rubico/dist/not.es.js

[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 isArray = Array.isArray

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

const areAnyValuesPromises = function (values) {
  if (isArray(values)) {
    const length = values.length
    let index = -1
    while (++index < length) {
      const value = values[index]
      if (isPromise(value)) {
        return true
      }
    }
    return false
  }

  for (const key in values) {
    const value = values[key]
    if (isPromise(value)) {
      return true
    }
  }
  return false
}

const promiseAll = Promise.all.bind(Promise)

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)
}

// argument resolver for curryArgs2
const curryArgs2ResolveArgs0 = (
  baseFunc, arg1, arg2,
) => function args0Resolver(...args) {
  return baseFunc(args, arg1)
}

// argument resolver for curryArgs2
const curryArgs2ResolveArgs1 = (
  baseFunc, arg0, arg2,
) => function arg1Resolver(...args) {
  return baseFunc(arg0, args)
}

const curryArgs2 = function (baseFunc, arg0, arg1) {
  if (arg0 == __) {
    return curryArgs2ResolveArgs0(baseFunc, arg1)
  }
  return curryArgs2ResolveArgs1(baseFunc, arg0)
}

// negate(value boolean) -> inverse boolean
const negate = value => !value

// _not(args Array, predicate function)
const _not = function (args, predicate) {
  const boolean = predicate(...args)
  return isPromise(boolean) ? boolean.then(negate) : !boolean
}

const not = function (...args) {
  const predicateOrValue = args.pop()
  if (typeof predicateOrValue == 'function') {
    if (args.length == 0) {
      return curryArgs2(_not, __, predicateOrValue)
    }
    if (areAnyValuesPromises(args)) {
      return promiseAll(args).then(curry2(_not, __, predicateOrValue))
    }
    return _not(args, predicateOrValue)
  }
  return !predicateOrValue
}

export default not