text: // REPL tool
  'use strict'
  import log from 'loglevel'
  import PromptSync from 'prompt-sync'
  
  import { FizzBuzzScheme as FBS } from '../src/index.js'
  
  log.setLevel('info')
  
  const promptSync = PromptSync({ sigint: true })
  
  let loop = true
  let fbs = new FBS()
  while (loop) {
    const exp = promptSync('fbs> ')
    if (exp === '') {
      // do nothing
    } else if (exp === 'clear') {
      fbs = new FBS()
    } else if (exp === 'd') {
      fbs.enableDebugMode()
      // fbs.eval('(define fib (lambda (n) (if (< n 2) n (+ (fib (- n 2)) (fib (- n 1))))))')
    } else if (exp === 'q') {
      console.log('bye.')
      loop = false
    } else {
      try {
        const res = fbs.eval(exp)
        console.log(res.toString())
      } catch (e) {
        console.log(e)
      }
    }
  }
  