higher-decorators v1.2.0

Higher Decorators

Library that offers a wide range of functional decorators for efficient and effective code development.

Installation

# npm
npm i higher-decorators

# yarn
yarn add higher-decorators

Usage

@cached

Uses a memoization mechanism for functions

Parameters

timeout?: number - lifetime of a stored value in milliseconds

Returns

The cached return value

Example

class Process {
    @cached()
    run(a: number, b: number) {
        // complex algorithm
        return a * b
    }
}

@repeat

Makes a function call repeat itself

Parameters

interval: number = 0 - interval between calls in milliseconds

times?: number - number of calls

Returns

cancel: Function - abolish the recurrence calls

pause: Function - pause the recurrence calls

resume: Function - resume the recurrence calls

Example

class Process {
    @repeat(10000, 20)
    run() {
        // computations
        console.log('Status')
    }
}

const process = new Process()
const { cancel, pause, resume } = process.run()
setTimeout(pause, 1000)
setTimeout(resume, 3000)
setTimeout(cancel, 6000)

@wrap

Uses a wrapper function in a convenience way

Parameters

wrapper: Wrapper - the wrapper function

Returns

The return value

Example

const errorHandler = (fn: Function, ...args: any) => {
  try {
      fn(...args)
  } catch(err) {
    console.log('Catched', err);
  }
}

class Process {
  @wrap(errorHandler)
  run(value: string) {
      throw new Error(value)
  }
}

@time

Logs the time used by a function

Parameters

No parameters

Returns

The return value

Example

class Process {
  @time()
  run() {
    // complex algorithm
  }
}

@delay

Postpones the function call

Parameters

timeout: number - delay time in milliseconds

Returns

No return value

Example

class Process {
  @delay(500)
  run() {
    console.log('Run after 500 milliseconds')
  }
}

@promisifyDelay

Postpones the function call returning a promise object

Parameters

timeout: number - delay time in milliseconds

Returns

A promise object for delay

class Process {
  @promisifyDelay(500)
  run() {
    console.log('Run after 500 milliseconds')
  }
}

const process = new Process()
process.run().then(() => {
    console.log('The End')
})