zork/zork1.js

const VM = require('./lib/vm')
const fs = require('fs')
const data = fs.readFileSync('./games/ZORK1.DAT')
const saveFile = './zork1.sav'

const main = async () => {
    let state
    if (fs.existsSync(saveFile)) {
        state = JSON.parse(fs.readFileSync(saveFile, 'utf8'))
    } else {
        state = await VM.play(data)
    }
    while (state) {
        fs.writeFileSync(saveFile, JSON.stringify(state), 'utf8')
        if (typeof state.output === 'string') process.stdout.write(state.output)
        const text = (await new Promise(resolve => process.stdin.once('data', resolve))).toString()
        state = await VM.play(data, state.save, text.toString().trim())
    }
}

main().catch(console.error)