rubico/dist/some.mjs

[a]synchronous functional programming

/**
 * rubico v2.6.2
 * https://github.com/a-synchronous/rubico
 * (c) 2019-2024 Richard Tong
 * rubico may be freely distributed under the MIT license.
 */

const isPromise = value => value != null && typeof value.then == 'function'

const __ = Symbol.for('placeholder')

// argument resolver for curry2
const curry2ResolveArg0 = (
  baseFunc, arg1,
) => function arg0Resolver(arg0) {
  return baseFunc(arg0, arg1)
}

// argument resolver for curry2
const curry2ResolveArg1 = (
  baseFunc, arg0,
) => function arg1Resolver(arg1) {
  return baseFunc(arg0, arg1)
}

const curry2 = function (baseFunc, arg0, arg1) {
  return arg0 == __
    ? curry2ResolveArg0(baseFunc, arg1)
    : curry2ResolveArg1(baseFunc, arg0)
}

const isArray = Array.isArray

const objectValues = Object.values

const SelfReferencingPromise = function (basePromise) {
  const promise = basePromise.then(res => [res, promise])
  return promise
}

const promiseRace = Promise.race.bind(Promise)

const asyncArraySome = async function (
  array, predicate, index, promisesInFlight,
) {
  const length = array.length

  while (++index < length) {
    const predication = predicate(array[index])
    if (isPromise(predication)) {
      promisesInFlight.add(SelfReferencingPromise(predication))
    } else if (predication) {
      return true
    }
  }
  while (promisesInFlight.size > 0) {
    const [predication, promise] = await promiseRace(promisesInFlight)
    promisesInFlight.delete(promise)
    if (predication) {
      return true
    }
  }
  return false
}

const arraySome = function (array, predicate) {
  const length = array.length
  let index = -1
  while (++index < length) {
    const predication = predicate(array[index])
    if (isPromise(predication)) {
      return asyncArraySome(
        array, predicate, index, new Set([SelfReferencingPromise(predication)]))
    }
    if (predication) {
      return true
    }
  }
  return false
}

const asyncIteratorSome = async function (
  iterator, predicate, promisesInFlight, maxConcurrency = 20,
) {
  let iteration = iterator.next()
  if (isPromise(iteration)) {
    iteration = await iteration
  }

  while (!iteration.done) {
    if (promisesInFlight.size >= maxConcurrency) {
      const [predication, promise] = await promiseRace(promisesInFlight)
      promisesInFlight.delete(promise)
      if (predication) {
        return true
      }
    }
    const predication = predicate(iteration.value)
    if (isPromise(predication)) {
      promisesInFlight.add(SelfReferencingPromise(predication))
    } else if (predication) {
      return true
    }
    iteration = iterator.next()
    if (isPromise(iteration)) {
      iteration = await iteration
    }
  }
  while (promisesInFlight.size > 0) {
    const [predication, promise] = await promiseRace(promisesInFlight)
    promisesInFlight.delete(promise)
    if (predication) {
      return true
    }
  }
  return false
}

const iteratorSome = function (iterator, predicate) {
  for (const item of iterator) {
    const predication = predicate(item)
    if (isPromise(predication)) {
      return asyncIteratorSome(
        iterator, predicate, new Set([SelfReferencingPromise(predication)]))
    }
    if (predication) {
      return true
    }
  }
  return false
}

const reducerAnySync = predicate => function anyReducer(result, item) {
  return result ? true : predicate(item)
}

const reducerSome = predicate => function anyReducer(result, item) {
  return result === true ? result
    : isPromise(result) ? result.then(curry2(reducerAnySync(predicate), __, item))
    : result ? true : predicate(item)
}

const symbolIterator = Symbol.iterator

const symbolAsyncIterator = Symbol.asyncIterator

// _some(collection Array|Iterable|AsyncIterable|{ reduce: function }|Object, predicate function) -> Promise|boolean
const _some = function (collection, predicate) {
  if (isArray(collection)) {
    return arraySome(collection, predicate)
  }
  if (collection == null) {
    return predicate(collection)
  }
  if (typeof collection[symbolIterator] == 'function') {
    return iteratorSome(collection[symbolIterator](), predicate)
  }
  if (typeof collection[symbolAsyncIterator] == 'function') {
    return asyncIteratorSome(
      collection[symbolAsyncIterator](), predicate, new Set()
    )
  }
  if (typeof collection.reduce == 'function') {
    return collection.reduce(reducerSome(predicate), false)
  }
  if (collection.constructor == Object) {
    return arraySome(objectValues(collection), predicate)
  }
  return predicate(collection)
}

const some = function (arg0, arg1) {
  if (typeof arg0 == 'function') {
    return curry2(_some, __, arg0)
  }
  return isPromise(arg0)
    ? arg0.then(curry2(_some, __, arg1))
    : _some(arg0, arg1)
}

export default some