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Function: uniqueByAsync()

Returns an async iterable containing the values of asyncIterable in iteration order, except values for which fn returns a value awaitable to the same value are deduplicated.

When values are deduplicated, the value earlier in iteration order wins.

Example​

import { asAsync, pipe, reduceAsync, toArray, uniqueByAsync } from 'lfi'

const API_URL = `https://api.dictionaryapi.dev/api/v2/entries/en`

console.log(
  await pipe(
    asAsync([`sloth`, `lazy`, `sleep`]),
    uniqueByAsync(async word => {
      const response = await fetch(`${API_URL}/${word}`)
      const [{ meanings }] = await response.json()
      return meanings[0].partOfSpeech
    }),
    reduceAsync(toArray()),
  ),
)
//=> [ 'sloth', 'sleep' ]
Playground

Since​

v0.0.2

Call Signature​

uniqueByAsync<Value>(fn): (asyncIterable) => AsyncIterable<Value, any, any>

Type Parameters​

• Value

Parameters​

fn​

(value) => unknown

Returns​

Function

Parameters​

asyncIterable​

AsyncIterable<Value, any, any>

Returns​

AsyncIterable<Value, any, any>

Defined in​

filters.d.ts:474

Call Signature​

uniqueByAsync<Value>(fn, asyncIterable): AsyncIterable<Value, any, any>

Type Parameters​

• Value

Parameters​

fn​

(value) => unknown

asyncIterable​

AsyncIterable<Value, any, any>

Returns​

AsyncIterable<Value, any, any>

Defined in​

filters.d.ts:477