derekmc · April 16, 2025 11:21
diff --git a/keylog.html b/keylog.html

 <html>
  <head>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <style>
 /* CSS */
 body{whitespace:pre; font-family: monospace; }
 /* END */
    </style>
  </head>
  <body>
    <div class="markdown-src">
 <!-- HTML -->
 <button onclick='ref.interpret()'>Interpret Log</button>
 <!-- END -->
    </div>
    <div style="display: none;"></div>
    <script>
      let datakey = "__HTML_NOTES__:notedataid=tZJSX5lupP"
      let inframe = (window!=window.top)
      window.Note = {}
      window.Note.data =
 /* JSON */
 {"fulllog":""};
 /* END */
      (function(){
        window.Note.save = saveData
        window.Note.load = loadData
        window.Note.autoSave = autoSave
        function getNoteModule(){
          if(!window['Note']) window.Note = {}
          return window.Note
        }
        function loadData(){
          let note = getNoteModule()
          if(!inframe){
            try{
              let savedata = localStorage.getItem(datakey)
              if(savedata && savedata.length){
                note.data = JSON.parse(savedata)
              }
              window.addEventListener("message", onMessage)
            } catch(e){
              console.log("No local data")
              console.log(e)
            }
          } else {
            return note.data
          }
        }

        let firstLogCall = true
        let originalLogFunc = console.log
        function log(x, ...rest){
          if(firstLogCall)
            document.body.appendChild(document.createElement("hr"))
         else
            document.body.appendChild(document.createElement("br"))
          document.body.appendChild(
            document.createTextNode(x + " " + rest.join(" ")))
          firstLogCall = false
          originalLogFunc(x, ...rest)
        }
        console.log = log

        let SaveInterval = 500

        window.addEventListener("load", ()=>{
          convertMarkdown()
          autoSave()
          loadData() // dont wait for async
        })
        let saveIntervalRef = null
        function autoSave(enable){
          if(enable === undefined) enable = true
          clearInterval(saveIntervalRef)
          if(enable){
            saveIntervalRef = window.setInterval(saveData, SaveInterval)
          }
        }
        // this is preferred over a 'localstorage' polyfill for a frame,
        // so the programmer doesn't assume this is the browsers localstorage
        function saveData(){
          let note = getNoteModule()
          if(inframe){
            let msg_obj = {
              action: "saveData",
              data: JSON.stringify(note['data'])
            }
            let message = JSON.stringify(msg_obj)
            window.parent.postMessage(message)
          } else {
            localStorage.setItem(datakey, JSON.stringify(note['data']))
          }
        }
        let md_subs = [
          /(\n|^)\s*######\s([^\s#].*)\n*/g, "\n<h6 id=\"$2\">$2</h6>\n",
          /(\n|^)\s*#####\s([^\s#].*)\n*/g, "\n<h5 id=\"$2\">$2</h5>\n",
          /(\n|^)\s*####\s*([^\s#].*)\n*/g, "\n<h4 id=\"$2\">$2</h4>\n",
          /(\n|^)\s*###\s*([^\s#].*)\n*/g, "\n<h3 id=\"$2\">$2</h3>\n",
          /(\n|^)\s*##\s*([^\s#].*)\n*/g, "\n<h2 id=\"$2\">$2</h2>\n",
          /(\n|^)\s*#\s*([^\s#].*)\n*/g, "\n<h1 id=\"$2\">$2</h1>\n",
          /\n(\s*)[\*\-](.*)/g, '\n<ul><li>$2</li></ul>',
          /\n+\n(?=[^#\n])/g, "\n\n<br><br>",
          /\n+\n/g, "\n",
          /__([^_\n]*)__/g, "<b>$1</b>",
          /\*\*([^_\n]*)\*\*/g, "<b>$1</b>",
          /_([^_\n]*)_/g, "<i>$1</i>",
          /\*([^_\n]*)\*/g, "<i>$1</i>",
          /\!\[([^\]\n]*)\]\(([^\)\n]*)\)/g, "<img src=\"$2\" alt=\"$1\"></img>",
          /\[([^\]\n]*)\]\(([^\)\n]*)\)/g, "<a href=\"$2\" target=\"_blank\">$1</a>",
        ]
        function onMessage(){
          try{
            let message = JSON.parse(e.data)
            // console.log('received message', message)
            if(message.hasOwnProperty("event")){
              if(message.event == "keydown" && typeof keydown != "undefined"){
                keydown(message)
              }
              if(message.event == "keyup" && typeof keyup != "undefined"){
                keydown(message)
              }
            }
          } catch(e){
            console.warn("error processing message: " + e.data)
          }
        }
        function convertMarkdown(){
          let containers = document.getElementsByClassName("markdown-src")
          for(let j=0; j<containers.length; ++j){
            let container = containers[j]
            let src = container.innerHTML
            for(var i=0; i<md_subs.length-1; i += 2){
              var search = md_subs[i]
              var replace = md_subs[i+1]
              src = src.replace(search, replace)
            }
            container.innerHTML = src
          }
        }
      })()
      //window.addEventListener('load', htmlNotesMainFunc)
      //function htmlNotesMainFunc(){
 /* JS */
 let data = Note.data
 data.fulllog = ''

 let ref = {}
 let env = {} // constants
 env.maxdt = 5000
 env.mindt = 18
 env.maxkeyhold = 15*1000
 env.keyChars = {
  65: "abcdefghijklmnopqrstuvwxyz",
  '-65': "ABCDEFGHIJKLMNOPQRSTUVWXYZ",
  48: "0123456789",
  '-48':")!@#$%^&*(",
  187: "=,-./`",
  '-187': "+<_>?~",
  219: "[\\]'",
  '-219': "{|}\"",
  596: "0123456789*+",
  609: "-./"
 }
 env.keyNames = {
  8: "Backspace Tab",
  13: "Enter",
  16: "Shift Ctrl Alt Break CapsLock",
  27: "Escape",
  32: "Space PageUp PageDown End Home ArrowLeft ArrowUp ArrowRight ArrowDown",
  44: "PrintScreen Insert Delete",
  91: "MetaLeft MetaRight ContextMenu",
  144: "NumLock ScrollLock",
  112: "F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12"
 }

 window.addEventListener('load', main)

 function getCode(e){
  return e.keyCode
 }

 function json(x){
  return JSON.stringify(x)
 }
 function init(){
  env.keyCodes = {}
  for(let code in env.keyChars){
    let pre = ""
    let chars = env.keyChars[code]
    if(typeof code == "string"){
      code = parseInt(code)}
    if(code > 500) pre = "Numpad_"
    if(code < 0) code = -code + 1000
    for(let i=0; i<chars.length; ++i){
      env.keyCodes[pre + chars[i]] = code + i }
  }
  for(let code in env.keyNames){
    let pre = ""
    let names = env.keyNames[code].split(/\s+/)
    if(typeof code == "string"){
      code = parseInt(code)}
    if(code > 500) pre = "Numpad_"
    if(code < 0) code = -code + 1000
    for(let i=0; i<names.length; ++i){
      env.keyCodes[pre + names[i]] = code + i }
  }
  console.log(json(env.keyCodes))
 }

 function main(){
  init()
  console.log('main')

  let buffer = ""
  ref.interpret = interpret

  let realtime = { //timer
    now: ()=>Date.now(),
    timeout: (f, dt)=>setTimeout(f,dt),
  }
  let buff = {write: bufferWrite, flush: bufferFlush}
  
  let rawhandler = rawKeyAction(buff)

  let rawkey = keyActionWrapper(rawhandler)(realtime)
  let keys = rawkey
  window.addEventListener('keydown', keys.keydown)
  window.addEventListener('keyup', keys.keyup)
  setInterval(bufferFlush, 1000)

  function bufferWrite(s){
    if(buffer.length) buffer += " "
    buffer += s
  }
  function bufferFlush(){
    if(buffer.length == 0) return
    console.log("ready")
    console.info(buffer)
    data.fulllog += buffer + " "
    buffer = ""
  }
  function interpret(){
    console.log('===== raw log', data.fulllog)
    let log = readLog(data.fulllog)
    replay(log)
    data.fulllog = ""
  }
  function replay(log){
    let buffer2 = ""
    let buff = {write: bufferWrite, flush: bufferFlush}
    let chordAction = chordKeyAction(buff)
    let chordkey = keyActionWrapper(chordAction)
    replayLog(log, chordkey)

    let log2 = readLog(buffer2)
    console.info('log2', json(log2))
    console.log('=== chord log', writeLog(log2))
    sandwhichOrderLog(log2)
    console.log('sandwhich log', writeLog(log2))
    function bufferWrite(s){
      if(buffer2.length) buffer2 += " "
      buffer2 += s
    }
    function bufferFlush(){
      if(buffer2.length == 0) return
      console.log("ready")
      console.info(buffer)
      data.fulllog += buffer2 + " "
      buffer2 = ""
    }
  }
 }

 function readLog(s){
  let list = s.split(/\s+/)
  let result = []
  for(let i=0; i<list.length; ++i){
    let e = list[i]
    let dt = 0
    let j = e.indexOf(':')
    if(j > -1){
      dt =  parseInt(e.substring(j+1))
      e = e.substring(0, j)
    }
    let keys = e.split(',')
    let down = []
    let up = []
    for(let j=0; j<keys.length; ++j){
      let key = keys[j]
      let action = key[0]
      let code = key.substring(1)
      if(action == '+') down.push(code)
      else if(action == '-') up.push(code)
      else console.warn('unknown action: ' + action)
    }
    result.push({down, up, dt})
  }
  return result
 }
 function writeLog(log){
  let s = ''
  for(let i=0; i<log.length; ++i){
    let {up, down, dt} = log[i]
    if(s.length) s += ' '
    if(up.length)
      s += up.map(x=>'-' + x).join(',') +
        (dt>0? ":" + dt : "")
    if(down.length)
      s += down.map(x=>'+' + x).join(',') +
        (dt>0? ":" + dt : "")
  }
  return s
 }

 function replayLog(log, keyhandler){
  let t = 0
  let callbacks = []
  let replayTimer = {
    now: ()=>t,
    timeout: (f, dt)=>{
      callbacks.push([()=>f(), t+dt])
    }
  }
  let {keydown, keyup} = keyhandler(replayTimer)
  for(let i=0; i<log.length; ++i){
    let {up, down, dt} = log[i]
    t += dt
    nextCallback()
    up.forEach(code=>keyup({keyCode: code}))
    down.forEach(code=>keydown({keyCode: code}))
  }
  t += 60*1000
  nextCallback()

  function nextCallback(){
    callbacks.forEach(([f, s], i)=>{
      if(s < t){
        f()
        callbacks[i] = null
      }
    })
    callbacks = callbacks.filter(x=>x!==null)
  }
 }

 // simultaneous events get reordered so that they are
 // "sandwhiched" +a +b -b -a to enable chord recognition
 function sandwhichOrderLog(log){
  // lookup table for specific keycodes

  for(let q=0; q<2; ++q){
    let lookup = {}
    let searchname = ['down', 'up'][q]
    for(let i=0; i<log.length; ++i){
      let search = log[i][searchname]
      search.forEach((code, j)=>{
        if(!(code in lookup))
          lookup[code] = []
        lookup[code].push(i + j/search.length)
      })
    }
    for(let i=0; i<log.length; ++i){
      let {up, down} = log[i]
      let list = [up, down][q]
      let type = ['up', 'down'][q]
      let startOrEnd = [-1, log.length+1][q]
      let beforeOrAfter = [
        l=>(a,b)=>(b>l? a: Math.max(a,b)),
        l=>(a,b)=>(b<l? a: Math.min(a,b))][q]
      let cmp = (a, b) => b[1] - a[1]
      if(list.length > 1){
        // matched is the position of 
        // corresponding key events
        // to reorder the sandwhich
        let matched = []
        list.forEach((code, j)=>{
          let table = lookup[code] ?? []
          matched.push(table.reduce(beforeOrAfter(i), startOrEnd))
        })
        let zipped = list.map((x,i)=>[x, matched[i]])
        zipped.sort(cmp)
        let picked = zipped.map(x=>x[0])
        log[i][type] = picked
      } 
    }
  }
  return log
 }


 //curried object
 function keyActionWrapper(keyAction){
  return function(timer){
    //let activeKeys = {}
    let lasttime = 0
    return {keydown, keyup}

    function keydown(e){
      let code = getCode(e)
      if(e.repeat || code == 0) return
      let now = timer.now()
      let dt = now - lasttime
      lasttime = now
      keyAction('down', code, dt, timer)
    }
    function keyup(e){
      let code = getCode(e)
      //if(code == 0)// return
        console.log(`code, key, keyCode, e: ${e.code}, ${e.key}, ${e.keyCode}, ${json(e)}`)
      let s = ""
      for(let k in e)
        if(typeof e[k] != "function")
          s += ` ${k}: ${e[k]};`
      console.log(s)
      let now = timer.now()
      let dt = now - lasttime
      lasttime = now
      keyAction('up', code, dt, timer)
    }
  }
 }

 function rawKeyAction(buff){
  return action
  function action(name, code, dt){
    let action = {'up': '-', 'down': '+'}[name]
    if(!action) return
    dt = Math.round(Math.min(env.maxdt, dt))
    buff.write(action + code + ":" + dt)
  }
 }

 function chordKeyAction(buff){
  let pending = []
  return action

  function action(name, code, dt, timer){
    let action = {'up': '-', 'down': '+'}[name]
    if(!action) return
    dt = Math.round(Math.min(env.maxdt, dt))
    if(!pending.length) timer.timeout(processChords, env.mindt)
    pending.push({e: action + code, dt})
  }

  function processChords(){
    let sup = ""
    let sdown = ""
    let list = pending
    pending = []
    let dt_total = 0
    let up = []
    let down = []
    for(let i=0; i<list.length; ++i){
      let {e, dt} = list[i]
      if(e[0] == '-') sup += (sup.length? ',' : '') + e
      if(e[0] == '+') sdown += (sdown.length? ',' : '') + e
      dt_total += parseInt(dt)
    }
    // don't combine up and down events to be simultaneous,
    // as that has a special meaning for touch events that slide.
    if(sup.length && sdown.length){
      sup += ":" + dt_total
      sdown
      s = sup + ' ' + sdown
    } else {
      if(sup.length) s = sup
      if(sdown.length) s = sdown
      s += ":" + dt_total
    }
    buff.write(s)
  }
 }
 /* END */
      //}
    </script>
  </body>
 <html>

	<html>
	<head>
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<style>
	/* CSS */
	body{whitespace:pre; font-family: monospace; }
	/* END */
	</style>
	</head>
	<body>
	<div class="markdown-src">
	<!-- HTML -->
	<button onclick='ref.interpret()'>Interpret Log</button>
	<!-- END -->
	</div>
	<div style="display: none;"></div>
	<script>
	let datakey = "__HTML_NOTES__:notedataid=tZJSX5lupP"
	let inframe = (window!=window.top)
	window.Note = {}
	window.Note.data =
	/* JSON */
	{"fulllog":""};
	/* END */
	(function(){
	window.Note.save = saveData
	window.Note.load = loadData
	window.Note.autoSave = autoSave
	function getNoteModule(){
	if(!window['Note']) window.Note = {}
	return window.Note
	}
	function loadData(){
	let note = getNoteModule()
	if(!inframe){
	try{
	let savedata = localStorage.getItem(datakey)
	if(savedata && savedata.length){
	note.data = JSON.parse(savedata)
	}
	window.addEventListener("message", onMessage)
	} catch(e){
	console.log("No local data")
	console.log(e)
	}
	} else {
	return note.data
	}
	}

	let firstLogCall = true
	let originalLogFunc = console.log
	function log(x, ...rest){
	if(firstLogCall)
	document.body.appendChild(document.createElement("hr"))
	else
	document.body.appendChild(document.createElement("br"))
	document.body.appendChild(
	document.createTextNode(x + " " + rest.join(" ")))
	firstLogCall = false
	originalLogFunc(x, ...rest)
	}
	console.log = log

	let SaveInterval = 500

	window.addEventListener("load", ()=>{
	convertMarkdown()
	autoSave()
	loadData() // dont wait for async
	})
	let saveIntervalRef = null
	function autoSave(enable){
	if(enable === undefined) enable = true
	clearInterval(saveIntervalRef)
	if(enable){
	saveIntervalRef = window.setInterval(saveData, SaveInterval)
	}
	}
	// this is preferred over a 'localstorage' polyfill for a frame,
	// so the programmer doesn't assume this is the browsers localstorage
	function saveData(){
	let note = getNoteModule()
	if(inframe){
	let msg_obj = {
	action: "saveData",
	data: JSON.stringify(note['data'])
	}
	let message = JSON.stringify(msg_obj)
	window.parent.postMessage(message)
	} else {
	localStorage.setItem(datakey, JSON.stringify(note['data']))
	}
	}
	let md_subs = [
	/(\n\|^)\s######\s([^\s#].)\n*/g, "\n<h6 id=\"$2\">$2</h6>\n",
	/(\n\|^)\s#####\s([^\s#].)\n*/g, "\n<h5 id=\"$2\">$2</h5>\n",
	/(\n\|^)\s####\s([^\s#].)\n/g, "\n<h4 id=\"$2\">$2</h4>\n",
	/(\n\|^)\s###\s([^\s#].)\n/g, "\n<h3 id=\"$2\">$2</h3>\n",
	/(\n\|^)\s##\s([^\s#].)\n/g, "\n<h2 id=\"$2\">$2</h2>\n",
	/(\n\|^)\s#\s([^\s#].)\n/g, "\n<h1 id=\"$2\">$2</h1>\n",
	/\n(\s)[\\-](.*)/g, '\n<ul><li>$2</li></ul>',
	/\n+\n(?=[^#\n])/g, "\n\n<br><br>",
	/\n+\n/g, "\n",
	/__([^_\n]*)__/g, "<b>$1</b>",
	/\\([^_\n])\\*/g, "<b>$1</b>",
	/_([^_\n]*)_/g, "<i>$1</i>",
	/\([^_\n])\*/g, "<i>$1</i>",
	/\!\[([^\]\n])\]\(([^\)\n])\)/g, "<img src=\"$2\" alt=\"$1\"></img>",
	/\[([^\]\n])\]\(([^\)\n])\)/g, "<a href=\"$2\" target=\"_blank\">$1</a>",
	]
	function onMessage(){
	try{
	let message = JSON.parse(e.data)
	// console.log('received message', message)
	if(message.hasOwnProperty("event")){
	if(message.event == "keydown" && typeof keydown != "undefined"){
	keydown(message)
	}
	if(message.event == "keyup" && typeof keyup != "undefined"){
	keydown(message)
	}
	}
	} catch(e){
	console.warn("error processing message: " + e.data)
	}
	}
	function convertMarkdown(){
	let containers = document.getElementsByClassName("markdown-src")
	for(let j=0; j<containers.length; ++j){
	let container = containers[j]
	let src = container.innerHTML
	for(var i=0; i<md_subs.length-1; i += 2){
	var search = md_subs[i]
	var replace = md_subs[i+1]
	src = src.replace(search, replace)
	}
	container.innerHTML = src
	}
	}
	})()
	//window.addEventListener('load', htmlNotesMainFunc)
	//function htmlNotesMainFunc(){
	/* JS */
	let data = Note.data
	data.fulllog = ''

	let ref = {}
	let env = {} // constants
	env.maxdt = 5000
	env.mindt = 18
	env.maxkeyhold = 15*1000
	env.keyChars = {
	65: "abcdefghijklmnopqrstuvwxyz",
	'-65': "ABCDEFGHIJKLMNOPQRSTUVWXYZ",
	48: "0123456789",
	'-48':")!@#$%^&*(",
	187: "=,-./`",
	'-187': "+<_>?~",
	219: "[\\]'",
	'-219': "{\|}\"",
	596: "0123456789*+",
	609: "-./"
	}
	env.keyNames = {
	8: "Backspace Tab",
	13: "Enter",
	16: "Shift Ctrl Alt Break CapsLock",
	27: "Escape",
	32: "Space PageUp PageDown End Home ArrowLeft ArrowUp ArrowRight ArrowDown",
	44: "PrintScreen Insert Delete",
	91: "MetaLeft MetaRight ContextMenu",
	144: "NumLock ScrollLock",
	112: "F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12"
	}

	window.addEventListener('load', main)

	function getCode(e){
	return e.keyCode
	}

	function json(x){
	return JSON.stringify(x)
	}
	function init(){
	env.keyCodes = {}
	for(let code in env.keyChars){
	let pre = ""
	let chars = env.keyChars[code]
	if(typeof code == "string"){
	code = parseInt(code)}
	if(code > 500) pre = "Numpad_"
	if(code < 0) code = -code + 1000
	for(let i=0; i<chars.length; ++i){
	env.keyCodes[pre + chars[i]] = code + i }
	}
	for(let code in env.keyNames){
	let pre = ""
	let names = env.keyNames[code].split(/\s+/)
	if(typeof code == "string"){
	code = parseInt(code)}
	if(code > 500) pre = "Numpad_"
	if(code < 0) code = -code + 1000
	for(let i=0; i<names.length; ++i){
	env.keyCodes[pre + names[i]] = code + i }
	}
	console.log(json(env.keyCodes))
	}

	function main(){
	init()
	console.log('main')

	let buffer = ""
	ref.interpret = interpret

	let realtime = { //timer
	now: ()=>Date.now(),
	timeout: (f, dt)=>setTimeout(f,dt),
	}
	let buff = {write: bufferWrite, flush: bufferFlush}

	let rawhandler = rawKeyAction(buff)

	let rawkey = keyActionWrapper(rawhandler)(realtime)
	let keys = rawkey
	window.addEventListener('keydown', keys.keydown)
	window.addEventListener('keyup', keys.keyup)
	setInterval(bufferFlush, 1000)

	function bufferWrite(s){
	if(buffer.length) buffer += " "
	buffer += s
	}
	function bufferFlush(){
	if(buffer.length == 0) return
	console.log("ready")
	console.info(buffer)
	data.fulllog += buffer + " "
	buffer = ""
	}
	function interpret(){
	console.log('===== raw log', data.fulllog)
	let log = readLog(data.fulllog)
	replay(log)
	data.fulllog = ""
	}
	function replay(log){
	let buffer2 = ""
	let buff = {write: bufferWrite, flush: bufferFlush}
	let chordAction = chordKeyAction(buff)
	let chordkey = keyActionWrapper(chordAction)
	replayLog(log, chordkey)

	let log2 = readLog(buffer2)
	console.info('log2', json(log2))
	console.log('=== chord log', writeLog(log2))
	sandwhichOrderLog(log2)
	console.log('sandwhich log', writeLog(log2))
	function bufferWrite(s){
	if(buffer2.length) buffer2 += " "
	buffer2 += s
	}
	function bufferFlush(){
	if(buffer2.length == 0) return
	console.log("ready")
	console.info(buffer)
	data.fulllog += buffer2 + " "
	buffer2 = ""
	}
	}
	}

	function readLog(s){
	let list = s.split(/\s+/)
	let result = []
	for(let i=0; i<list.length; ++i){
	let e = list[i]
	let dt = 0
	let j = e.indexOf(':')
	if(j > -1){
	dt = parseInt(e.substring(j+1))
	e = e.substring(0, j)
	}
	let keys = e.split(',')
	let down = []
	let up = []
	for(let j=0; j<keys.length; ++j){
	let key = keys[j]
	let action = key[0]
	let code = key.substring(1)
	if(action == '+') down.push(code)
	else if(action == '-') up.push(code)
	else console.warn('unknown action: ' + action)
	}
	result.push({down, up, dt})
	}
	return result
	}
	function writeLog(log){
	let s = ''
	for(let i=0; i<log.length; ++i){
	let {up, down, dt} = log[i]
	if(s.length) s += ' '
	if(up.length)
	s += up.map(x=>'-' + x).join(',') +
	(dt>0? ":" + dt : "")
	if(down.length)
	s += down.map(x=>'+' + x).join(',') +
	(dt>0? ":" + dt : "")
	}
	return s
	}

	function replayLog(log, keyhandler){
	let t = 0
	let callbacks = []
	let replayTimer = {
	now: ()=>t,
	timeout: (f, dt)=>{
	callbacks.push([()=>f(), t+dt])
	}
	}
	let {keydown, keyup} = keyhandler(replayTimer)
	for(let i=0; i<log.length; ++i){
	let {up, down, dt} = log[i]
	t += dt
	nextCallback()
	up.forEach(code=>keyup({keyCode: code}))
	down.forEach(code=>keydown({keyCode: code}))
	}
	t += 60*1000
	nextCallback()

	function nextCallback(){
	callbacks.forEach(([f, s], i)=>{
	if(s < t){
	f()
	callbacks[i] = null
	}
	})
	callbacks = callbacks.filter(x=>x!==null)
	}
	}

	// simultaneous events get reordered so that they are
	// "sandwhiched" +a +b -b -a to enable chord recognition
	function sandwhichOrderLog(log){
	// lookup table for specific keycodes

	for(let q=0; q<2; ++q){
	let lookup = {}
	let searchname = ['down', 'up'][q]
	for(let i=0; i<log.length; ++i){
	let search = log[i][searchname]
	search.forEach((code, j)=>{
	if(!(code in lookup))
	lookup[code] = []
	lookup[code].push(i + j/search.length)
	})
	}
	for(let i=0; i<log.length; ++i){
	let {up, down} = log[i]
	let list = [up, down][q]
	let type = ['up', 'down'][q]
	let startOrEnd = [-1, log.length+1][q]
	let beforeOrAfter = [
	l=>(a,b)=>(b>l? a: Math.max(a,b)),
	l=>(a,b)=>(b<l? a: Math.min(a,b))][q]
	let cmp = (a, b) => b[1] - a[1]
	if(list.length > 1){
	// matched is the position of
	// corresponding key events
	// to reorder the sandwhich
	let matched = []
	list.forEach((code, j)=>{
	let table = lookup[code] ?? []
	matched.push(table.reduce(beforeOrAfter(i), startOrEnd))
	})
	let zipped = list.map((x,i)=>[x, matched[i]])
	zipped.sort(cmp)
	let picked = zipped.map(x=>x[0])
	log[i][type] = picked
	}
	}
	}
	return log
	}


	//curried object
	function keyActionWrapper(keyAction){
	return function(timer){
	//let activeKeys = {}
	let lasttime = 0
	return {keydown, keyup}

	function keydown(e){
	let code = getCode(e)
	if(e.repeat \|\| code == 0) return
	let now = timer.now()
	let dt = now - lasttime
	lasttime = now
	keyAction('down', code, dt, timer)
	}
	function keyup(e){
	let code = getCode(e)
	//if(code == 0)// return
	console.log(`code, key, keyCode, e: ${e.code}, ${e.key}, ${e.keyCode}, ${json(e)}`)
	let s = ""
	for(let k in e)
	if(typeof e[k] != "function")
	s += ` ${k}: ${e[k]};`
	console.log(s)
	let now = timer.now()
	let dt = now - lasttime
	lasttime = now
	keyAction('up', code, dt, timer)
	}
	}
	}

	function rawKeyAction(buff){
	return action
	function action(name, code, dt){
	let action = {'up': '-', 'down': '+'}[name]
	if(!action) return
	dt = Math.round(Math.min(env.maxdt, dt))
	buff.write(action + code + ":" + dt)
	}
	}

	function chordKeyAction(buff){
	let pending = []
	return action

	function action(name, code, dt, timer){
	let action = {'up': '-', 'down': '+'}[name]
	if(!action) return
	dt = Math.round(Math.min(env.maxdt, dt))
	if(!pending.length) timer.timeout(processChords, env.mindt)
	pending.push({e: action + code, dt})
	}

	function processChords(){
	let sup = ""
	let sdown = ""
	let list = pending
	pending = []
	let dt_total = 0
	let up = []
	let down = []
	for(let i=0; i<list.length; ++i){
	let {e, dt} = list[i]
	if(e[0] == '-') sup += (sup.length? ',' : '') + e
	if(e[0] == '+') sdown += (sdown.length? ',' : '') + e
	dt_total += parseInt(dt)
	}
	// don't combine up and down events to be simultaneous,
	// as that has a special meaning for touch events that slide.
	if(sup.length && sdown.length){
	sup += ":" + dt_total
	sdown
	s = sup + ' ' + sdown
	} else {
	if(sup.length) s = sup
	if(sdown.length) s = sdown
	s += ":" + dt_total
	}
	buff.write(s)
	}
	}
	/* END */
	//}
	</script>
	</body>
	<html>