trampoline-js

trampoline-js

Transforms recursion ⟹ loop

Usage

Install from npm

npm install trampoline-js

let { trampoline, done, more } = require('trampoline-js')


const times = (() => {
  // optional accumulators & user input
  const _times = (acc, n, s) =>
    n <= 0
      // on done (base condition)
      ? done(acc)
      // continuation as thunks
      // takes continuation function and params
      : more(_times, `${acc}${s}`, n - 1, s)
  // build trampoline by passing recursive function and optional initial objects
  return trampoline(_times, '')
})()

times(5, '*')
// > '*****'

API

function trampoline(genFun, [args])

trampoline takes generate/recursive function and optional arguments (optional). it returns a function of form function ([arguments]) {}.

On invoking returned function, genFun will be called with args followed by caller supplied arguments.

genFun should return either done (a wrapper for base case) or more(a wrapper function for continuation function). Otherwise, 'Invalid continuation' Error will be thrown.

function more(fun, [args])

more should provide continuation function as first parameter and optional args.

function cont(fun, [args])

Alias for more.

function done(result)

done is a base case wrapper which takes terminal object and result will be returned as output.

License

This plugin is licensed under the MIT license.

Copyright (c) 2016 Prince John Wesley