Show HN: Brain Frog – Can you be random enough for 11 lines of JavaScript?

Re:Show HN: Brain Frog – Can you be random enough for 11 lin... by escanor on Thursday June 25, 2026 @03:42AM (#48670211)

pure random player:

  (async function(punch, delay) {
    async function sleep(ms) {
      return new Promise((resolve, _) => {
        setTimeout(resolve, ms)
      })
    }
    
    for (let i = 0; i < 100; i++) {
      punch(['L', 'R'][(Math.random() * 2) | 0])
      await sleep(delay)
    }
  })(punch, 150)

"cheating" player:

  (async function(oracle, punch, delay) {
    async function sleep(ms) {
      return new Promise((resolve, _) => {
        setTimeout(resolve, ms)
      })
    }
    
    for (let i = 0; i < 100; i++) {
      punch((i + 1) < oracle.minForPrediction ? ['L', 'R'][(Math.random() * 2) | 0] : oracle.predictNextPunch() === 'L' ? 'R' : 'L')
      
      await sleep(delay)
    }
  })(oracle, punch, 150)

is it possible to do any better? i haven't fully read frog/oracle code

[ Parent | on HN ]

Re:Show HN: Brain Frog – Can you be random enough for 11 lin... by escanor on Thursday June 25, 2026 @04:00AM (#48670359)

it is:

  (async function(oracle, punch, delay) {
    async function sleep(ms) {
      return new Promise((resolve, _) => {
        setTimeout(resolve, ms)
      })
    }
    
    for (let i = 0; i < 100; i++) {
      const state = oracle._state
      const block = oracle.predictNextPunch()
      oracle._state = state
      
      punch(block === 'L' ? 'R' : 'L')
      
      await sleep(delay)
    }
  })(oracle, punch, 150)

[ Parent | on HN ]

Re:Show HN: Brain Frog – Can you be random enough for 11 lin... by emrtnn on Thursday June 25, 2026 @07:16AM (#48671797)

Less fancy hack here, intercept the prediction function on every punch and force the frog to take the opposite side. const realPunch = punch;

punch = function(myMove) {

  oracle.predictNextPunch = function() {
    return myMove === 'L' ? 'R' : 'L'; 
  };
  
  realPunch(myMove);

};

[ Parent | on HN ]

Re:Show HN: Brain Frog – Can you be random enough for 11 lin... by escanor on Friday June 26, 2026 @03:13AM (#48683360)

brilliant!

[ Parent | on HN ]