Recursive class function

Question

I have code like this with two different classes in two different files. I want to call a class function from another just like in a recursive manner. Can I achieve this in JavaScript?

// lexer/index.js

const Quote = require(./tokenizer/quote.js)
module.exports = class Lexer {

  constructor(args) {
    // some get set method callings
  }
  
  run () {
    return Quote.tokenize(args)
  }
}

// lexer/tokenizer/quote

const Lexer = require('../index')
module.exports = class Quote {
  // no constructor
  // but there could be 

  static tokenize(args) {
    // some calculation for body
    // again call the lexer run
    const quoteLexer = new Lexer(body)
    return quoteLexer.run()
  }
}

// index

const Lexer = require("./lexer")
const l = new Lexer(someContent)
console.log(l.run())

currently, I'm getting the following error while executing this.

> node index.js

/home/kiran/dev/markdown-parser/lib/lexer/tokenizer/quote.js:57
    const quoteLexer = new Lexer(body)
                       ^

TypeError: Lexer is not a constructor
    at Function.tokenize (/home/kiran/dev/markdown-parser/lib/lexer/tokenizer/quote.js:57:24)

Code can be found at https://github.com/kiranparajuli589/markdown-parser/pull/17; To reproduce: just do npm install && npm run convert

I would suggest defining the class, then doing `module.exports = ClassName;` rather than trying to inline the class definition. See the answers to [How to properly export an ES6 class in Node 4?](https://stackoverflow.com/q/32657516/215552) and their comments. — Heretic Monkey, Jul 24 '22 at 13:47
the same error persists even if I use the suggested export pattern. :( — Kiran Parajuli, Jul 24 '22 at 13:55
To be fair, you don't have a `constructor` defined on the `Lexer` class... Maybe try adding `constructor() {}` to `Lexer`? It shouldn't be required, but I don't use CommonJS modules... — Heretic Monkey, Jul 24 '22 at 13:58
I have the constructor in the actual code. Just not in the question. I'll quickly add it in the question too. — Kiran Parajuli, Jul 24 '22 at 13:59
Does this question help? https://stackoverflow.com/questions/10107198/ — Jaxon Crosmas, Jul 24 '22 at 14:00
I think the problem is the "infinite require loop" you have, where `Lexer` requires `Quote`, which requires `Lexer`. I'm a little surprised there isn't a different error associated with that. — Heretic Monkey, Jul 24 '22 at 14:07
the question is slightly different. I'm trying the create a new obj from the class fn. — Kiran Parajuli, Jul 24 '22 at 14:07
@HereticMonkey, I I thought about your comment and now I've refactored the whole code to use `type: module` and substituted the `require` with `import`. It worked. — Kiran Parajuli, Jul 24 '22 at 15:20

Kiran Parajuli · Accepted Answer · 2022-08-09T18:38:56.857

0

Using a code like this solved the problem.

// lexer/index.js
import Quote from "./tokenizer/quote.js"

export default class Lexer{
  run() {
    Quote.tokenize(args)
  }
}

// lexer/tokenizer/quote.js
import Lexer from "../index.js"

export default class Quote {
  static tokenize() {
    const l = new Lexer(args)
    console.log(l.run())
  }
}

edited Aug 09 '22 at 18:38

answered Jul 24 '22 at 15:24

Kiran Parajuli

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Recursive class function

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