Variable: findLastConcur

const findLastConcur: FindConcur

Defined in: filters.d.ts:898

Returns a concur iterable containing the last value of concurIterable for which fn returns a value awaitable to a truthy value. Otherwise, returns an empty concur iterable.

If a non-empty concur iterable is returned, then the returned concur iterable does not reject, even if the input concurIterable does and even if the found value was emitted after an erroring value.

If an empty concur iterable is returned, then it will reject if the input concurIterable does.

Like Array.prototype.findLast, but for concur iterables. The error semantics are similar to Promise.any.

WARNING: This function always waits for concurIterable to finish iterating because that's the only way to ensure the found value is the last one.

Example

import { asConcur, findLastConcur, orConcur, pipe } from 'lfi'

const API_URL = `https://api.dictionaryapi.dev/api/v2/entries/en`
const getPartsOfSpeech = async word => {
  const response = await fetch(`${API_URL}/${word}`)
  const [{ meanings }] = await response.json()
  return meanings.map(meaning => meaning.partOfSpeech)
}

console.log(
  await pipe(
    asConcur([`sloth`, `lazy`, `sleep`]),
    findLastConcur(async word => (await getPartsOfSpeech(word)).includes(`verb`)),
    orConcur(() => `not found!`),
  ),
)
// NOTE: This word may change between runs
//=> sleep

console.log(
  await pipe(
    asConcur([`sloth`, `lazy`, `sleep`]),
    findLastConcur(async word => (await getPartsOfSpeech(word)).includes(`adverb`)),
    orConcur(() => `not found!`),
  ),
)
//=> not found!

Playground

Since

v0.0.2