程序概述
我一直在写一个程序来帮助用户记住圆周率的数字。
遇到的问题
该程序包括以下提示，由查询者npm提供。
>>>>>>>>>> PI GAME <<<<<<<<<<
? Select your mode: …
❯ PRACTICE MODE
SHOW PI DIGITS
HIGH SCORES
我想在模式选择后接收标准输入，但程序在没有等待的情况下退出。
预测原因
如果您跳过询问者提供的模式选择并直接启动模式，程序将按预期接受标准输入。因此，原因似乎是与标准输入相关的过程正在执行，而与之相关的某些状态已由询问者从初始状态更改。
我需要知道的
是否有任何方法可以将询问者所做的更改重置为初始状态并移动到所选模式？如果这很困难，我想知道在选择模式后是否有办法正确处理标准输入。事先非常感谢。
代码
#!/usr/bin/env node
'use strict'
{
const { Select } = require('enquirer')
const chalk = require('chalk')
const PI_START_TEXT = '3.'
const PI_BELOW_THE_DECIMAL_POINT = '1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679'
class PracticeMode {
start () {
const instruction = 'Keep typing in the number which fits the cursor position.'
// This program stops after executing the next line.
process.stdout.write(chalk.bold.green(instruction) + 'nn' + PI_START_TEXT)
const readline = require('readline');
readline.emitKeypressEvents(process.stdin)
process.stdin.setRawMode(true);
let currentIndex = 0
process.stdin.on('keypress', (char, key) => {
if (key.ctrl && key.name === 'c') {
process.exit();
} else if (currentIndex === 100) {
this.putsCongratulations()
process.exit();
} else if (char === PI_BELOW_THE_DECIMAL_POINT[currentIndex]) {
process.stdout.write(char)
currentIndex++
} else {
const scoreMessage = `Your score: ${currentIndex}`
const remaining_digits_text = this.make_remaining_digits_text(currentIndex)
console.log(chalk.red(remaining_digits_text) + 'n' + scoreMessage)
process.exit();
}
})
}
putsCongratulations () {
const headSpaces = ' '.repeat(6)
const congratulationsSentences = [
'Congratulations!',
'You have memorized the first 100 digits of pi.'
]
let congratulations = ''
congratulationsSentences.forEach(sentence => {
congratulations += headSpaces + sentence + 'n'
})
console.log(chalk.bold.green(congratulations))
}
make_remaining_digits_text (currentIndex) {
let remaining_digits_text = ''
const digitsNum = 100
const sectionDigitsNum = 10
const lineDigitsNum = 50
for (let i = currentIndex; i < digitsNum; i++) {
if (i === lineDigitsNum) {
remaining_digits_text += 'n' + ' '.repeat(PI_START_TEXT.length)
} else if (i % sectionDigitsNum === 0) {
remaining_digits_text += ' '
}
remaining_digits_text += PI_BELOW_THE_DECIMAL_POINT[i]
}
return remaining_digits_text
}
}
class Game {
constructor () {
this.practiceMode = 'PRACTICE MODE'
this.showPiDigits = 'SHOW PI DIGITS'
this.highScores = 'HIGH SCORES'
}
start () {
const modes = [
{ name: this.practiceMode, explanation: 'Check how many digits of pi you can name from the point you designated.' },
{ name: this.showPiDigits, explanation: 'Check the first 100 digits of pi.' },
{ name: this.highScores, explanation: 'Check the high scores.' }
]
const prompt = new Select({
name: 'mode',
message: 'Select your mode:',
choices: modes.map(mode => mode.name),
footer () {
const explanations = modes.map(mode => ' '.repeat(2) + mode.explanation)
return chalk.green('n' + explanations[this.index])
}
})
prompt.run()
.then(answer => {
switch (answer) {
case this.practiceMode:
// I have the problem here.
new PracticeMode().start()
break;
case this.showPiDigits:
break;
case this.highScores:
break;
}
})
}
}
function main () {
const welcomeMessage = '>'.repeat(10) + ' PI GAME ' + '<'.repeat(10)
console.log(chalk.bold.green(welcomeMessage))
// This doesn't work as intended.
new Game().start()
// If you run the next line instead, it works as intended.
// new PracticeMode().start()
}
main()
}
插入一行，如下所示：
let currentIndex = 0
process.stdin.resume()
process.stdin.on('keypress', (char, key) => {
参考：Node.jsのプロセス処理を少し学ぶ -阿希里斯日记