recursive-free

Readme

Make your recursive-like functions leave stack overflow.

• Simulate function stack to void stack overflow in recursive-like functions.
• High performance implemented by JavaScript Map.

Install

npm install --save recursive-free

Usage

Write your recursive in function *. yield means call self.

recursiveFree has tow generic types. First for function paramater, also provide after yeild expression. Second for function return value, also recevied from yeild expression.

Just consider yield is a calling of the function self.

import recursiveFree from 'recursive-free'

const rec = recursiveFree<number, string>(function* (num) {
    if (num === 1) {
        return `,${num}`
    }
    return `${yield num - 1},${num}`
})

console.log(
    rec(5)
)

// ,1,2,3,4,5

Example

//Call 100000 times. It will throw stack overflow error in normal recursive functions.

import recursiveFree from 'recursive-free'

const rec = recursiveFree<number, void>(function* (num) {
    if (num === 1000000) {
        console.log('finish')
        return
    }
    yield num + 1
})
let t = performance.now()
rec(1)
console.log(`${performance.now() - t}ms`)

//finish
//500ms

//Fibonacci

import recursiveFree from 'recursive-free'

const rec = recursiveFree<number, number>(function* (n) {
    if (n < 2) {
        return n
    }
    return (yield n - 1) + (yield n - 2)
})

console.log([1, 2, 3, 4, 5, 6, 7, 8].map(ind => rec(ind)).join(','))
//1,1,2,3,5,8,13,21

//Output result of [1,2,3] X [1,2,3] X [1,2,3]

import recursiveFree from 'recursive-free'

const rec = recursiveFree<{
    num: number
    str: string
}, void>(function* (param) {
    const { str, num } = param
    if (num === 3) {
        console.log(str)
        return
    }
    for (let i of [1, 2, 3]) {
        yield {
            str: `${str},${i}`,
            num: num + 1
        }
    }
})
rec({
    num: 0,
    str: ''
})