/**
 * Functions that does nothing (useful for default callbacks)
 */
export function nop(...args: any[]): any {
}

/**
 * Identity function (returns the sole argument untouched)
 */
export function identity<T>(input: T): T {
  return input;
}

/**
 * Partially apply fixed arguments to a function with named arguments
 */
export function partial<
  A extends object,
  PA extends Partial<A>,
  RA extends any[],
  R,
>(
  fixedargs: PA,
  func: (args: A, ...rest: RA) => R,
): (args: Omit<A, keyof PA>, ...rest: RA) => R {
  return (args: Omit<A, keyof PA>, ...rest: RA) =>
    func({ ...fixedargs, ...args } as any, ...rest);
}

/**
 * Pipe the result of a function as first parameter of another, to create a new function
 */
export function pipe<IN extends any[], INT, R>(
  f1: (...args: IN) => INT,
  f2: (value: INT) => R,
): (...args: IN) => R {
  return (...args: IN) => f2(f1(...args));
}