r3bl-ts-utils/src/lang-utils/expression-lang-utils.ts

The `r3bl-ts-utils` package is a set of useful TypeScript functions and classes that can be used in Node.js and browser environments. They are inspired by Kotlin stdlib, and Rust to write code as expressions rather than statements, colorized text, powerfu

/*
 * Copyright (c) 2022 R3BL LLC. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

import { Optional } from "./core"

/**
 * https://developer.mozilla.org/en-US/docs/Glossary/Truthy
 * @param ctxObject it can be null or undefined
 * @param receiverFn lambda that accepts `it`; only runs if `ctxObject` property is truthy
 * @return ctxObject the first argument
 */
export const _callIfTruthy = <T>(
  ctxObject: Optional<T>,
  receiverFn: TruthyReceiverFn<T>
): Optional<T> => {
  if (ctxObject) receiverFn(ctxObject)
  return ctxObject
}
export type TruthyReceiverFn<T> = (it: T) => void

export const _callIfTruthyWithReturn = <T, R>(
  ctxObject: Optional<T>,
  onTrue: TruthyReceiverWithReturnValueFn<T, R>,
  onFalse: SimpleReceiverWithReturnValueFn<R>
): R => {
  if (ctxObject) return onTrue(ctxObject)
  return onFalse()
}
export type TruthyReceiverWithReturnValueFn<T, R> = (it: T) => R

/**
 * https://developer.mozilla.org/en-US/docs/Glossary/Falsy
 * @param ctxObject it can be null or undefined
 * @param receiverFn lambda that only runs if `ctxObject` property is falsy
 */
export const _callIfFalsy = (ctxObject: unknown, receiverFn: FalsyReceiverFn) =>
  !ctxObject ? receiverFn() : undefined

export type FalsyReceiverFn = () => void

export const _repeat = (count: number, fun: () => void): void => {
  for (let i = 0; i < count; i++) fun()
}

export const _callIfTrue = (
  ctxObject: boolean,
  onTrueReceiverFn: SimpleReceiverFn,
  onFalseReceiverFn?: SimpleReceiverFn
): void => {
  if (ctxObject) onTrueReceiverFn()
  else onFalseReceiverFn ? onFalseReceiverFn() : undefined
}
export const _callIfFalse = (
  ctxObject: boolean,
  onFalseReceiverFn: SimpleReceiverFn,
  onTrueReceiverFn?: SimpleReceiverFn
): void => {
  if (!ctxObject) onFalseReceiverFn()
  else onTrueReceiverFn ? onTrueReceiverFn() : undefined
}
export type SimpleReceiverFn = () => void

export const _callIfTrueWithReturn = <T>(
  ctxObject: boolean,
  onTrueReceiverFn: SimpleReceiverWithReturnValueFn<T>,
  onFalseReceiverFn: SimpleReceiverWithReturnValueFn<T>
): T => {
  if (ctxObject) return onTrueReceiverFn()
  return onFalseReceiverFn()
}
export type SimpleReceiverWithReturnValueFn<T> = () => T