kotlin-scope-functions-js/index.js

A JavaScript library implementing Kotlin-like scope functions: let and also

// scope-functions.js

// 辅助函数：检查是否是基本类型的包装对象
function isPrimitiveWrapper(value) {
  return value instanceof String ||
         value instanceof Number ||
         value instanceof Boolean ||
         value instanceof BigInt ||
         value instanceof Symbol;
}

/**
 * 类似 Kotlin 的 let 函数
 * @param {Function} block - 接收调用对象作为参数的函数
 * @returns {*} block 函数的返回值
 */
Object.defineProperty(Object.prototype, 'let', {
  value: function(block) {
    const self = isPrimitiveWrapper(this) ? this.valueOf() : this;
    return block(self);
  },
  enumerable: false,
  writable: true,
  configurable: true
});

/**
 * 类似 Kotlin 的 also 函数
 * @param {Function} block - 接收调用对象作为参数的函数
 * @returns {Object} 调用对象本身
 */
Object.defineProperty(Object.prototype, 'also', {
  value: function(block) {
    const self = isPrimitiveWrapper(this) ? this.valueOf() : this;
    block(self);
    return self;
  },
  enumerable: false,
  writable: true,
  configurable: true
});

// 实现 takeIf 函数
Object.defineProperty(Object.prototype, 'takeIf', {
  value: function(predicate) {
    const self = isPrimitiveWrapper(this) ? this.valueOf() : this;
    return predicate(self) ? self : null;
  },
  enumerable: false,
  writable: true,
  configurable: true
});

// 实现 takeUnless 函数
Object.defineProperty(Object.prototype, 'takeUnless', {
  value: function(predicate) {
    const self = isPrimitiveWrapper(this) ? this.valueOf() : this;
    return !predicate(self) ? self : null;
  },
  enumerable: false,
  writable: true,
  configurable: true
});