tapAsyncOption.ts, tapErrAsyncOption.ts
unwrapOrAsyncOption / unwrapOrElseAsyncOption Extract the value or an async default. unwrapOrAsyncOption.ts, unwrapOrElseAsyncOption.ts
containsAsyncOption / existsAsyncOption / filterAsyncOption Async predicate queries. containsAsyncOption.ts, existsAsyncOption.ts, filterAsyncOption.ts
flattenAsyncOption Flattens Promise<IOption<IOption<T>>>. flattenAsyncOption.ts

Lift sync IOption → async

Section titled “Lift sync IOption → async”
Export Description Source
asyncMapOption Async map on a sync IOption. asyncMapOption.ts
asyncBindOption Async chain on a sync IOption. asyncBindOption.ts
asyncOrElseOption Async fallback on a sync IOption. asyncOrElseOption.ts
asyncMatchOption Async terminal match on a sync IOption. asyncMatchOption.ts
asyncTapOption Async side effect on a sync IOption. asyncTapOption.ts

Contract notes

Section titled “Contract notes”
  • A rejection of the outer Promise itself always stays a rejection; it is never converted into None.
  • Callback policy: operators on Promise<IOption> collapse a throwing callback or an async rejection into None / false / the default value; matchAsyncOption, mapOrElseAsyncOption and unwrapOrElseAsyncOption propagate instead. The lifting family (asyncMapOption, asyncBindOption, asyncTapOption, asyncOrElseOption) turns a synchronous throw into None but lets a rejected Promise propagate. See behavior-modes.md §4.6.
  • This layer has no unwrap / expect / orThrow; extraction goes through the unwrapOr* family.
  • There are no combination APIs here; combine Options with the sync option/all before lifting when needed.
  • Naming: the AsyncOption suffix marks operators that consume a Promise<IOption>; the async*Option prefix marks the lift family that consumes a synchronous IOption.

Design notes

Section titled “Design notes”
  • Eager and lazy async are separate modules. promise-option mirrors promise-result on the Option track, while async-option provides the lazy thunk counterpart.
Section titled “Related”