Lab 2 - Lexers.ipynb

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    "# Lab 2\n",
    "\n",
    "- It is recommended to **go through this file with a partner**. \n",
    "- Ensure to **ask** if anything is not clear - first your partner, then a lab helper.\n",
    "- You want to first go through the accompanying code of the lectures."
   ]
  },
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    "In this lab, you will write a full lexer for ``SIMP``. \n",
    "\n",
    "Writing a lexer consists of the following parts: \n",
    "1. Identifying all necessary tokens. \n",
    "2. Set up the tokenisation. \n",
    "3. Set up needed regular expressions.\n",
    "\n",
    "During this lab, you will want to work both with this file and the input file for the lexer generator, ``simp.mll``.\n",
    "Open this file now."
   ]
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  {
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   "id": "94317d1f",
   "metadata": {
    "kernel": "Python 3 (ipykernel)"
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   "outputs": [],
   "source": [
    "from jupyterquiz import display_quiz\n",
    "\n",
    "question_path=\"./\""
   ]
  },
  {
   "cell_type": "markdown",
   "id": "522be80e",
   "metadata": {
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    "## 1. Tokens \n",
    "\n",
    "Recall the description of ``SIMP``. \n",
    "\n",
    "```\n",
    "program ::=  [declarations;] commands \n",
    "declarations ::= declaration | declaration; declarations \n",
    "declaration ::= VAR identifier\n",
    "\n",
    "commands ::= command | command; commands\n",
    "command ::= identifier := exp | IF condexp THEN command | IF condexp THEN command ELSE command | WHILE condexp DO command | BEGIN program END | INPUT identifier | PRINT exp \n",
    "\n",
    "comp := = | != | <= | < | >= | >\n",
    "condexp := exp comp exp \n",
    "exp  ::= identifier | number | exp + exp | exp – exp | exp * exp | exp / exp | - exp \n",
    "```\n",
    "\n",
    "1.  Write down a suitable data type of tokens: "
   ]
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   "id": "ad7b1b0a",
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    "kernel": "OCaml 4.13"
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   "outputs": [
    {
     "ename": "error",
     "evalue": "compile_error",
     "output_type": "error",
     "traceback": [
      "File \"[8]\", line 3, characters 0-0:\nError: Syntax error\n"
     ]
    }
   ],
   "source": [
    "type token = (* TODO *)"
   ]
  },
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   "execution_count": 14,
   "id": "871ee8af",
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       "               data-shuffleanswers=\"True\"\n",
       "               data-preserveresponses=\"false\"\n",
       "               data-numquestions=\"1000000\"> <style>:root {\n",
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       ".InpLabel {\n",
       "    line-height: 34px;\n",
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       "    margin-right: 10px;\n",
       "    color: #101010;\n",
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       ".incorrect {\n",
       "    color: var(--incorrect-red);\n",
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       "var questionsgyiMpzJySwwZ=[\n",
       "    {\n",
       "        \"question\": \"What is your number of tokens?\",\n",
       "        \"type\": \"numeric\",\n",
       "        \"answers\": [\n",
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       "                \"feedback\": \"This seem to be too many tokens!\"\n",
       "            }\n",
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       "    }\n",
       "];\n",
       "    // Make a random ID\n",
       "function makeid(length) {\n",
       "    var result = [];\n",
       "    var characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';\n",
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       "    for (var i = 0; i < length; i++) {\n",
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       "    while (i--) {\n",
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       "    return shuffled.slice(0, size);\n",
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       "\n",
       "function printResponses(responsesContainer) {\n",
       "    var responses=JSON.parse(responsesContainer.dataset.responses);\n",
       "    var stringResponses='<B>IMPORTANT!</B>To preserve this answer sequence for submission, when you have finalized your answers: <ol> <li> Copy the text in this cell below \"Answer String\"</li> <li> Double click on the cell directly below the Answer String, labeled \"Replace Me\"</li> <li> Select the whole \"Replace Me\" text</li> <li> Paste in your answer string and press shift-Enter.</li><li>Save the notebook using the save icon or File->Save Notebook menu item</li></ul><br><br><br><b>Answer String:</b><br> ';\n",
       "    console.log(responses);\n",
       "    responses.forEach((response, index) => {\n",
       "        if (response) {\n",
       "            console.log(index + ': ' + response);\n",
       "            stringResponses+= index + ': ' + response +\"<BR>\";\n",
       "        }\n",
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       "    responsesContainer.innerHTML=stringResponses;\n",
       "}\n",
       "function check_mc() {\n",
       "    var id = this.id.split('-')[0];\n",
       "    //var response = this.id.split('-')[1];\n",
       "    //console.log(response);\n",
       "    //console.log(\"In check_mc(), id=\"+id);\n",
       "    //console.log(event.srcElement.id)           \n",
       "    //console.log(event.srcElement.dataset.correct)   \n",
       "    //console.log(event.srcElement.dataset.feedback)\n",
       "\n",
       "    var label = event.srcElement;\n",
       "    //console.log(label, label.nodeName);\n",
       "    var depth = 0;\n",
       "    while ((label.nodeName != \"LABEL\") && (depth < 20)) {\n",
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       "        console.log(depth, label);\n",
       "        depth++;\n",
       "    }\n",
       "\n",
       "\n",
       "\n",
       "    var answers = label.parentElement.children;\n",
       "\n",
       "    //console.log(answers);\n",
       "\n",
       "\n",
       "    // Split behavior based on multiple choice vs many choice:\n",
       "    var fb = document.getElementById(\"fb\" + id);\n",
       "\n",
       "\n",
       "\n",
       "\n",
       "    if (fb.dataset.numcorrect == 1) {\n",
       "        // What follows is for the saved responses stuff\n",
       "        var outerContainer = fb.parentElement.parentElement;\n",
       "        var responsesContainer = document.getElementById(\"responses\" + outerContainer.id);\n",
       "        if (responsesContainer) {\n",
       "            //console.log(responsesContainer);\n",
       "            var response = label.firstChild.innerText;\n",
       "            if (label.querySelector(\".QuizCode\")){\n",
       "                response+= label.querySelector(\".QuizCode\").firstChild.innerText;\n",
       "            }\n",
       "            console.log(response);\n",
       "            //console.log(document.getElementById(\"quizWrap\"+id));\n",
       "            var qnum = document.getElementById(\"quizWrap\"+id).dataset.qnum;\n",
       "            console.log(\"Question \" + qnum);\n",
       "            //console.log(id, \", got numcorrect=\",fb.dataset.numcorrect);\n",
       "            var responses=JSON.parse(responsesContainer.dataset.responses);\n",
       "            console.log(responses);\n",
       "            responses[qnum]= response;\n",
       "            responsesContainer.setAttribute('data-responses', JSON.stringify(responses));\n",
       "            printResponses(responsesContainer);\n",
       "        }\n",
       "        // End code to preserve responses\n",
       "        \n",
       "        for (var i = 0; i < answers.length; i++) {\n",
       "            var child = answers[i];\n",
       "            //console.log(child);\n",
       "            child.className = \"MCButton\";\n",
       "        }\n",
       "\n",
       "\n",
       "\n",
       "        if (label.dataset.correct == \"true\") {\n",
       "            // console.log(\"Correct action\");\n",
       "            if (\"feedback\" in label.dataset) {\n",
       "                fb.textContent = jaxify(label.dataset.feedback);\n",
       "            } else {\n",
       "                fb.textContent = \"Correct!\";\n",
       "            }\n",
       "            label.classList.add(\"correctButton\");\n",
       "\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"correct\");\n",
       "\n",
       "        } else {\n",
       "            if (\"feedback\" in label.dataset) {\n",
       "                fb.textContent = jaxify(label.dataset.feedback);\n",
       "            } else {\n",
       "                fb.textContent = \"Incorrect -- try again.\";\n",
       "            }\n",
       "            //console.log(\"Error action\");\n",
       "            label.classList.add(\"incorrectButton\");\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"incorrect\");\n",
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       "        var reset = false;\n",
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       "         if (label.dataset.correct == \"true\") {\n",
       "            if (\"feedback\" in label.dataset) {\n",
       "                feedback = jaxify(label.dataset.feedback);\n",
       "            } else {\n",
       "                feedback = \"Correct!\";\n",
       "            }\n",
       "            if (label.dataset.answered <= 0) {\n",
       "                if (fb.dataset.answeredcorrect < 0) {\n",
       "                    fb.dataset.answeredcorrect = 1;\n",
       "                    reset = true;\n",
       "                } else {\n",
       "                    fb.dataset.answeredcorrect++;\n",
       "                }\n",
       "                if (reset) {\n",
       "                    for (var i = 0; i < answers.length; i++) {\n",
       "                        var child = answers[i];\n",
       "                        child.className = \"MCButton\";\n",
       "                        child.dataset.answered = 0;\n",
       "                    }\n",
       "                }\n",
       "                label.classList.add(\"correctButton\");\n",
       "                label.dataset.answered = 1;\n",
       "                fb.className = \"Feedback\";\n",
       "                fb.classList.add(\"correct\");\n",
       "\n",
       "            }\n",
       "        } else {\n",
       "            if (\"feedback\" in label.dataset) {\n",
       "                feedback = jaxify(label.dataset.feedback);\n",
       "            } else {\n",
       "                feedback = \"Incorrect -- try again.\";\n",
       "            }\n",
       "            if (fb.dataset.answeredcorrect > 0) {\n",
       "                fb.dataset.answeredcorrect = -1;\n",
       "                reset = true;\n",
       "            } else {\n",
       "                fb.dataset.answeredcorrect--;\n",
       "            }\n",
       "\n",
       "            if (reset) {\n",
       "                for (var i = 0; i < answers.length; i++) {\n",
       "                    var child = answers[i];\n",
       "                    child.className = \"MCButton\";\n",
       "                    child.dataset.answered = 0;\n",
       "                }\n",
       "            }\n",
       "            label.classList.add(\"incorrectButton\");\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"incorrect\");\n",
       "        }\n",
       "        // What follows is for the saved responses stuff\n",
       "        var outerContainer = fb.parentElement.parentElement;\n",
       "        var responsesContainer = document.getElementById(\"responses\" + outerContainer.id);\n",
       "        if (responsesContainer) {\n",
       "            //console.log(responsesContainer);\n",
       "            var response = label.firstChild.innerText;\n",
       "            if (label.querySelector(\".QuizCode\")){\n",
       "                response+= label.querySelector(\".QuizCode\").firstChild.innerText;\n",
       "            }\n",
       "            console.log(response);\n",
       "            //console.log(document.getElementById(\"quizWrap\"+id));\n",
       "            var qnum = document.getElementById(\"quizWrap\"+id).dataset.qnum;\n",
       "            console.log(\"Question \" + qnum);\n",
       "            //console.log(id, \", got numcorrect=\",fb.dataset.numcorrect);\n",
       "            var responses=JSON.parse(responsesContainer.dataset.responses);\n",
       "            if (label.dataset.correct == \"true\") {\n",
       "                if (typeof(responses[qnum]) == \"object\"){\n",
       "                    if (!responses[qnum].includes(response))\n",
       "                        responses[qnum].push(response);\n",
       "                } else{\n",
       "                    responses[qnum]= [ response ];\n",
       "                }\n",
       "            } else {\n",
       "                responses[qnum]= response;\n",
       "            }\n",
       "            console.log(responses);\n",
       "            responsesContainer.setAttribute('data-responses', JSON.stringify(responses));\n",
       "            printResponses(responsesContainer);\n",
       "        }\n",
       "        // End save responses stuff\n",
       "\n",
       "\n",
       "\n",
       "        var numcorrect = fb.dataset.numcorrect;\n",
       "        var answeredcorrect = fb.dataset.answeredcorrect;\n",
       "        if (answeredcorrect >= 0) {\n",
       "            fb.textContent = feedback + \" [\" + answeredcorrect + \"/\" + numcorrect + \"]\";\n",
       "        } else {\n",
       "            fb.textContent = feedback + \" [\" + 0 + \"/\" + numcorrect + \"]\";\n",
       "        }\n",
       "\n",
       "\n",
       "    }\n",
       "\n",
       "    if (typeof MathJax != 'undefined') {\n",
       "        var version = MathJax.version;\n",
       "        console.log('MathJax version', version);\n",
       "        if (version[0] == \"2\") {\n",
       "            MathJax.Hub.Queue([\"Typeset\", MathJax.Hub]);\n",
       "        } else if (version[0] == \"3\") {\n",
       "            MathJax.typeset([fb]);\n",
       "        }\n",
       "    } else {\n",
       "        console.log('MathJax not detected');\n",
       "    }\n",
       "\n",
       "}\n",
       "\n",
       "function make_mc(qa, shuffle_answers, outerqDiv, qDiv, aDiv, id) {\n",
       "    var shuffled;\n",
       "    if (shuffle_answers == \"True\") {\n",
       "        //console.log(shuffle_answers+\" read as true\");\n",
       "        shuffled = getRandomSubarray(qa.answers, qa.answers.length);\n",
       "    } else {\n",
       "        //console.log(shuffle_answers+\" read as false\");\n",
       "        shuffled = qa.answers;\n",
       "    }\n",
       "\n",
       "\n",
       "    var num_correct = 0;\n",
       "\n",
       "\n",
       "\n",
       "    shuffled.forEach((item, index, ans_array) => {\n",
       "        //console.log(answer);\n",
       "\n",
       "        // Make input element\n",
       "        var inp = document.createElement(\"input\");\n",
       "        inp.type = \"radio\";\n",
       "        inp.id = \"quizo\" + id + index;\n",
       "        inp.style = \"display:none;\";\n",
       "        aDiv.append(inp);\n",
       "\n",
       "        //Make label for input element\n",
       "        var lab = document.createElement(\"label\");\n",
       "        lab.className = \"MCButton\";\n",
       "        lab.id = id + '-' + index;\n",
       "        lab.onclick = check_mc;\n",
       "        var aSpan = document.createElement('span');\n",
       "        aSpan.classsName = \"\";\n",
       "        //qDiv.id=\"quizQn\"+id+index;\n",
       "        if (\"answer\" in item) {\n",
       "            aSpan.innerHTML = jaxify(item.answer);\n",
       "            //aSpan.innerHTML=item.answer;\n",
       "        }\n",
       "        lab.append(aSpan);\n",
       "\n",
       "        // Create div for code inside question\n",
       "        var codeSpan;\n",
       "        if (\"code\" in item) {\n",
       "            codeSpan = document.createElement('span');\n",
       "            codeSpan.id = \"code\" + id + index;\n",
       "            codeSpan.className = \"QuizCode\";\n",
       "            var codePre = document.createElement('pre');\n",
       "            codeSpan.append(codePre);\n",
       "            var codeCode = document.createElement('code');\n",
       "            codePre.append(codeCode);\n",
       "            codeCode.innerHTML = item.code;\n",
       "            lab.append(codeSpan);\n",
       "            //console.log(codeSpan);\n",
       "        }\n",
       "\n",
       "        //lab.textContent=item.answer;\n",
       "\n",
       "        // Set the data attributes for the answer\n",
       "        lab.setAttribute('data-correct', item.correct);\n",
       "        if (item.correct) {\n",
       "            num_correct++;\n",
       "        }\n",
       "        if (\"feedback\" in item) {\n",
       "            lab.setAttribute('data-feedback', item.feedback);\n",
       "        }\n",
       "        lab.setAttribute('data-answered', 0);\n",
       "\n",
       "        aDiv.append(lab);\n",
       "\n",
       "    });\n",
       "\n",
       "    if (num_correct > 1) {\n",
       "        outerqDiv.className = \"ManyChoiceQn\";\n",
       "    } else {\n",
       "        outerqDiv.className = \"MultipleChoiceQn\";\n",
       "    }\n",
       "\n",
       "    return num_correct;\n",
       "\n",
       "}\n",
       "function check_numeric(ths, event) {\n",
       "\n",
       "    if (event.keyCode === 13) {\n",
       "        ths.blur();\n",
       "\n",
       "        var id = ths.id.split('-')[0];\n",
       "\n",
       "        var submission = ths.value;\n",
       "        if (submission.indexOf('/') != -1) {\n",
       "            var sub_parts = submission.split('/');\n",
       "            //console.log(sub_parts);\n",
       "            submission = sub_parts[0] / sub_parts[1];\n",
       "        }\n",
       "        //console.log(\"Reader entered\", submission);\n",
       "\n",
       "        if (\"precision\" in ths.dataset) {\n",
       "            var precision = ths.dataset.precision;\n",
       "            // console.log(\"1:\", submission)\n",
       "            submission = Math.round((1 * submission + Number.EPSILON) * 10 ** precision) / 10 ** precision;\n",
       "            // console.log(\"Rounded to \", submission, \" precision=\", precision  );\n",
       "        }\n",
       "\n",
       "\n",
       "        //console.log(\"In check_numeric(), id=\"+id);\n",
       "        //console.log(event.srcElement.id)           \n",
       "        //console.log(event.srcElement.dataset.feedback)\n",
       "\n",
       "        var fb = document.getElementById(\"fb\" + id);\n",
       "        fb.style.display = \"none\";\n",
       "        fb.textContent = \"Incorrect -- try again.\";\n",
       "\n",
       "        var answers = JSON.parse(ths.dataset.answers);\n",
       "        //console.log(answers);\n",
       "\n",
       "        var defaultFB = \"\";\n",
       "        var correct;\n",
       "        var done = false;\n",
       "        answers.every(answer => {\n",
       "            //console.log(answer.type);\n",
       "\n",
       "            correct = false;\n",
       "            // if (answer.type==\"value\"){\n",
       "            if ('value' in answer) {\n",
       "                if (submission == answer.value) {\n",
       "                    fb.textContent = jaxify(answer.feedback);\n",
       "                    correct = answer.correct;\n",
       "                    //console.log(answer.correct);\n",
       "                    done = true;\n",
       "                }\n",
       "                // } else if (answer.type==\"range\") {\n",
       "            } else if ('range' in answer) {\n",
       "                //console.log(answer.range);\n",
       "                if ((submission >= answer.range[0]) && (submission < answer.range[1])) {\n",
       "                    fb.textContent = jaxify(answer.feedback);\n",
       "                    correct = answer.correct;\n",
       "                    //console.log(answer.correct);\n",
       "                    done = true;\n",
       "                }\n",
       "            } else if (answer.type == \"default\") {\n",
       "                defaultFB = answer.feedback;\n",
       "            }\n",
       "            if (done) {\n",
       "                return false; // Break out of loop if this has been marked correct\n",
       "            } else {\n",
       "                return true; // Keep looking for case that includes this as a correct answer\n",
       "            }\n",
       "        });\n",
       "\n",
       "        if ((!done) && (defaultFB != \"\")) {\n",
       "            fb.innerHTML = jaxify(defaultFB);\n",
       "            //console.log(\"Default feedback\", defaultFB);\n",
       "        }\n",
       "\n",
       "        fb.style.display = \"block\";\n",
       "        if (correct) {\n",
       "            ths.className = \"Input-text\";\n",
       "            ths.classList.add(\"correctButton\");\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"correct\");\n",
       "        } else {\n",
       "            ths.className = \"Input-text\";\n",
       "            ths.classList.add(\"incorrectButton\");\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"incorrect\");\n",
       "        }\n",
       "\n",
       "        // What follows is for the saved responses stuff\n",
       "        var outerContainer = fb.parentElement.parentElement;\n",
       "        var responsesContainer = document.getElementById(\"responses\" + outerContainer.id);\n",
       "        if (responsesContainer) {\n",
       "            console.log(submission);\n",
       "            var qnum = document.getElementById(\"quizWrap\"+id).dataset.qnum;\n",
       "            //console.log(\"Question \" + qnum);\n",
       "            //console.log(id, \", got numcorrect=\",fb.dataset.numcorrect);\n",
       "            var responses=JSON.parse(responsesContainer.dataset.responses);\n",
       "            console.log(responses);\n",
       "            if (submission == ths.value){\n",
       "                responses[qnum]= submission;\n",
       "            } else {\n",
       "                responses[qnum]= ths.value + \"(\" + submission +\")\";\n",
       "            }\n",
       "            responsesContainer.setAttribute('data-responses', JSON.stringify(responses));\n",
       "            printResponses(responsesContainer);\n",
       "        }\n",
       "        // End code to preserve responses\n",
       "\n",
       "        if (typeof MathJax != 'undefined') {\n",
       "            var version = MathJax.version;\n",
       "            console.log('MathJax version', version);\n",
       "            if (version[0] == \"2\") {\n",
       "                MathJax.Hub.Queue([\"Typeset\", MathJax.Hub]);\n",
       "            } else if (version[0] == \"3\") {\n",
       "                MathJax.typeset([fb]);\n",
       "            }\n",
       "        } else {\n",
       "            console.log('MathJax not detected');\n",
       "        }\n",
       "        return false;\n",
       "    }\n",
       "\n",
       "}\n",
       "\n",
       "function isValid(el, charC) {\n",
       "    //console.log(\"Input char: \", charC);\n",
       "    if (charC == 46) {\n",
       "        if (el.value.indexOf('.') === -1) {\n",
       "            return true;\n",
       "        } else if (el.value.indexOf('/') != -1) {\n",
       "            var parts = el.value.split('/');\n",
       "            if (parts[1].indexOf('.') === -1) {\n",
       "                return true;\n",
       "            }\n",
       "        }\n",
       "        else {\n",
       "            return false;\n",
       "        }\n",
       "    } else if (charC == 47) {\n",
       "        if (el.value.indexOf('/') === -1) {\n",
       "            if ((el.value != \"\") && (el.value != \".\")) {\n",
       "                return true;\n",
       "            } else {\n",
       "                return false;\n",
       "            }\n",
       "        } else {\n",
       "            return false;\n",
       "        }\n",
       "    } else if (charC == 45) {\n",
       "        var edex = el.value.indexOf('e');\n",
       "        if (edex == -1) {\n",
       "            edex = el.value.indexOf('E');\n",
       "        }\n",
       "\n",
       "        if (el.value == \"\") {\n",
       "            return true;\n",
       "        } else if (edex == (el.value.length - 1)) { // If just after e or E\n",
       "            return true;\n",
       "        } else {\n",
       "            return false;\n",
       "        }\n",
       "    } else if (charC == 101) { // \"e\"\n",
       "        if ((el.value.indexOf('e') === -1) && (el.value.indexOf('E') === -1) && (el.value.indexOf('/') == -1)) {\n",
       "            // Prev symbol must be digit or decimal point:\n",
       "            if (el.value.slice(-1).search(/\\d/) >= 0) {\n",
       "                return true;\n",
       "            } else if (el.value.slice(-1).search(/\\./) >= 0) {\n",
       "                return true;\n",
       "            } else {\n",
       "                return false;\n",
       "            }\n",
       "        } else {\n",
       "            return false;\n",
       "        }\n",
       "    } else {\n",
       "        if (charC > 31 && (charC < 48 || charC > 57))\n",
       "            return false;\n",
       "    }\n",
       "    return true;\n",
       "}\n",
       "\n",
       "function numeric_keypress(evnt) {\n",
       "    var charC = (evnt.which) ? evnt.which : evnt.keyCode;\n",
       "\n",
       "    if (charC == 13) {\n",
       "        check_numeric(this, evnt);\n",
       "    } else {\n",
       "        return isValid(this, charC);\n",
       "    }\n",
       "}\n",
       "\n",
       "\n",
       "\n",
       "\n",
       "\n",
       "function make_numeric(qa, outerqDiv, qDiv, aDiv, id) {\n",
       "\n",
       "\n",
       "\n",
       "    //console.log(answer);\n",
       "\n",
       "\n",
       "    outerqDiv.className = \"NumericQn\";\n",
       "    aDiv.style.display = 'block';\n",
       "\n",
       "    var lab = document.createElement(\"label\");\n",
       "    lab.className = \"InpLabel\";\n",
       "    lab.textContent = \"Type numeric answer here:\";\n",
       "    aDiv.append(lab);\n",
       "\n",
       "    var inp = document.createElement(\"input\");\n",
       "    inp.type = \"text\";\n",
       "    //inp.id=\"input-\"+id;\n",
       "    inp.id = id + \"-0\";\n",
       "    inp.className = \"Input-text\";\n",
       "    inp.setAttribute('data-answers', JSON.stringify(qa.answers));\n",
       "    if (\"precision\" in qa) {\n",
       "        inp.setAttribute('data-precision', qa.precision);\n",
       "    }\n",
       "    aDiv.append(inp);\n",
       "    //console.log(inp);\n",
       "\n",
       "    //inp.addEventListener(\"keypress\", check_numeric);\n",
       "    //inp.addEventListener(\"keypress\", numeric_keypress);\n",
       "    /*\n",
       "    inp.addEventListener(\"keypress\", function(event) {\n",
       "        return numeric_keypress(this, event);\n",
       "    }\n",
       "                        );\n",
       "                        */\n",
       "    //inp.onkeypress=\"return numeric_keypress(this, event)\";\n",
       "    inp.onkeypress = numeric_keypress;\n",
       "    inp.onpaste = event => false;\n",
       "\n",
       "    inp.addEventListener(\"focus\", function (event) {\n",
       "        this.value = \"\";\n",
       "        return false;\n",
       "    }\n",
       "    );\n",
       "\n",
       "\n",
       "}\n",
       "function jaxify(string) {\n",
       "    var mystring = string;\n",
       "\n",
       "    var count = 0;\n",
       "    var loc = mystring.search(/([^\\\\]|^)(\\$)/);\n",
       "\n",
       "    var count2 = 0;\n",
       "    var loc2 = mystring.search(/([^\\\\]|^)(\\$\\$)/);\n",
       "\n",
       "    //console.log(loc);\n",
       "\n",
       "    while ((loc >= 0) || (loc2 >= 0)) {\n",
       "\n",
       "        /* Have to replace all the double $$ first with current implementation */\n",
       "        if (loc2 >= 0) {\n",
       "            if (count2 % 2 == 0) {\n",
       "                mystring = mystring.replace(/([^\\\\]|^)(\\$\\$)/, \"$1\\\\[\");\n",
       "            } else {\n",
       "                mystring = mystring.replace(/([^\\\\]|^)(\\$\\$)/, \"$1\\\\]\");\n",
       "            }\n",
       "            count2++;\n",
       "        } else {\n",
       "            if (count % 2 == 0) {\n",
       "                mystring = mystring.replace(/([^\\\\]|^)(\\$)/, \"$1\\\\(\");\n",
       "            } else {\n",
       "                mystring = mystring.replace(/([^\\\\]|^)(\\$)/, \"$1\\\\)\");\n",
       "            }\n",
       "            count++;\n",
       "        }\n",
       "        loc = mystring.search(/([^\\\\]|^)(\\$)/);\n",
       "        loc2 = mystring.search(/([^\\\\]|^)(\\$\\$)/);\n",
       "        //console.log(mystring,\", loc:\",loc,\", loc2:\",loc2);\n",
       "    }\n",
       "\n",
       "    //console.log(mystring);\n",
       "    return mystring;\n",
       "}\n",
       "\n",
       "\n",
       "function show_questions(json, mydiv) {\n",
       "    console.log('show_questions');\n",
       "    //var mydiv=document.getElementById(myid);\n",
       "    var shuffle_questions = mydiv.dataset.shufflequestions;\n",
       "    var num_questions = mydiv.dataset.numquestions;\n",
       "    var shuffle_answers = mydiv.dataset.shuffleanswers;\n",
       "\n",
       "    if (num_questions > json.length) {\n",
       "        num_questions = json.length;\n",
       "    }\n",
       "\n",
       "    var questions;\n",
       "    if ((num_questions < json.length) || (shuffle_questions == \"True\")) {\n",
       "        //console.log(num_questions+\",\"+json.length);\n",
       "        questions = getRandomSubarray(json, num_questions);\n",
       "    } else {\n",
       "        questions = json;\n",
       "    }\n",
       "\n",
       "    //console.log(\"SQ: \"+shuffle_questions+\", NQ: \" + num_questions + \", SA: \", shuffle_answers);\n",
       "\n",
       "    // Iterate over questions\n",
       "    questions.forEach((qa, index, array) => {\n",
       "        //console.log(qa.question); \n",
       "\n",
       "        var id = makeid(8);\n",
       "        //console.log(id);\n",
       "\n",
       "\n",
       "        // Create Div to contain question and answers\n",
       "        var iDiv = document.createElement('div');\n",
       "        //iDiv.id = 'quizWrap' + id + index;\n",
       "        iDiv.id = 'quizWrap' + id;\n",
       "        iDiv.className = 'Quiz';\n",
       "        iDiv.setAttribute('data-qnum', index);\n",
       "        mydiv.appendChild(iDiv);\n",
       "        // iDiv.innerHTML=qa.question;\n",
       "\n",
       "        var outerqDiv = document.createElement('div');\n",
       "        outerqDiv.id = \"OuterquizQn\" + id + index;\n",
       "\n",
       "        iDiv.append(outerqDiv);\n",
       "\n",
       "        // Create div to contain question part\n",
       "        var qDiv = document.createElement('div');\n",
       "        qDiv.id = \"quizQn\" + id + index;\n",
       "        //qDiv.textContent=qa.question;\n",
       "        qDiv.innerHTML = jaxify(qa.question);\n",
       "\n",
       "        outerqDiv.append(qDiv);\n",
       "\n",
       "        // Create div for code inside question\n",
       "        var codeDiv;\n",
       "        if (\"code\" in qa) {\n",
       "            codeDiv = document.createElement('div');\n",
       "            codeDiv.id = \"code\" + id + index;\n",
       "            codeDiv.className = \"QuizCode\";\n",
       "            var codePre = document.createElement('pre');\n",
       "            codeDiv.append(codePre);\n",
       "            var codeCode = document.createElement('code');\n",
       "            codePre.append(codeCode);\n",
       "            codeCode.innerHTML = qa.code;\n",
       "            outerqDiv.append(codeDiv);\n",
       "            //console.log(codeDiv);\n",
       "        }\n",
       "\n",
       "\n",
       "        // Create div to contain answer part\n",
       "        var aDiv = document.createElement('div');\n",
       "        aDiv.id = \"quizAns\" + id + index;\n",
       "        aDiv.className = 'Answer';\n",
       "        iDiv.append(aDiv);\n",
       "\n",
       "        //console.log(qa.type);\n",
       "\n",
       "        var num_correct;\n",
       "        if (qa.type == \"multiple_choice\") {\n",
       "            num_correct = make_mc(qa, shuffle_answers, outerqDiv, qDiv, aDiv, id);\n",
       "        } else if (qa.type == \"many_choice\") {\n",
       "            num_correct = make_mc(qa, shuffle_answers, outerqDiv, qDiv, aDiv, id);\n",
       "        } else if (qa.type == \"numeric\") {\n",
       "            //console.log(\"numeric\");\n",
       "            make_numeric(qa, outerqDiv, qDiv, aDiv, id);\n",
       "        }\n",
       "\n",
       "\n",
       "        //Make div for feedback\n",
       "        var fb = document.createElement(\"div\");\n",
       "        fb.id = \"fb\" + id;\n",
       "        //fb.style=\"font-size: 20px;text-align:center;\";\n",
       "        fb.className = \"Feedback\";\n",
       "        fb.setAttribute(\"data-answeredcorrect\", 0);\n",
       "        fb.setAttribute(\"data-numcorrect\", num_correct);\n",
       "        iDiv.append(fb);\n",
       "\n",
       "\n",
       "    });\n",
       "    var preserveResponses = mydiv.dataset.preserveresponses;\n",
       "    console.log(preserveResponses);\n",
       "    console.log(preserveResponses == \"true\");\n",
       "    if (preserveResponses == \"true\") {\n",
       "        console.log(preserveResponses);\n",
       "        // Create Div to contain record of answers\n",
       "        var iDiv = document.createElement('div');\n",
       "        iDiv.id = 'responses' + mydiv.id;\n",
       "        iDiv.className = 'JCResponses';\n",
       "        // Create a place to store responses as an empty array\n",
       "        iDiv.setAttribute('data-responses', '[]');\n",
       "\n",
       "        // Dummy Text\n",
       "        iDiv.innerHTML=\"<b>Select your answers and then follow the directions that will appear here.</b>\"\n",
       "        //iDiv.className = 'Quiz';\n",
       "        mydiv.appendChild(iDiv);\n",
       "    }\n",
       "//console.log(\"At end of show_questions\");\n",
       "    if (typeof MathJax != 'undefined') {\n",
       "        console.log(\"MathJax version\", MathJax.version);\n",
       "        var version = MathJax.version;\n",
       "        setTimeout(function(){\n",
       "            var version = MathJax.version;\n",
       "            console.log('After sleep, MathJax version', version);\n",
       "            if (version[0] == \"2\") {\n",
       "                MathJax.Hub.Queue([\"Typeset\", MathJax.Hub]);\n",
       "            } else if (version[0] == \"3\") {\n",
       "                MathJax.typeset([mydiv]);\n",
       "            }\n",
       "        }, 500);\n",
       "if (typeof version == 'undefined') {\n",
       "        } else\n",
       "        {\n",
       "            if (version[0] == \"2\") {\n",
       "                MathJax.Hub.Queue([\"Typeset\", MathJax.Hub]);\n",
       "            } else if (version[0] == \"3\") {\n",
       "                MathJax.typeset([mydiv]);\n",
       "            } else {\n",
       "                console.log(\"MathJax not found\");\n",
       "            }\n",
       "        }\n",
       "    }\n",
       "    return false;\n",
       "}\n",
       "\n",
       "        {\n",
       "        show_questions(questionsgyiMpzJySwwZ,  gyiMpzJySwwZ);\n",
       "        }\n",
       "        "
      ],
      "text/plain": [
       "<IPython.core.display.Javascript object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "display_quiz(question_path+\"questions21.json\")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "bdb19181",
   "metadata": {
    "kernel": "OCaml 4.13"
   },
   "source": [
    "2. Insert the definition of tokens into the user definitions of ``simp.mll``. "
   ]
  },
  {
   "cell_type": "markdown",
   "id": "d1990853",
   "metadata": {
    "kernel": "SoS"
   },
   "source": [
    "## 2. Define Rules For Tokens \n",
    "\n",
    "\n",
    "Let us start setting up the ``token`` function. "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "id": "c63f062e",
   "metadata": {
    "kernel": "Python 3 (ipykernel)"
   },
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div id=\"daZjhJIEdrjY\" data-shufflequestions=\"False\"\n",
       "               data-shuffleanswers=\"True\"\n",
       "               data-preserveresponses=\"false\"\n",
       "               data-numquestions=\"1000000\"> <style>:root {\n",
       "    --medium-slate-blue: #6f78ffff;\n",
       "    --orange-pantone: #f75c03ff;\n",
       "    --russian-violet: #392061ff;\n",
       "    --maximum-yellow-red: #ffc857ff;\n",
       "    --viridian-green: #119da4ff;\n",
       "    --incorrect-red: #c80202;\n",
       "    --correct-green: #009113;\n",
       "}\n",
       "\n",
       ".Quiz {\n",
       "    max-width: 600px;\n",
       "    margin-top: 15px;\n",
       "    margin-left: auto;\n",
       "    margin-right: auto;\n",
       "    margin-bottom: 15px;\n",
       "    padding-bottom: 4px;\n",
       "    padding-top: 4px;\n",
       "    line-height: 1.1;\n",
       "    font-size: 16pt;\n",
       "}\n",
       "\n",
       ".QuizCode {\n",
       "    font-size: 14pt;\n",
       "    margin-top: 10px;\n",
       "    margin-left: 20px;\n",
       "    margin-right: 20px;\n",
       "}\n",
       "\n",
       ".QuizCode>pre {\n",
       "    padding: 4px;\n",
       "}\n",
       "\n",
       ".Answer {\n",
       "    margin: 10px 0;\n",
       "    display: grid;\n",
       "    grid-template-columns: auto auto;\n",
       "    grid-gap: 10px;\n",
       "}\n",
       "\n",
       ".Feedback {\n",
       "    font-size: 16pt;\n",
       "    text-align: center;\n",
       "    min-height: 2em;\n",
       "}\n",
       "\n",
       ".Input {\n",
       "    align: left;\n",
       "    font-size: 20pt;\n",
       "}\n",
       "\n",
       ".Input-text {\n",
       "    display: block;\n",
       "    margin: 10px;\n",
       "    color: inherit;\n",
       "    width: 140px;\n",
       "    background-color: #c0c0c0;\n",
       "    color: #fff;\n",
       "    padding: 5px;\n",
       "    padding-left: 10px;\n",
       "    font-family: inherit;\n",
       "    font-size: 20px;\n",
       "    font-weight: inherit;\n",
       "    line-height: 20pt;\n",
       "    border: none;\n",
       "    border-radius: 0.2rem;\n",
       "    transition: box-shadow 0.1s);\n",
       "}\n",
       "\n",
       ".Input-text:focus {\n",
       "    outline: none;\n",
       "    background-color: #c0c0c0;\n",
       "    box-shadow: 0.6rem 0.8rem 1.4rem -0.5rem #999999;\n",
       "}\n",
       "\n",
       ".MCButton {\n",
       "    background: #fafafa;\n",
       "    border: 1px solid #eee;\n",
       "    border-radius: 10px;\n",
       "    padding: 10px;\n",
       "    font-size: 16px;\n",
       "    cursor: pointer;\n",
       "    text-align: center;\n",
       "}\n",
       "\n",
       ".MCButton p {\n",
       "    color: inherit;\n",
       "}\n",
       "\n",
       ".MultipleChoiceQn {\n",
       "    padding: 10px;\n",
       "    background: var(--medium-slate-blue);\n",
       "    color: #fafafa;\n",
       "    border-radius: 10px;\n",
       "}\n",
       "\n",
       ".ManyChoiceQn {\n",
       "    padding: 10px;\n",
       "    background: var(--orange-pantone);\n",
       "    color: #fafafa;\n",
       "    border-radius: 10px;\n",
       "}\n",
       "\n",
       ".NumericQn {\n",
       "    padding: 10px;\n",
       "    background: var(--russian-violet);\n",
       "    color: #fafafa;\n",
       "    border-radius: 10px;\n",
       "}\n",
       "\n",
       ".NumericQn p {\n",
       "    color: inherit;\n",
       "}\n",
       "\n",
       ".InpLabel {\n",
       "    line-height: 34px;\n",
       "    float: left;\n",
       "    margin-right: 10px;\n",
       "    color: #101010;\n",
       "    font-size: 15pt;\n",
       "}\n",
       "\n",
       ".incorrect {\n",
       "    color: var(--incorrect-red);\n",
       "}\n",
       "\n",
       ".correct {\n",
       "    color: var(--correct-green);\n",
       "}\n",
       "\n",
       ".correctButton {\n",
       "    /*\n",
       "    background: var(--correct-green);\n",
       "   */\n",
       "    animation: correct-anim 0.6s ease;\n",
       "    animation-fill-mode: forwards;\n",
       "    color: #fafafa;\n",
       "    box-shadow: inset 0px 0px 5px #555555;\n",
       "    outline: none;\n",
       "}\n",
       "\n",
       ".incorrectButton {\n",
       "    animation: incorrect-anim 0.8s ease;\n",
       "    animation-fill-mode: forwards;\n",
       "    color: #fafafa;\n",
       "    box-shadow: inset 0px 0px 5px #555555;\n",
       "    outline: none;\n",
       "}\n",
       "\n",
       "@keyframes incorrect-anim {\n",
       "    100% {\n",
       "        background-color: var(--incorrect-red);\n",
       "    }\n",
       "}\n",
       "\n",
       "@keyframes correct-anim {\n",
       "    100% {\n",
       "        background-color: var(--correct-green);\n",
       "    }\n",
       "}</style>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "application/javascript": [
       "var questionsdaZjhJIEdrjY=[\n",
       "    {\n",
       "        \"question\": \"Choose all of the following statements that are true.\",\n",
       "        \"type\": \"many_choice\",\n",
       "        \"answers\": [\n",
       "            {\n",
       "                \"answer\": \"The order in which the different rules are presented is relevant.\",\n",
       "                \"correct\": true,\n",
       "                \"feedback\": \"Correct - the pattern of the first rule is matched first.\"\n",
       "            },\n",
       "                        {\n",
       "                \"answer\": \"The rule for LTE should come before the rule for LT.\",\n",
       "                \"correct\": false,\n",
       "                \"feedback\": \"False - then <= would yield [LT; EQ].\"\n",
       "            },\n",
       "            {\n",
       "                \"answer\": \"We do not require rules for opening and closed brackets are lexed, as this is built into the lexer generator automatically.\",\n",
       "                \"correct\": false,\n",
       "                \"feedback\": \"False - we require to also set up rules for brackets.\"\n",
       "            },\n",
       "            {\n",
       "                \"answer\": \"The rule | '*' { STAR } states that we match the input string on the regular expression '*' - and in this case, the next token is STAR.\",\n",
       "                \"correct\": true,\n",
       "                \"feedback\": \"Correct.\"\n",
       "            }\n",
       "        ]\n",
       "    }\n",
       "];\n",
       "    // Make a random ID\n",
       "function makeid(length) {\n",
       "    var result = [];\n",
       "    var characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';\n",
       "    var charactersLength = characters.length;\n",
       "    for (var i = 0; i < length; i++) {\n",
       "        result.push(characters.charAt(Math.floor(Math.random() * charactersLength)));\n",
       "    }\n",
       "    return result.join('');\n",
       "}\n",
       "\n",
       "// Choose a random subset of an array. Can also be used to shuffle the array\n",
       "function getRandomSubarray(arr, size) {\n",
       "    var shuffled = arr.slice(0), i = arr.length, temp, index;\n",
       "    while (i--) {\n",
       "        index = Math.floor((i + 1) * Math.random());\n",
       "        temp = shuffled[index];\n",
       "        shuffled[index] = shuffled[i];\n",
       "        shuffled[i] = temp;\n",
       "    }\n",
       "    return shuffled.slice(0, size);\n",
       "}\n",
       "\n",
       "function printResponses(responsesContainer) {\n",
       "    var responses=JSON.parse(responsesContainer.dataset.responses);\n",
       "    var stringResponses='<B>IMPORTANT!</B>To preserve this answer sequence for submission, when you have finalized your answers: <ol> <li> Copy the text in this cell below \"Answer String\"</li> <li> Double click on the cell directly below the Answer String, labeled \"Replace Me\"</li> <li> Select the whole \"Replace Me\" text</li> <li> Paste in your answer string and press shift-Enter.</li><li>Save the notebook using the save icon or File->Save Notebook menu item</li></ul><br><br><br><b>Answer String:</b><br> ';\n",
       "    console.log(responses);\n",
       "    responses.forEach((response, index) => {\n",
       "        if (response) {\n",
       "            console.log(index + ': ' + response);\n",
       "            stringResponses+= index + ': ' + response +\"<BR>\";\n",
       "        }\n",
       "    });\n",
       "    responsesContainer.innerHTML=stringResponses;\n",
       "}\n",
       "function check_mc() {\n",
       "    var id = this.id.split('-')[0];\n",
       "    //var response = this.id.split('-')[1];\n",
       "    //console.log(response);\n",
       "    //console.log(\"In check_mc(), id=\"+id);\n",
       "    //console.log(event.srcElement.id)           \n",
       "    //console.log(event.srcElement.dataset.correct)   \n",
       "    //console.log(event.srcElement.dataset.feedback)\n",
       "\n",
       "    var label = event.srcElement;\n",
       "    //console.log(label, label.nodeName);\n",
       "    var depth = 0;\n",
       "    while ((label.nodeName != \"LABEL\") && (depth < 20)) {\n",
       "        label = label.parentElement;\n",
       "        console.log(depth, label);\n",
       "        depth++;\n",
       "    }\n",
       "\n",
       "\n",
       "\n",
       "    var answers = label.parentElement.children;\n",
       "\n",
       "    //console.log(answers);\n",
       "\n",
       "\n",
       "    // Split behavior based on multiple choice vs many choice:\n",
       "    var fb = document.getElementById(\"fb\" + id);\n",
       "\n",
       "\n",
       "\n",
       "\n",
       "    if (fb.dataset.numcorrect == 1) {\n",
       "        // What follows is for the saved responses stuff\n",
       "        var outerContainer = fb.parentElement.parentElement;\n",
       "        var responsesContainer = document.getElementById(\"responses\" + outerContainer.id);\n",
       "        if (responsesContainer) {\n",
       "            //console.log(responsesContainer);\n",
       "            var response = label.firstChild.innerText;\n",
       "            if (label.querySelector(\".QuizCode\")){\n",
       "                response+= label.querySelector(\".QuizCode\").firstChild.innerText;\n",
       "            }\n",
       "            console.log(response);\n",
       "            //console.log(document.getElementById(\"quizWrap\"+id));\n",
       "            var qnum = document.getElementById(\"quizWrap\"+id).dataset.qnum;\n",
       "            console.log(\"Question \" + qnum);\n",
       "            //console.log(id, \", got numcorrect=\",fb.dataset.numcorrect);\n",
       "            var responses=JSON.parse(responsesContainer.dataset.responses);\n",
       "            console.log(responses);\n",
       "            responses[qnum]= response;\n",
       "            responsesContainer.setAttribute('data-responses', JSON.stringify(responses));\n",
       "            printResponses(responsesContainer);\n",
       "        }\n",
       "        // End code to preserve responses\n",
       "        \n",
       "        for (var i = 0; i < answers.length; i++) {\n",
       "            var child = answers[i];\n",
       "            //console.log(child);\n",
       "            child.className = \"MCButton\";\n",
       "        }\n",
       "\n",
       "\n",
       "\n",
       "        if (label.dataset.correct == \"true\") {\n",
       "            // console.log(\"Correct action\");\n",
       "            if (\"feedback\" in label.dataset) {\n",
       "                fb.textContent = jaxify(label.dataset.feedback);\n",
       "            } else {\n",
       "                fb.textContent = \"Correct!\";\n",
       "            }\n",
       "            label.classList.add(\"correctButton\");\n",
       "\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"correct\");\n",
       "\n",
       "        } else {\n",
       "            if (\"feedback\" in label.dataset) {\n",
       "                fb.textContent = jaxify(label.dataset.feedback);\n",
       "            } else {\n",
       "                fb.textContent = \"Incorrect -- try again.\";\n",
       "            }\n",
       "            //console.log(\"Error action\");\n",
       "            label.classList.add(\"incorrectButton\");\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"incorrect\");\n",
       "        }\n",
       "    }\n",
       "    else {\n",
       "        var reset = false;\n",
       "        var feedback;\n",
       "         if (label.dataset.correct == \"true\") {\n",
       "            if (\"feedback\" in label.dataset) {\n",
       "                feedback = jaxify(label.dataset.feedback);\n",
       "            } else {\n",
       "                feedback = \"Correct!\";\n",
       "            }\n",
       "            if (label.dataset.answered <= 0) {\n",
       "                if (fb.dataset.answeredcorrect < 0) {\n",
       "                    fb.dataset.answeredcorrect = 1;\n",
       "                    reset = true;\n",
       "                } else {\n",
       "                    fb.dataset.answeredcorrect++;\n",
       "                }\n",
       "                if (reset) {\n",
       "                    for (var i = 0; i < answers.length; i++) {\n",
       "                        var child = answers[i];\n",
       "                        child.className = \"MCButton\";\n",
       "                        child.dataset.answered = 0;\n",
       "                    }\n",
       "                }\n",
       "                label.classList.add(\"correctButton\");\n",
       "                label.dataset.answered = 1;\n",
       "                fb.className = \"Feedback\";\n",
       "                fb.classList.add(\"correct\");\n",
       "\n",
       "            }\n",
       "        } else {\n",
       "            if (\"feedback\" in label.dataset) {\n",
       "                feedback = jaxify(label.dataset.feedback);\n",
       "            } else {\n",
       "                feedback = \"Incorrect -- try again.\";\n",
       "            }\n",
       "            if (fb.dataset.answeredcorrect > 0) {\n",
       "                fb.dataset.answeredcorrect = -1;\n",
       "                reset = true;\n",
       "            } else {\n",
       "                fb.dataset.answeredcorrect--;\n",
       "            }\n",
       "\n",
       "            if (reset) {\n",
       "                for (var i = 0; i < answers.length; i++) {\n",
       "                    var child = answers[i];\n",
       "                    child.className = \"MCButton\";\n",
       "                    child.dataset.answered = 0;\n",
       "                }\n",
       "            }\n",
       "            label.classList.add(\"incorrectButton\");\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"incorrect\");\n",
       "        }\n",
       "        // What follows is for the saved responses stuff\n",
       "        var outerContainer = fb.parentElement.parentElement;\n",
       "        var responsesContainer = document.getElementById(\"responses\" + outerContainer.id);\n",
       "        if (responsesContainer) {\n",
       "            //console.log(responsesContainer);\n",
       "            var response = label.firstChild.innerText;\n",
       "            if (label.querySelector(\".QuizCode\")){\n",
       "                response+= label.querySelector(\".QuizCode\").firstChild.innerText;\n",
       "            }\n",
       "            console.log(response);\n",
       "            //console.log(document.getElementById(\"quizWrap\"+id));\n",
       "            var qnum = document.getElementById(\"quizWrap\"+id).dataset.qnum;\n",
       "            console.log(\"Question \" + qnum);\n",
       "            //console.log(id, \", got numcorrect=\",fb.dataset.numcorrect);\n",
       "            var responses=JSON.parse(responsesContainer.dataset.responses);\n",
       "            if (label.dataset.correct == \"true\") {\n",
       "                if (typeof(responses[qnum]) == \"object\"){\n",
       "                    if (!responses[qnum].includes(response))\n",
       "                        responses[qnum].push(response);\n",
       "                } else{\n",
       "                    responses[qnum]= [ response ];\n",
       "                }\n",
       "            } else {\n",
       "                responses[qnum]= response;\n",
       "            }\n",
       "            console.log(responses);\n",
       "            responsesContainer.setAttribute('data-responses', JSON.stringify(responses));\n",
       "            printResponses(responsesContainer);\n",
       "        }\n",
       "        // End save responses stuff\n",
       "\n",
       "\n",
       "\n",
       "        var numcorrect = fb.dataset.numcorrect;\n",
       "        var answeredcorrect = fb.dataset.answeredcorrect;\n",
       "        if (answeredcorrect >= 0) {\n",
       "            fb.textContent = feedback + \" [\" + answeredcorrect + \"/\" + numcorrect + \"]\";\n",
       "        } else {\n",
       "            fb.textContent = feedback + \" [\" + 0 + \"/\" + numcorrect + \"]\";\n",
       "        }\n",
       "\n",
       "\n",
       "    }\n",
       "\n",
       "    if (typeof MathJax != 'undefined') {\n",
       "        var version = MathJax.version;\n",
       "        console.log('MathJax version', version);\n",
       "        if (version[0] == \"2\") {\n",
       "            MathJax.Hub.Queue([\"Typeset\", MathJax.Hub]);\n",
       "        } else if (version[0] == \"3\") {\n",
       "            MathJax.typeset([fb]);\n",
       "        }\n",
       "    } else {\n",
       "        console.log('MathJax not detected');\n",
       "    }\n",
       "\n",
       "}\n",
       "\n",
       "function make_mc(qa, shuffle_answers, outerqDiv, qDiv, aDiv, id) {\n",
       "    var shuffled;\n",
       "    if (shuffle_answers == \"True\") {\n",
       "        //console.log(shuffle_answers+\" read as true\");\n",
       "        shuffled = getRandomSubarray(qa.answers, qa.answers.length);\n",
       "    } else {\n",
       "        //console.log(shuffle_answers+\" read as false\");\n",
       "        shuffled = qa.answers;\n",
       "    }\n",
       "\n",
       "\n",
       "    var num_correct = 0;\n",
       "\n",
       "\n",
       "\n",
       "    shuffled.forEach((item, index, ans_array) => {\n",
       "        //console.log(answer);\n",
       "\n",
       "        // Make input element\n",
       "        var inp = document.createElement(\"input\");\n",
       "        inp.type = \"radio\";\n",
       "        inp.id = \"quizo\" + id + index;\n",
       "        inp.style = \"display:none;\";\n",
       "        aDiv.append(inp);\n",
       "\n",
       "        //Make label for input element\n",
       "        var lab = document.createElement(\"label\");\n",
       "        lab.className = \"MCButton\";\n",
       "        lab.id = id + '-' + index;\n",
       "        lab.onclick = check_mc;\n",
       "        var aSpan = document.createElement('span');\n",
       "        aSpan.classsName = \"\";\n",
       "        //qDiv.id=\"quizQn\"+id+index;\n",
       "        if (\"answer\" in item) {\n",
       "            aSpan.innerHTML = jaxify(item.answer);\n",
       "            //aSpan.innerHTML=item.answer;\n",
       "        }\n",
       "        lab.append(aSpan);\n",
       "\n",
       "        // Create div for code inside question\n",
       "        var codeSpan;\n",
       "        if (\"code\" in item) {\n",
       "            codeSpan = document.createElement('span');\n",
       "            codeSpan.id = \"code\" + id + index;\n",
       "            codeSpan.className = \"QuizCode\";\n",
       "            var codePre = document.createElement('pre');\n",
       "            codeSpan.append(codePre);\n",
       "            var codeCode = document.createElement('code');\n",
       "            codePre.append(codeCode);\n",
       "            codeCode.innerHTML = item.code;\n",
       "            lab.append(codeSpan);\n",
       "            //console.log(codeSpan);\n",
       "        }\n",
       "\n",
       "        //lab.textContent=item.answer;\n",
       "\n",
       "        // Set the data attributes for the answer\n",
       "        lab.setAttribute('data-correct', item.correct);\n",
       "        if (item.correct) {\n",
       "            num_correct++;\n",
       "        }\n",
       "        if (\"feedback\" in item) {\n",
       "            lab.setAttribute('data-feedback', item.feedback);\n",
       "        }\n",
       "        lab.setAttribute('data-answered', 0);\n",
       "\n",
       "        aDiv.append(lab);\n",
       "\n",
       "    });\n",
       "\n",
       "    if (num_correct > 1) {\n",
       "        outerqDiv.className = \"ManyChoiceQn\";\n",
       "    } else {\n",
       "        outerqDiv.className = \"MultipleChoiceQn\";\n",
       "    }\n",
       "\n",
       "    return num_correct;\n",
       "\n",
       "}\n",
       "function check_numeric(ths, event) {\n",
       "\n",
       "    if (event.keyCode === 13) {\n",
       "        ths.blur();\n",
       "\n",
       "        var id = ths.id.split('-')[0];\n",
       "\n",
       "        var submission = ths.value;\n",
       "        if (submission.indexOf('/') != -1) {\n",
       "            var sub_parts = submission.split('/');\n",
       "            //console.log(sub_parts);\n",
       "            submission = sub_parts[0] / sub_parts[1];\n",
       "        }\n",
       "        //console.log(\"Reader entered\", submission);\n",
       "\n",
       "        if (\"precision\" in ths.dataset) {\n",
       "            var precision = ths.dataset.precision;\n",
       "            // console.log(\"1:\", submission)\n",
       "            submission = Math.round((1 * submission + Number.EPSILON) * 10 ** precision) / 10 ** precision;\n",
       "            // console.log(\"Rounded to \", submission, \" precision=\", precision  );\n",
       "        }\n",
       "\n",
       "\n",
       "        //console.log(\"In check_numeric(), id=\"+id);\n",
       "        //console.log(event.srcElement.id)           \n",
       "        //console.log(event.srcElement.dataset.feedback)\n",
       "\n",
       "        var fb = document.getElementById(\"fb\" + id);\n",
       "        fb.style.display = \"none\";\n",
       "        fb.textContent = \"Incorrect -- try again.\";\n",
       "\n",
       "        var answers = JSON.parse(ths.dataset.answers);\n",
       "        //console.log(answers);\n",
       "\n",
       "        var defaultFB = \"\";\n",
       "        var correct;\n",
       "        var done = false;\n",
       "        answers.every(answer => {\n",
       "            //console.log(answer.type);\n",
       "\n",
       "            correct = false;\n",
       "            // if (answer.type==\"value\"){\n",
       "            if ('value' in answer) {\n",
       "                if (submission == answer.value) {\n",
       "                    fb.textContent = jaxify(answer.feedback);\n",
       "                    correct = answer.correct;\n",
       "                    //console.log(answer.correct);\n",
       "                    done = true;\n",
       "                }\n",
       "                // } else if (answer.type==\"range\") {\n",
       "            } else if ('range' in answer) {\n",
       "                //console.log(answer.range);\n",
       "                if ((submission >= answer.range[0]) && (submission < answer.range[1])) {\n",
       "                    fb.textContent = jaxify(answer.feedback);\n",
       "                    correct = answer.correct;\n",
       "                    //console.log(answer.correct);\n",
       "                    done = true;\n",
       "                }\n",
       "            } else if (answer.type == \"default\") {\n",
       "                defaultFB = answer.feedback;\n",
       "            }\n",
       "            if (done) {\n",
       "                return false; // Break out of loop if this has been marked correct\n",
       "            } else {\n",
       "                return true; // Keep looking for case that includes this as a correct answer\n",
       "            }\n",
       "        });\n",
       "\n",
       "        if ((!done) && (defaultFB != \"\")) {\n",
       "            fb.innerHTML = jaxify(defaultFB);\n",
       "            //console.log(\"Default feedback\", defaultFB);\n",
       "        }\n",
       "\n",
       "        fb.style.display = \"block\";\n",
       "        if (correct) {\n",
       "            ths.className = \"Input-text\";\n",
       "            ths.classList.add(\"correctButton\");\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"correct\");\n",
       "        } else {\n",
       "            ths.className = \"Input-text\";\n",
       "            ths.classList.add(\"incorrectButton\");\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"incorrect\");\n",
       "        }\n",
       "\n",
       "        // What follows is for the saved responses stuff\n",
       "        var outerContainer = fb.parentElement.parentElement;\n",
       "        var responsesContainer = document.getElementById(\"responses\" + outerContainer.id);\n",
       "        if (responsesContainer) {\n",
       "            console.log(submission);\n",
       "            var qnum = document.getElementById(\"quizWrap\"+id).dataset.qnum;\n",
       "            //console.log(\"Question \" + qnum);\n",
       "            //console.log(id, \", got numcorrect=\",fb.dataset.numcorrect);\n",
       "            var responses=JSON.parse(responsesContainer.dataset.responses);\n",
       "            console.log(responses);\n",
       "            if (submission == ths.value){\n",
       "                responses[qnum]= submission;\n",
       "            } else {\n",
       "                responses[qnum]= ths.value + \"(\" + submission +\")\";\n",
       "            }\n",
       "            responsesContainer.setAttribute('data-responses', JSON.stringify(responses));\n",
       "            printResponses(responsesContainer);\n",
       "        }\n",
       "        // End code to preserve responses\n",
       "\n",
       "        if (typeof MathJax != 'undefined') {\n",
       "            var version = MathJax.version;\n",
       "            console.log('MathJax version', version);\n",
       "            if (version[0] == \"2\") {\n",
       "                MathJax.Hub.Queue([\"Typeset\", MathJax.Hub]);\n",
       "            } else if (version[0] == \"3\") {\n",
       "                MathJax.typeset([fb]);\n",
       "            }\n",
       "        } else {\n",
       "            console.log('MathJax not detected');\n",
       "        }\n",
       "        return false;\n",
       "    }\n",
       "\n",
       "}\n",
       "\n",
       "function isValid(el, charC) {\n",
       "    //console.log(\"Input char: \", charC);\n",
       "    if (charC == 46) {\n",
       "        if (el.value.indexOf('.') === -1) {\n",
       "            return true;\n",
       "        } else if (el.value.indexOf('/') != -1) {\n",
       "            var parts = el.value.split('/');\n",
       "            if (parts[1].indexOf('.') === -1) {\n",
       "                return true;\n",
       "            }\n",
       "        }\n",
       "        else {\n",
       "            return false;\n",
       "        }\n",
       "    } else if (charC == 47) {\n",
       "        if (el.value.indexOf('/') === -1) {\n",
       "            if ((el.value != \"\") && (el.value != \".\")) {\n",
       "                return true;\n",
       "            } else {\n",
       "                return false;\n",
       "            }\n",
       "        } else {\n",
       "            return false;\n",
       "        }\n",
       "    } else if (charC == 45) {\n",
       "        var edex = el.value.indexOf('e');\n",
       "        if (edex == -1) {\n",
       "            edex = el.value.indexOf('E');\n",
       "        }\n",
       "\n",
       "        if (el.value == \"\") {\n",
       "            return true;\n",
       "        } else if (edex == (el.value.length - 1)) { // If just after e or E\n",
       "            return true;\n",
       "        } else {\n",
       "            return false;\n",
       "        }\n",
       "    } else if (charC == 101) { // \"e\"\n",
       "        if ((el.value.indexOf('e') === -1) && (el.value.indexOf('E') === -1) && (el.value.indexOf('/') == -1)) {\n",
       "            // Prev symbol must be digit or decimal point:\n",
       "            if (el.value.slice(-1).search(/\\d/) >= 0) {\n",
       "                return true;\n",
       "            } else if (el.value.slice(-1).search(/\\./) >= 0) {\n",
       "                return true;\n",
       "            } else {\n",
       "                return false;\n",
       "            }\n",
       "        } else {\n",
       "            return false;\n",
       "        }\n",
       "    } else {\n",
       "        if (charC > 31 && (charC < 48 || charC > 57))\n",
       "            return false;\n",
       "    }\n",
       "    return true;\n",
       "}\n",
       "\n",
       "function numeric_keypress(evnt) {\n",
       "    var charC = (evnt.which) ? evnt.which : evnt.keyCode;\n",
       "\n",
       "    if (charC == 13) {\n",
       "        check_numeric(this, evnt);\n",
       "    } else {\n",
       "        return isValid(this, charC);\n",
       "    }\n",
       "}\n",
       "\n",
       "\n",
       "\n",
       "\n",
       "\n",
       "function make_numeric(qa, outerqDiv, qDiv, aDiv, id) {\n",
       "\n",
       "\n",
       "\n",
       "    //console.log(answer);\n",
       "\n",
       "\n",
       "    outerqDiv.className = \"NumericQn\";\n",
       "    aDiv.style.display = 'block';\n",
       "\n",
       "    var lab = document.createElement(\"label\");\n",
       "    lab.className = \"InpLabel\";\n",
       "    lab.textContent = \"Type numeric answer here:\";\n",
       "    aDiv.append(lab);\n",
       "\n",
       "    var inp = document.createElement(\"input\");\n",
       "    inp.type = \"text\";\n",
       "    //inp.id=\"input-\"+id;\n",
       "    inp.id = id + \"-0\";\n",
       "    inp.className = \"Input-text\";\n",
       "    inp.setAttribute('data-answers', JSON.stringify(qa.answers));\n",
       "    if (\"precision\" in qa) {\n",
       "        inp.setAttribute('data-precision', qa.precision);\n",
       "    }\n",
       "    aDiv.append(inp);\n",
       "    //console.log(inp);\n",
       "\n",
       "    //inp.addEventListener(\"keypress\", check_numeric);\n",
       "    //inp.addEventListener(\"keypress\", numeric_keypress);\n",
       "    /*\n",
       "    inp.addEventListener(\"keypress\", function(event) {\n",
       "        return numeric_keypress(this, event);\n",
       "    }\n",
       "                        );\n",
       "                        */\n",
       "    //inp.onkeypress=\"return numeric_keypress(this, event)\";\n",
       "    inp.onkeypress = numeric_keypress;\n",
       "    inp.onpaste = event => false;\n",
       "\n",
       "    inp.addEventListener(\"focus\", function (event) {\n",
       "        this.value = \"\";\n",
       "        return false;\n",
       "    }\n",
       "    );\n",
       "\n",
       "\n",
       "}\n",
       "function jaxify(string) {\n",
       "    var mystring = string;\n",
       "\n",
       "    var count = 0;\n",
       "    var loc = mystring.search(/([^\\\\]|^)(\\$)/);\n",
       "\n",
       "    var count2 = 0;\n",
       "    var loc2 = mystring.search(/([^\\\\]|^)(\\$\\$)/);\n",
       "\n",
       "    //console.log(loc);\n",
       "\n",
       "    while ((loc >= 0) || (loc2 >= 0)) {\n",
       "\n",
       "        /* Have to replace all the double $$ first with current implementation */\n",
       "        if (loc2 >= 0) {\n",
       "            if (count2 % 2 == 0) {\n",
       "                mystring = mystring.replace(/([^\\\\]|^)(\\$\\$)/, \"$1\\\\[\");\n",
       "            } else {\n",
       "                mystring = mystring.replace(/([^\\\\]|^)(\\$\\$)/, \"$1\\\\]\");\n",
       "            }\n",
       "            count2++;\n",
       "        } else {\n",
       "            if (count % 2 == 0) {\n",
       "                mystring = mystring.replace(/([^\\\\]|^)(\\$)/, \"$1\\\\(\");\n",
       "            } else {\n",
       "                mystring = mystring.replace(/([^\\\\]|^)(\\$)/, \"$1\\\\)\");\n",
       "            }\n",
       "            count++;\n",
       "        }\n",
       "        loc = mystring.search(/([^\\\\]|^)(\\$)/);\n",
       "        loc2 = mystring.search(/([^\\\\]|^)(\\$\\$)/);\n",
       "        //console.log(mystring,\", loc:\",loc,\", loc2:\",loc2);\n",
       "    }\n",
       "\n",
       "    //console.log(mystring);\n",
       "    return mystring;\n",
       "}\n",
       "\n",
       "\n",
       "function show_questions(json, mydiv) {\n",
       "    console.log('show_questions');\n",
       "    //var mydiv=document.getElementById(myid);\n",
       "    var shuffle_questions = mydiv.dataset.shufflequestions;\n",
       "    var num_questions = mydiv.dataset.numquestions;\n",
       "    var shuffle_answers = mydiv.dataset.shuffleanswers;\n",
       "\n",
       "    if (num_questions > json.length) {\n",
       "        num_questions = json.length;\n",
       "    }\n",
       "\n",
       "    var questions;\n",
       "    if ((num_questions < json.length) || (shuffle_questions == \"True\")) {\n",
       "        //console.log(num_questions+\",\"+json.length);\n",
       "        questions = getRandomSubarray(json, num_questions);\n",
       "    } else {\n",
       "        questions = json;\n",
       "    }\n",
       "\n",
       "    //console.log(\"SQ: \"+shuffle_questions+\", NQ: \" + num_questions + \", SA: \", shuffle_answers);\n",
       "\n",
       "    // Iterate over questions\n",
       "    questions.forEach((qa, index, array) => {\n",
       "        //console.log(qa.question); \n",
       "\n",
       "        var id = makeid(8);\n",
       "        //console.log(id);\n",
       "\n",
       "\n",
       "        // Create Div to contain question and answers\n",
       "        var iDiv = document.createElement('div');\n",
       "        //iDiv.id = 'quizWrap' + id + index;\n",
       "        iDiv.id = 'quizWrap' + id;\n",
       "        iDiv.className = 'Quiz';\n",
       "        iDiv.setAttribute('data-qnum', index);\n",
       "        mydiv.appendChild(iDiv);\n",
       "        // iDiv.innerHTML=qa.question;\n",
       "\n",
       "        var outerqDiv = document.createElement('div');\n",
       "        outerqDiv.id = \"OuterquizQn\" + id + index;\n",
       "\n",
       "        iDiv.append(outerqDiv);\n",
       "\n",
       "        // Create div to contain question part\n",
       "        var qDiv = document.createElement('div');\n",
       "        qDiv.id = \"quizQn\" + id + index;\n",
       "        //qDiv.textContent=qa.question;\n",
       "        qDiv.innerHTML = jaxify(qa.question);\n",
       "\n",
       "        outerqDiv.append(qDiv);\n",
       "\n",
       "        // Create div for code inside question\n",
       "        var codeDiv;\n",
       "        if (\"code\" in qa) {\n",
       "            codeDiv = document.createElement('div');\n",
       "            codeDiv.id = \"code\" + id + index;\n",
       "            codeDiv.className = \"QuizCode\";\n",
       "            var codePre = document.createElement('pre');\n",
       "            codeDiv.append(codePre);\n",
       "            var codeCode = document.createElement('code');\n",
       "            codePre.append(codeCode);\n",
       "            codeCode.innerHTML = qa.code;\n",
       "            outerqDiv.append(codeDiv);\n",
       "            //console.log(codeDiv);\n",
       "        }\n",
       "\n",
       "\n",
       "        // Create div to contain answer part\n",
       "        var aDiv = document.createElement('div');\n",
       "        aDiv.id = \"quizAns\" + id + index;\n",
       "        aDiv.className = 'Answer';\n",
       "        iDiv.append(aDiv);\n",
       "\n",
       "        //console.log(qa.type);\n",
       "\n",
       "        var num_correct;\n",
       "        if (qa.type == \"multiple_choice\") {\n",
       "            num_correct = make_mc(qa, shuffle_answers, outerqDiv, qDiv, aDiv, id);\n",
       "        } else if (qa.type == \"many_choice\") {\n",
       "            num_correct = make_mc(qa, shuffle_answers, outerqDiv, qDiv, aDiv, id);\n",
       "        } else if (qa.type == \"numeric\") {\n",
       "            //console.log(\"numeric\");\n",
       "            make_numeric(qa, outerqDiv, qDiv, aDiv, id);\n",
       "        }\n",
       "\n",
       "\n",
       "        //Make div for feedback\n",
       "        var fb = document.createElement(\"div\");\n",
       "        fb.id = \"fb\" + id;\n",
       "        //fb.style=\"font-size: 20px;text-align:center;\";\n",
       "        fb.className = \"Feedback\";\n",
       "        fb.setAttribute(\"data-answeredcorrect\", 0);\n",
       "        fb.setAttribute(\"data-numcorrect\", num_correct);\n",
       "        iDiv.append(fb);\n",
       "\n",
       "\n",
       "    });\n",
       "    var preserveResponses = mydiv.dataset.preserveresponses;\n",
       "    console.log(preserveResponses);\n",
       "    console.log(preserveResponses == \"true\");\n",
       "    if (preserveResponses == \"true\") {\n",
       "        console.log(preserveResponses);\n",
       "        // Create Div to contain record of answers\n",
       "        var iDiv = document.createElement('div');\n",
       "        iDiv.id = 'responses' + mydiv.id;\n",
       "        iDiv.className = 'JCResponses';\n",
       "        // Create a place to store responses as an empty array\n",
       "        iDiv.setAttribute('data-responses', '[]');\n",
       "\n",
       "        // Dummy Text\n",
       "        iDiv.innerHTML=\"<b>Select your answers and then follow the directions that will appear here.</b>\"\n",
       "        //iDiv.className = 'Quiz';\n",
       "        mydiv.appendChild(iDiv);\n",
       "    }\n",
       "//console.log(\"At end of show_questions\");\n",
       "    if (typeof MathJax != 'undefined') {\n",
       "        console.log(\"MathJax version\", MathJax.version);\n",
       "        var version = MathJax.version;\n",
       "        setTimeout(function(){\n",
       "            var version = MathJax.version;\n",
       "            console.log('After sleep, MathJax version', version);\n",
       "            if (version[0] == \"2\") {\n",
       "                MathJax.Hub.Queue([\"Typeset\", MathJax.Hub]);\n",
       "            } else if (version[0] == \"3\") {\n",
       "                MathJax.typeset([mydiv]);\n",
       "            }\n",
       "        }, 500);\n",
       "if (typeof version == 'undefined') {\n",
       "        } else\n",
       "        {\n",
       "            if (version[0] == \"2\") {\n",
       "                MathJax.Hub.Queue([\"Typeset\", MathJax.Hub]);\n",
       "            } else if (version[0] == \"3\") {\n",
       "                MathJax.typeset([mydiv]);\n",
       "            } else {\n",
       "                console.log(\"MathJax not found\");\n",
       "            }\n",
       "        }\n",
       "    }\n",
       "    return false;\n",
       "}\n",
       "\n",
       "        {\n",
       "        show_questions(questionsdaZjhJIEdrjY,  daZjhJIEdrjY);\n",
       "        }\n",
       "        "
      ],
      "text/plain": [
       "<IPython.core.display.Javascript object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "display_quiz(question_path+\"questions22.json\")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "c260d98f",
   "metadata": {
    "kernel": "SoS"
   },
   "source": [
    "1. Set up the ``token`` function such that \n",
    "    - The end-of-file symbol is recognized. \n",
    "    - An exception is thrown in case there is an unexpected character. You will want to define the exception in the user definitions. \n",
    "\n",
    "2. Include one rule for each token except identifers and integers. "
   ]
  },
  {
   "cell_type": "markdown",
   "id": "51765bcc",
   "metadata": {
    "kernel": "OCaml 4.13"
   },
   "source": [
    "Let's test whether your code runs."
   ]
  },
  {
   "cell_type": "markdown",
   "id": "805208da",
   "metadata": {
    "kernel": "SoS"
   },
   "source": [
    "**IMPORTANT** Jupyter Notebooks automatically saves some output information. \n",
    "Each time you change the ``simp.mll`` file and want to re-run the following commands, \n",
    "first choose in the menu Kernel -> Restart & Clear Output to ensure your changed file is used."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "id": "2158bbfa",
   "metadata": {
    "kernel": "OCaml 4.13"
   },
   "outputs": [],
   "source": [
    "#require \"jupyter.notebook\" ;;\n",
    "\n",
    "open Jupyter_notebook;;"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "id": "7ab86bcf",
   "metadata": {
    "kernel": "OCaml 4.13"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "62 states, 3074 transitions, table size 12668 bytes\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "- : Jupyter_notebook.Process.t =\n",
       "{Jupyter_notebook.Process.exit_status = Unix.WEXITED 0; stdout = None;\n",
       " stderr = None}\n"
      ]
     },
     "execution_count": 17,
     "metadata": {},
     "output_type": "execute_result"
    },
    {
     "data": {
      "text/plain": [
       "- : Jupyter_notebook.Process.t =\n",
       "{Jupyter_notebook.Process.exit_status = Unix.WEXITED 0; stdout = None;\n",
       " stderr = None}\n"
      ]
     },
     "execution_count": 17,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "Process.sh \"ocamllex simp.mll\";;\n",
    "Process.sh \"ocamlc -c simp.ml\";;"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "id": "3b5e8f50",
   "metadata": {
    "kernel": "OCaml 4.13"
   },
   "outputs": [],
   "source": [
    "#load \"simp.cmo\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "id": "d06bd2d1",
   "metadata": {
    "kernel": "OCaml 4.13"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "- : Lexing.lexbuf -> Simp.token = <fun>\n"
      ]
     },
     "execution_count": 19,
     "metadata": {},
     "output_type": "execute_result"
    },
    {
     "data": {
      "text/plain": [
       "val stream_to_list : Lexing.lexbuf -> Simp.token list = <fun>\n"
      ]
     },
     "execution_count": 19,
     "metadata": {},
     "output_type": "execute_result"
    },
    {
     "data": {
      "text/plain": [
       "val res : Simp.token list =\n",
       "  [Simp.WHILE; Simp.LT; Simp.EQ; Simp.BEGIN; Simp.ID \"READ\"; Simp.END;\n",
       "   Simp.PRINT; Simp.LTE]\n"
      ]
     },
     "execution_count": 19,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "Simp.token;;\n",
    "\n",
    "let rec stream_to_list buffer = \n",
    "    match Simp.token buffer with \n",
    "    | EOF -> []\n",
    "    | x -> x :: stream_to_list buffer\n",
    "\n",
    "let res = stream_to_list (Lexing.from_string \"WHILE < = BEGIN READ END PRINT <=\")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "921ba7d4",
   "metadata": {
    "kernel": "SoS"
   },
   "source": [
    "## 3. Set Up Regular Expressions \n",
    "\n",
    "We come to the last part, where you will ensure to set up the right regular expressions for white space, integers, and identifers. \n",
    "Remember that we want: \n",
    "- white space to be either a blank ``\" \"``, horizontal tabulator space ``\\t``, or the new line symbol ``\\n``.\n",
    "- integers to be a positive or negative number.\n",
    "- identifiers to be a letter followed by an arbitrary number of letters or numbers."
   ]
  },
  {
   "cell_type": "markdown",
   "id": "3115b11f",
   "metadata": {
    "kernel": "OCaml 4.13"
   },
   "source": [
    "1. Define patterns for white space, numbers, and identifiers. \n",
    "2. Add rule for white space, numbers and identifiers."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "id": "76de6ce2",
   "metadata": {
    "kernel": "Python 3 (ipykernel)"
   },
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div id=\"VkmOpExFoYfs\" data-shufflequestions=\"False\"\n",
       "               data-shuffleanswers=\"True\"\n",
       "               data-preserveresponses=\"false\"\n",
       "               data-numquestions=\"1000000\"> <style>:root {\n",
       "    --medium-slate-blue: #6f78ffff;\n",
       "    --orange-pantone: #f75c03ff;\n",
       "    --russian-violet: #392061ff;\n",
       "    --maximum-yellow-red: #ffc857ff;\n",
       "    --viridian-green: #119da4ff;\n",
       "    --incorrect-red: #c80202;\n",
       "    --correct-green: #009113;\n",
       "}\n",
       "\n",
       ".Quiz {\n",
       "    max-width: 600px;\n",
       "    margin-top: 15px;\n",
       "    margin-left: auto;\n",
       "    margin-right: auto;\n",
       "    margin-bottom: 15px;\n",
       "    padding-bottom: 4px;\n",
       "    padding-top: 4px;\n",
       "    line-height: 1.1;\n",
       "    font-size: 16pt;\n",
       "}\n",
       "\n",
       ".QuizCode {\n",
       "    font-size: 14pt;\n",
       "    margin-top: 10px;\n",
       "    margin-left: 20px;\n",
       "    margin-right: 20px;\n",
       "}\n",
       "\n",
       ".QuizCode>pre {\n",
       "    padding: 4px;\n",
       "}\n",
       "\n",
       ".Answer {\n",
       "    margin: 10px 0;\n",
       "    display: grid;\n",
       "    grid-template-columns: auto auto;\n",
       "    grid-gap: 10px;\n",
       "}\n",
       "\n",
       ".Feedback {\n",
       "    font-size: 16pt;\n",
       "    text-align: center;\n",
       "    min-height: 2em;\n",
       "}\n",
       "\n",
       ".Input {\n",
       "    align: left;\n",
       "    font-size: 20pt;\n",
       "}\n",
       "\n",
       ".Input-text {\n",
       "    display: block;\n",
       "    margin: 10px;\n",
       "    color: inherit;\n",
       "    width: 140px;\n",
       "    background-color: #c0c0c0;\n",
       "    color: #fff;\n",
       "    padding: 5px;\n",
       "    padding-left: 10px;\n",
       "    font-family: inherit;\n",
       "    font-size: 20px;\n",
       "    font-weight: inherit;\n",
       "    line-height: 20pt;\n",
       "    border: none;\n",
       "    border-radius: 0.2rem;\n",
       "    transition: box-shadow 0.1s);\n",
       "}\n",
       "\n",
       ".Input-text:focus {\n",
       "    outline: none;\n",
       "    background-color: #c0c0c0;\n",
       "    box-shadow: 0.6rem 0.8rem 1.4rem -0.5rem #999999;\n",
       "}\n",
       "\n",
       ".MCButton {\n",
       "    background: #fafafa;\n",
       "    border: 1px solid #eee;\n",
       "    border-radius: 10px;\n",
       "    padding: 10px;\n",
       "    font-size: 16px;\n",
       "    cursor: pointer;\n",
       "    text-align: center;\n",
       "}\n",
       "\n",
       ".MCButton p {\n",
       "    color: inherit;\n",
       "}\n",
       "\n",
       ".MultipleChoiceQn {\n",
       "    padding: 10px;\n",
       "    background: var(--medium-slate-blue);\n",
       "    color: #fafafa;\n",
       "    border-radius: 10px;\n",
       "}\n",
       "\n",
       ".ManyChoiceQn {\n",
       "    padding: 10px;\n",
       "    background: var(--orange-pantone);\n",
       "    color: #fafafa;\n",
       "    border-radius: 10px;\n",
       "}\n",
       "\n",
       ".NumericQn {\n",
       "    padding: 10px;\n",
       "    background: var(--russian-violet);\n",
       "    color: #fafafa;\n",
       "    border-radius: 10px;\n",
       "}\n",
       "\n",
       ".NumericQn p {\n",
       "    color: inherit;\n",
       "}\n",
       "\n",
       ".InpLabel {\n",
       "    line-height: 34px;\n",
       "    float: left;\n",
       "    margin-right: 10px;\n",
       "    color: #101010;\n",
       "    font-size: 15pt;\n",
       "}\n",
       "\n",
       ".incorrect {\n",
       "    color: var(--incorrect-red);\n",
       "}\n",
       "\n",
       ".correct {\n",
       "    color: var(--correct-green);\n",
       "}\n",
       "\n",
       ".correctButton {\n",
       "    /*\n",
       "    background: var(--correct-green);\n",
       "   */\n",
       "    animation: correct-anim 0.6s ease;\n",
       "    animation-fill-mode: forwards;\n",
       "    color: #fafafa;\n",
       "    box-shadow: inset 0px 0px 5px #555555;\n",
       "    outline: none;\n",
       "}\n",
       "\n",
       ".incorrectButton {\n",
       "    animation: incorrect-anim 0.8s ease;\n",
       "    animation-fill-mode: forwards;\n",
       "    color: #fafafa;\n",
       "    box-shadow: inset 0px 0px 5px #555555;\n",
       "    outline: none;\n",
       "}\n",
       "\n",
       "@keyframes incorrect-anim {\n",
       "    100% {\n",
       "        background-color: var(--incorrect-red);\n",
       "    }\n",
       "}\n",
       "\n",
       "@keyframes correct-anim {\n",
       "    100% {\n",
       "        background-color: var(--correct-green);\n",
       "    }\n",
       "}</style>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "application/javascript": [
       "var questionsVkmOpExFoYfs=[\n",
       "    {\n",
       "        \"question\": \"Choose all of the following statements that are true.\",\n",
       "        \"type\": \"many_choice\",\n",
       "        \"answers\": [\n",
       "            {\n",
       "                \"answer\": \"The rule for identifiers should be put before the rules of keywords.\",\n",
       "                \"correct\": false,\n",
       "                \"feedback\": \"False - then e.g. WHILE would be recognized as an identifier.\"\n",
       "            },\n",
       "                        {\n",
       "                \"answer\": \"The string  xyz23 + 45 should recognize Id xyz as first token.\",\n",
       "                \"correct\": false,\n",
       "                \"feedback\": \"False - it should recognize Id xzy23.\"\n",
       "            },\n",
       "            {\n",
       "                \"answer\": \"The function Lexing.lexeme converts a buffer into a string.\",\n",
       "                \"correct\": true,\n",
       "                \"feedback\": \"Correct.\"\n",
       "            },\n",
       "            {\n",
       "                \"answer\": \"In principle, we can use every regular expression in the definition of a pattern.\",\n",
       "                \"correct\": true,\n",
       "                \"feedback\": \"Correct.\"\n",
       "            }\n",
       "        ]\n",
       "    }\n",
       "];\n",
       "    // Make a random ID\n",
       "function makeid(length) {\n",
       "    var result = [];\n",
       "    var characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';\n",
       "    var charactersLength = characters.length;\n",
       "    for (var i = 0; i < length; i++) {\n",
       "        result.push(characters.charAt(Math.floor(Math.random() * charactersLength)));\n",
       "    }\n",
       "    return result.join('');\n",
       "}\n",
       "\n",
       "// Choose a random subset of an array. Can also be used to shuffle the array\n",
       "function getRandomSubarray(arr, size) {\n",
       "    var shuffled = arr.slice(0), i = arr.length, temp, index;\n",
       "    while (i--) {\n",
       "        index = Math.floor((i + 1) * Math.random());\n",
       "        temp = shuffled[index];\n",
       "        shuffled[index] = shuffled[i];\n",
       "        shuffled[i] = temp;\n",
       "    }\n",
       "    return shuffled.slice(0, size);\n",
       "}\n",
       "\n",
       "function printResponses(responsesContainer) {\n",
       "    var responses=JSON.parse(responsesContainer.dataset.responses);\n",
       "    var stringResponses='<B>IMPORTANT!</B>To preserve this answer sequence for submission, when you have finalized your answers: <ol> <li> Copy the text in this cell below \"Answer String\"</li> <li> Double click on the cell directly below the Answer String, labeled \"Replace Me\"</li> <li> Select the whole \"Replace Me\" text</li> <li> Paste in your answer string and press shift-Enter.</li><li>Save the notebook using the save icon or File->Save Notebook menu item</li></ul><br><br><br><b>Answer String:</b><br> ';\n",
       "    console.log(responses);\n",
       "    responses.forEach((response, index) => {\n",
       "        if (response) {\n",
       "            console.log(index + ': ' + response);\n",
       "            stringResponses+= index + ': ' + response +\"<BR>\";\n",
       "        }\n",
       "    });\n",
       "    responsesContainer.innerHTML=stringResponses;\n",
       "}\n",
       "function check_mc() {\n",
       "    var id = this.id.split('-')[0];\n",
       "    //var response = this.id.split('-')[1];\n",
       "    //console.log(response);\n",
       "    //console.log(\"In check_mc(), id=\"+id);\n",
       "    //console.log(event.srcElement.id)           \n",
       "    //console.log(event.srcElement.dataset.correct)   \n",
       "    //console.log(event.srcElement.dataset.feedback)\n",
       "\n",
       "    var label = event.srcElement;\n",
       "    //console.log(label, label.nodeName);\n",
       "    var depth = 0;\n",
       "    while ((label.nodeName != \"LABEL\") && (depth < 20)) {\n",
       "        label = label.parentElement;\n",
       "        console.log(depth, label);\n",
       "        depth++;\n",
       "    }\n",
       "\n",
       "\n",
       "\n",
       "    var answers = label.parentElement.children;\n",
       "\n",
       "    //console.log(answers);\n",
       "\n",
       "\n",
       "    // Split behavior based on multiple choice vs many choice:\n",
       "    var fb = document.getElementById(\"fb\" + id);\n",
       "\n",
       "\n",
       "\n",
       "\n",
       "    if (fb.dataset.numcorrect == 1) {\n",
       "        // What follows is for the saved responses stuff\n",
       "        var outerContainer = fb.parentElement.parentElement;\n",
       "        var responsesContainer = document.getElementById(\"responses\" + outerContainer.id);\n",
       "        if (responsesContainer) {\n",
       "            //console.log(responsesContainer);\n",
       "            var response = label.firstChild.innerText;\n",
       "            if (label.querySelector(\".QuizCode\")){\n",
       "                response+= label.querySelector(\".QuizCode\").firstChild.innerText;\n",
       "            }\n",
       "            console.log(response);\n",
       "            //console.log(document.getElementById(\"quizWrap\"+id));\n",
       "            var qnum = document.getElementById(\"quizWrap\"+id).dataset.qnum;\n",
       "            console.log(\"Question \" + qnum);\n",
       "            //console.log(id, \", got numcorrect=\",fb.dataset.numcorrect);\n",
       "            var responses=JSON.parse(responsesContainer.dataset.responses);\n",
       "            console.log(responses);\n",
       "            responses[qnum]= response;\n",
       "            responsesContainer.setAttribute('data-responses', JSON.stringify(responses));\n",
       "            printResponses(responsesContainer);\n",
       "        }\n",
       "        // End code to preserve responses\n",
       "        \n",
       "        for (var i = 0; i < answers.length; i++) {\n",
       "            var child = answers[i];\n",
       "            //console.log(child);\n",
       "            child.className = \"MCButton\";\n",
       "        }\n",
       "\n",
       "\n",
       "\n",
       "        if (label.dataset.correct == \"true\") {\n",
       "            // console.log(\"Correct action\");\n",
       "            if (\"feedback\" in label.dataset) {\n",
       "                fb.textContent = jaxify(label.dataset.feedback);\n",
       "            } else {\n",
       "                fb.textContent = \"Correct!\";\n",
       "            }\n",
       "            label.classList.add(\"correctButton\");\n",
       "\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"correct\");\n",
       "\n",
       "        } else {\n",
       "            if (\"feedback\" in label.dataset) {\n",
       "                fb.textContent = jaxify(label.dataset.feedback);\n",
       "            } else {\n",
       "                fb.textContent = \"Incorrect -- try again.\";\n",
       "            }\n",
       "            //console.log(\"Error action\");\n",
       "            label.classList.add(\"incorrectButton\");\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"incorrect\");\n",
       "        }\n",
       "    }\n",
       "    else {\n",
       "        var reset = false;\n",
       "        var feedback;\n",
       "         if (label.dataset.correct == \"true\") {\n",
       "            if (\"feedback\" in label.dataset) {\n",
       "                feedback = jaxify(label.dataset.feedback);\n",
       "            } else {\n",
       "                feedback = \"Correct!\";\n",
       "            }\n",
       "            if (label.dataset.answered <= 0) {\n",
       "                if (fb.dataset.answeredcorrect < 0) {\n",
       "                    fb.dataset.answeredcorrect = 1;\n",
       "                    reset = true;\n",
       "                } else {\n",
       "                    fb.dataset.answeredcorrect++;\n",
       "                }\n",
       "                if (reset) {\n",
       "                    for (var i = 0; i < answers.length; i++) {\n",
       "                        var child = answers[i];\n",
       "                        child.className = \"MCButton\";\n",
       "                        child.dataset.answered = 0;\n",
       "                    }\n",
       "                }\n",
       "                label.classList.add(\"correctButton\");\n",
       "                label.dataset.answered = 1;\n",
       "                fb.className = \"Feedback\";\n",
       "                fb.classList.add(\"correct\");\n",
       "\n",
       "            }\n",
       "        } else {\n",
       "            if (\"feedback\" in label.dataset) {\n",
       "                feedback = jaxify(label.dataset.feedback);\n",
       "            } else {\n",
       "                feedback = \"Incorrect -- try again.\";\n",
       "            }\n",
       "            if (fb.dataset.answeredcorrect > 0) {\n",
       "                fb.dataset.answeredcorrect = -1;\n",
       "                reset = true;\n",
       "            } else {\n",
       "                fb.dataset.answeredcorrect--;\n",
       "            }\n",
       "\n",
       "            if (reset) {\n",
       "                for (var i = 0; i < answers.length; i++) {\n",
       "                    var child = answers[i];\n",
       "                    child.className = \"MCButton\";\n",
       "                    child.dataset.answered = 0;\n",
       "                }\n",
       "            }\n",
       "            label.classList.add(\"incorrectButton\");\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"incorrect\");\n",
       "        }\n",
       "        // What follows is for the saved responses stuff\n",
       "        var outerContainer = fb.parentElement.parentElement;\n",
       "        var responsesContainer = document.getElementById(\"responses\" + outerContainer.id);\n",
       "        if (responsesContainer) {\n",
       "            //console.log(responsesContainer);\n",
       "            var response = label.firstChild.innerText;\n",
       "            if (label.querySelector(\".QuizCode\")){\n",
       "                response+= label.querySelector(\".QuizCode\").firstChild.innerText;\n",
       "            }\n",
       "            console.log(response);\n",
       "            //console.log(document.getElementById(\"quizWrap\"+id));\n",
       "            var qnum = document.getElementById(\"quizWrap\"+id).dataset.qnum;\n",
       "            console.log(\"Question \" + qnum);\n",
       "            //console.log(id, \", got numcorrect=\",fb.dataset.numcorrect);\n",
       "            var responses=JSON.parse(responsesContainer.dataset.responses);\n",
       "            if (label.dataset.correct == \"true\") {\n",
       "                if (typeof(responses[qnum]) == \"object\"){\n",
       "                    if (!responses[qnum].includes(response))\n",
       "                        responses[qnum].push(response);\n",
       "                } else{\n",
       "                    responses[qnum]= [ response ];\n",
       "                }\n",
       "            } else {\n",
       "                responses[qnum]= response;\n",
       "            }\n",
       "            console.log(responses);\n",
       "            responsesContainer.setAttribute('data-responses', JSON.stringify(responses));\n",
       "            printResponses(responsesContainer);\n",
       "        }\n",
       "        // End save responses stuff\n",
       "\n",
       "\n",
       "\n",
       "        var numcorrect = fb.dataset.numcorrect;\n",
       "        var answeredcorrect = fb.dataset.answeredcorrect;\n",
       "        if (answeredcorrect >= 0) {\n",
       "            fb.textContent = feedback + \" [\" + answeredcorrect + \"/\" + numcorrect + \"]\";\n",
       "        } else {\n",
       "            fb.textContent = feedback + \" [\" + 0 + \"/\" + numcorrect + \"]\";\n",
       "        }\n",
       "\n",
       "\n",
       "    }\n",
       "\n",
       "    if (typeof MathJax != 'undefined') {\n",
       "        var version = MathJax.version;\n",
       "        console.log('MathJax version', version);\n",
       "        if (version[0] == \"2\") {\n",
       "            MathJax.Hub.Queue([\"Typeset\", MathJax.Hub]);\n",
       "        } else if (version[0] == \"3\") {\n",
       "            MathJax.typeset([fb]);\n",
       "        }\n",
       "    } else {\n",
       "        console.log('MathJax not detected');\n",
       "    }\n",
       "\n",
       "}\n",
       "\n",
       "function make_mc(qa, shuffle_answers, outerqDiv, qDiv, aDiv, id) {\n",
       "    var shuffled;\n",
       "    if (shuffle_answers == \"True\") {\n",
       "        //console.log(shuffle_answers+\" read as true\");\n",
       "        shuffled = getRandomSubarray(qa.answers, qa.answers.length);\n",
       "    } else {\n",
       "        //console.log(shuffle_answers+\" read as false\");\n",
       "        shuffled = qa.answers;\n",
       "    }\n",
       "\n",
       "\n",
       "    var num_correct = 0;\n",
       "\n",
       "\n",
       "\n",
       "    shuffled.forEach((item, index, ans_array) => {\n",
       "        //console.log(answer);\n",
       "\n",
       "        // Make input element\n",
       "        var inp = document.createElement(\"input\");\n",
       "        inp.type = \"radio\";\n",
       "        inp.id = \"quizo\" + id + index;\n",
       "        inp.style = \"display:none;\";\n",
       "        aDiv.append(inp);\n",
       "\n",
       "        //Make label for input element\n",
       "        var lab = document.createElement(\"label\");\n",
       "        lab.className = \"MCButton\";\n",
       "        lab.id = id + '-' + index;\n",
       "        lab.onclick = check_mc;\n",
       "        var aSpan = document.createElement('span');\n",
       "        aSpan.classsName = \"\";\n",
       "        //qDiv.id=\"quizQn\"+id+index;\n",
       "        if (\"answer\" in item) {\n",
       "            aSpan.innerHTML = jaxify(item.answer);\n",
       "            //aSpan.innerHTML=item.answer;\n",
       "        }\n",
       "        lab.append(aSpan);\n",
       "\n",
       "        // Create div for code inside question\n",
       "        var codeSpan;\n",
       "        if (\"code\" in item) {\n",
       "            codeSpan = document.createElement('span');\n",
       "            codeSpan.id = \"code\" + id + index;\n",
       "            codeSpan.className = \"QuizCode\";\n",
       "            var codePre = document.createElement('pre');\n",
       "            codeSpan.append(codePre);\n",
       "            var codeCode = document.createElement('code');\n",
       "            codePre.append(codeCode);\n",
       "            codeCode.innerHTML = item.code;\n",
       "            lab.append(codeSpan);\n",
       "            //console.log(codeSpan);\n",
       "        }\n",
       "\n",
       "        //lab.textContent=item.answer;\n",
       "\n",
       "        // Set the data attributes for the answer\n",
       "        lab.setAttribute('data-correct', item.correct);\n",
       "        if (item.correct) {\n",
       "            num_correct++;\n",
       "        }\n",
       "        if (\"feedback\" in item) {\n",
       "            lab.setAttribute('data-feedback', item.feedback);\n",
       "        }\n",
       "        lab.setAttribute('data-answered', 0);\n",
       "\n",
       "        aDiv.append(lab);\n",
       "\n",
       "    });\n",
       "\n",
       "    if (num_correct > 1) {\n",
       "        outerqDiv.className = \"ManyChoiceQn\";\n",
       "    } else {\n",
       "        outerqDiv.className = \"MultipleChoiceQn\";\n",
       "    }\n",
       "\n",
       "    return num_correct;\n",
       "\n",
       "}\n",
       "function check_numeric(ths, event) {\n",
       "\n",
       "    if (event.keyCode === 13) {\n",
       "        ths.blur();\n",
       "\n",
       "        var id = ths.id.split('-')[0];\n",
       "\n",
       "        var submission = ths.value;\n",
       "        if (submission.indexOf('/') != -1) {\n",
       "            var sub_parts = submission.split('/');\n",
       "            //console.log(sub_parts);\n",
       "            submission = sub_parts[0] / sub_parts[1];\n",
       "        }\n",
       "        //console.log(\"Reader entered\", submission);\n",
       "\n",
       "        if (\"precision\" in ths.dataset) {\n",
       "            var precision = ths.dataset.precision;\n",
       "            // console.log(\"1:\", submission)\n",
       "            submission = Math.round((1 * submission + Number.EPSILON) * 10 ** precision) / 10 ** precision;\n",
       "            // console.log(\"Rounded to \", submission, \" precision=\", precision  );\n",
       "        }\n",
       "\n",
       "\n",
       "        //console.log(\"In check_numeric(), id=\"+id);\n",
       "        //console.log(event.srcElement.id)           \n",
       "        //console.log(event.srcElement.dataset.feedback)\n",
       "\n",
       "        var fb = document.getElementById(\"fb\" + id);\n",
       "        fb.style.display = \"none\";\n",
       "        fb.textContent = \"Incorrect -- try again.\";\n",
       "\n",
       "        var answers = JSON.parse(ths.dataset.answers);\n",
       "        //console.log(answers);\n",
       "\n",
       "        var defaultFB = \"\";\n",
       "        var correct;\n",
       "        var done = false;\n",
       "        answers.every(answer => {\n",
       "            //console.log(answer.type);\n",
       "\n",
       "            correct = false;\n",
       "            // if (answer.type==\"value\"){\n",
       "            if ('value' in answer) {\n",
       "                if (submission == answer.value) {\n",
       "                    fb.textContent = jaxify(answer.feedback);\n",
       "                    correct = answer.correct;\n",
       "                    //console.log(answer.correct);\n",
       "                    done = true;\n",
       "                }\n",
       "                // } else if (answer.type==\"range\") {\n",
       "            } else if ('range' in answer) {\n",
       "                //console.log(answer.range);\n",
       "                if ((submission >= answer.range[0]) && (submission < answer.range[1])) {\n",
       "                    fb.textContent = jaxify(answer.feedback);\n",
       "                    correct = answer.correct;\n",
       "                    //console.log(answer.correct);\n",
       "                    done = true;\n",
       "                }\n",
       "            } else if (answer.type == \"default\") {\n",
       "                defaultFB = answer.feedback;\n",
       "            }\n",
       "            if (done) {\n",
       "                return false; // Break out of loop if this has been marked correct\n",
       "            } else {\n",
       "                return true; // Keep looking for case that includes this as a correct answer\n",
       "            }\n",
       "        });\n",
       "\n",
       "        if ((!done) && (defaultFB != \"\")) {\n",
       "            fb.innerHTML = jaxify(defaultFB);\n",
       "            //console.log(\"Default feedback\", defaultFB);\n",
       "        }\n",
       "\n",
       "        fb.style.display = \"block\";\n",
       "        if (correct) {\n",
       "            ths.className = \"Input-text\";\n",
       "            ths.classList.add(\"correctButton\");\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"correct\");\n",
       "        } else {\n",
       "            ths.className = \"Input-text\";\n",
       "            ths.classList.add(\"incorrectButton\");\n",
       "            fb.className = \"Feedback\";\n",
       "            fb.classList.add(\"incorrect\");\n",
       "        }\n",
       "\n",
       "        // What follows is for the saved responses stuff\n",
       "        var outerContainer = fb.parentElement.parentElement;\n",
       "        var responsesContainer = document.getElementById(\"responses\" + outerContainer.id);\n",
       "        if (responsesContainer) {\n",
       "            console.log(submission);\n",
       "            var qnum = document.getElementById(\"quizWrap\"+id).dataset.qnum;\n",
       "            //console.log(\"Question \" + qnum);\n",
       "            //console.log(id, \", got numcorrect=\",fb.dataset.numcorrect);\n",
       "            var responses=JSON.parse(responsesContainer.dataset.responses);\n",
       "            console.log(responses);\n",
       "            if (submission == ths.value){\n",
       "                responses[qnum]= submission;\n",
       "            } else {\n",
       "                responses[qnum]= ths.value + \"(\" + submission +\")\";\n",
       "            }\n",
       "            responsesContainer.setAttribute('data-responses', JSON.stringify(responses));\n",
       "            printResponses(responsesContainer);\n",
       "        }\n",
       "        // End code to preserve responses\n",
       "\n",
       "        if (typeof MathJax != 'undefined') {\n",
       "            var version = MathJax.version;\n",
       "            console.log('MathJax version', version);\n",
       "            if (version[0] == \"2\") {\n",
       "                MathJax.Hub.Queue([\"Typeset\", MathJax.Hub]);\n",
       "            } else if (version[0] == \"3\") {\n",
       "                MathJax.typeset([fb]);\n",
       "            }\n",
       "        } else {\n",
       "            console.log('MathJax not detected');\n",
       "        }\n",
       "        return false;\n",
       "    }\n",
       "\n",
       "}\n",
       "\n",
       "function isValid(el, charC) {\n",
       "    //console.log(\"Input char: \", charC);\n",
       "    if (charC == 46) {\n",
       "        if (el.value.indexOf('.') === -1) {\n",
       "            return true;\n",
       "        } else if (el.value.indexOf('/') != -1) {\n",
       "            var parts = el.value.split('/');\n",
       "            if (parts[1].indexOf('.') === -1) {\n",
       "                return true;\n",
       "            }\n",
       "        }\n",
       "        else {\n",
       "            return false;\n",
       "        }\n",
       "    } else if (charC == 47) {\n",
       "        if (el.value.indexOf('/') === -1) {\n",
       "            if ((el.value != \"\") && (el.value != \".\")) {\n",
       "                return true;\n",
       "            } else {\n",
       "                return false;\n",
       "            }\n",
       "        } else {\n",
       "            return false;\n",
       "        }\n",
       "    } else if (charC == 45) {\n",
       "        var edex = el.value.indexOf('e');\n",
       "        if (edex == -1) {\n",
       "            edex = el.value.indexOf('E');\n",
       "        }\n",
       "\n",
       "        if (el.value == \"\") {\n",
       "            return true;\n",
       "        } else if (edex == (el.value.length - 1)) { // If just after e or E\n",
       "            return true;\n",
       "        } else {\n",
       "            return false;\n",
       "        }\n",
       "    } else if (charC == 101) { // \"e\"\n",
       "        if ((el.value.indexOf('e') === -1) && (el.value.indexOf('E') === -1) && (el.value.indexOf('/') == -1)) {\n",
       "            // Prev symbol must be digit or decimal point:\n",
       "            if (el.value.slice(-1).search(/\\d/) >= 0) {\n",
       "                return true;\n",
       "            } else if (el.value.slice(-1).search(/\\./) >= 0) {\n",
       "                return true;\n",
       "            } else {\n",
       "                return false;\n",
       "            }\n",
       "        } else {\n",
       "            return false;\n",
       "        }\n",
       "    } else {\n",
       "        if (charC > 31 && (charC < 48 || charC > 57))\n",
       "            return false;\n",
       "    }\n",
       "    return true;\n",
       "}\n",
       "\n",
       "function numeric_keypress(evnt) {\n",
       "    var charC = (evnt.which) ? evnt.which : evnt.keyCode;\n",
       "\n",
       "    if (charC == 13) {\n",
       "        check_numeric(this, evnt);\n",
       "    } else {\n",
       "        return isValid(this, charC);\n",
       "    }\n",
       "}\n",
       "\n",
       "\n",
       "\n",
       "\n",
       "\n",
       "function make_numeric(qa, outerqDiv, qDiv, aDiv, id) {\n",
       "\n",
       "\n",
       "\n",
       "    //console.log(answer);\n",
       "\n",
       "\n",
       "    outerqDiv.className = \"NumericQn\";\n",
       "    aDiv.style.display = 'block';\n",
       "\n",
       "    var lab = document.createElement(\"label\");\n",
       "    lab.className = \"InpLabel\";\n",
       "    lab.textContent = \"Type numeric answer here:\";\n",
       "    aDiv.append(lab);\n",
       "\n",
       "    var inp = document.createElement(\"input\");\n",
       "    inp.type = \"text\";\n",
       "    //inp.id=\"input-\"+id;\n",
       "    inp.id = id + \"-0\";\n",
       "    inp.className = \"Input-text\";\n",
       "    inp.setAttribute('data-answers', JSON.stringify(qa.answers));\n",
       "    if (\"precision\" in qa) {\n",
       "        inp.setAttribute('data-precision', qa.precision);\n",
       "    }\n",
       "    aDiv.append(inp);\n",
       "    //console.log(inp);\n",
       "\n",
       "    //inp.addEventListener(\"keypress\", check_numeric);\n",
       "    //inp.addEventListener(\"keypress\", numeric_keypress);\n",
       "    /*\n",
       "    inp.addEventListener(\"keypress\", function(event) {\n",
       "        return numeric_keypress(this, event);\n",
       "    }\n",
       "                        );\n",
       "                        */\n",
       "    //inp.onkeypress=\"return numeric_keypress(this, event)\";\n",
       "    inp.onkeypress = numeric_keypress;\n",
       "    inp.onpaste = event => false;\n",
       "\n",
       "    inp.addEventListener(\"focus\", function (event) {\n",
       "        this.value = \"\";\n",
       "        return false;\n",
       "    }\n",
       "    );\n",
       "\n",
       "\n",
       "}\n",
       "function jaxify(string) {\n",
       "    var mystring = string;\n",
       "\n",
       "    var count = 0;\n",
       "    var loc = mystring.search(/([^\\\\]|^)(\\$)/);\n",
       "\n",
       "    var count2 = 0;\n",
       "    var loc2 = mystring.search(/([^\\\\]|^)(\\$\\$)/);\n",
       "\n",
       "    //console.log(loc);\n",
       "\n",
       "    while ((loc >= 0) || (loc2 >= 0)) {\n",
       "\n",
       "        /* Have to replace all the double $$ first with current implementation */\n",
       "        if (loc2 >= 0) {\n",
       "            if (count2 % 2 == 0) {\n",
       "                mystring = mystring.replace(/([^\\\\]|^)(\\$\\$)/, \"$1\\\\[\");\n",
       "            } else {\n",
       "                mystring = mystring.replace(/([^\\\\]|^)(\\$\\$)/, \"$1\\\\]\");\n",
       "            }\n",
       "            count2++;\n",
       "        } else {\n",
       "            if (count % 2 == 0) {\n",
       "                mystring = mystring.replace(/([^\\\\]|^)(\\$)/, \"$1\\\\(\");\n",
       "            } else {\n",
       "                mystring = mystring.replace(/([^\\\\]|^)(\\$)/, \"$1\\\\)\");\n",
       "            }\n",
       "            count++;\n",
       "        }\n",
       "        loc = mystring.search(/([^\\\\]|^)(\\$)/);\n",
       "        loc2 = mystring.search(/([^\\\\]|^)(\\$\\$)/);\n",
       "        //console.log(mystring,\", loc:\",loc,\", loc2:\",loc2);\n",
       "    }\n",
       "\n",
       "    //console.log(mystring);\n",
       "    return mystring;\n",
       "}\n",
       "\n",
       "\n",
       "function show_questions(json, mydiv) {\n",
       "    console.log('show_questions');\n",
       "    //var mydiv=document.getElementById(myid);\n",
       "    var shuffle_questions = mydiv.dataset.shufflequestions;\n",
       "    var num_questions = mydiv.dataset.numquestions;\n",
       "    var shuffle_answers = mydiv.dataset.shuffleanswers;\n",
       "\n",
       "    if (num_questions > json.length) {\n",
       "        num_questions = json.length;\n",
       "    }\n",
       "\n",
       "    var questions;\n",
       "    if ((num_questions < json.length) || (shuffle_questions == \"True\")) {\n",
       "        //console.log(num_questions+\",\"+json.length);\n",
       "        questions = getRandomSubarray(json, num_questions);\n",
       "    } else {\n",
       "        questions = json;\n",
       "    }\n",
       "\n",
       "    //console.log(\"SQ: \"+shuffle_questions+\", NQ: \" + num_questions + \", SA: \", shuffle_answers);\n",
       "\n",
       "    // Iterate over questions\n",
       "    questions.forEach((qa, index, array) => {\n",
       "        //console.log(qa.question); \n",
       "\n",
       "        var id = makeid(8);\n",
       "        //console.log(id);\n",
       "\n",
       "\n",
       "        // Create Div to contain question and answers\n",
       "        var iDiv = document.createElement('div');\n",
       "        //iDiv.id = 'quizWrap' + id + index;\n",
       "        iDiv.id = 'quizWrap' + id;\n",
       "        iDiv.className = 'Quiz';\n",
       "        iDiv.setAttribute('data-qnum', index);\n",
       "        mydiv.appendChild(iDiv);\n",
       "        // iDiv.innerHTML=qa.question;\n",
       "\n",
       "        var outerqDiv = document.createElement('div');\n",
       "        outerqDiv.id = \"OuterquizQn\" + id + index;\n",
       "\n",
       "        iDiv.append(outerqDiv);\n",
       "\n",
       "        // Create div to contain question part\n",
       "        var qDiv = document.createElement('div');\n",
       "        qDiv.id = \"quizQn\" + id + index;\n",
       "        //qDiv.textContent=qa.question;\n",
       "        qDiv.innerHTML = jaxify(qa.question);\n",
       "\n",
       "        outerqDiv.append(qDiv);\n",
       "\n",
       "        // Create div for code inside question\n",
       "        var codeDiv;\n",
       "        if (\"code\" in qa) {\n",
       "            codeDiv = document.createElement('div');\n",
       "            codeDiv.id = \"code\" + id + index;\n",
       "            codeDiv.className = \"QuizCode\";\n",
       "            var codePre = document.createElement('pre');\n",
       "            codeDiv.append(codePre);\n",
       "            var codeCode = document.createElement('code');\n",
       "            codePre.append(codeCode);\n",
       "            codeCode.innerHTML = qa.code;\n",
       "            outerqDiv.append(codeDiv);\n",
       "            //console.log(codeDiv);\n",
       "        }\n",
       "\n",
       "\n",
       "        // Create div to contain answer part\n",
       "        var aDiv = document.createElement('div');\n",
       "        aDiv.id = \"quizAns\" + id + index;\n",
       "        aDiv.className = 'Answer';\n",
       "        iDiv.append(aDiv);\n",
       "\n",
       "        //console.log(qa.type);\n",
       "\n",
       "        var num_correct;\n",
       "        if (qa.type == \"multiple_choice\") {\n",
       "            num_correct = make_mc(qa, shuffle_answers, outerqDiv, qDiv, aDiv, id);\n",
       "        } else if (qa.type == \"many_choice\") {\n",
       "            num_correct = make_mc(qa, shuffle_answers, outerqDiv, qDiv, aDiv, id);\n",
       "        } else if (qa.type == \"numeric\") {\n",
       "            //console.log(\"numeric\");\n",
       "            make_numeric(qa, outerqDiv, qDiv, aDiv, id);\n",
       "        }\n",
       "\n",
       "\n",
       "        //Make div for feedback\n",
       "        var fb = document.createElement(\"div\");\n",
       "        fb.id = \"fb\" + id;\n",
       "        //fb.style=\"font-size: 20px;text-align:center;\";\n",
       "        fb.className = \"Feedback\";\n",
       "        fb.setAttribute(\"data-answeredcorrect\", 0);\n",
       "        fb.setAttribute(\"data-numcorrect\", num_correct);\n",
       "        iDiv.append(fb);\n",
       "\n",
       "\n",
       "    });\n",
       "    var preserveResponses = mydiv.dataset.preserveresponses;\n",
       "    console.log(preserveResponses);\n",
       "    console.log(preserveResponses == \"true\");\n",
       "    if (preserveResponses == \"true\") {\n",
       "        console.log(preserveResponses);\n",
       "        // Create Div to contain record of answers\n",
       "        var iDiv = document.createElement('div');\n",
       "        iDiv.id = 'responses' + mydiv.id;\n",
       "        iDiv.className = 'JCResponses';\n",
       "        // Create a place to store responses as an empty array\n",
       "        iDiv.setAttribute('data-responses', '[]');\n",
       "\n",
       "        // Dummy Text\n",
       "        iDiv.innerHTML=\"<b>Select your answers and then follow the directions that will appear here.</b>\"\n",
       "        //iDiv.className = 'Quiz';\n",
       "        mydiv.appendChild(iDiv);\n",
       "    }\n",
       "//console.log(\"At end of show_questions\");\n",
       "    if (typeof MathJax != 'undefined') {\n",
       "        console.log(\"MathJax version\", MathJax.version);\n",
       "        var version = MathJax.version;\n",
       "        setTimeout(function(){\n",
       "            var version = MathJax.version;\n",
       "            console.log('After sleep, MathJax version', version);\n",
       "            if (version[0] == \"2\") {\n",
       "                MathJax.Hub.Queue([\"Typeset\", MathJax.Hub]);\n",
       "            } else if (version[0] == \"3\") {\n",
       "                MathJax.typeset([mydiv]);\n",
       "            }\n",
       "        }, 500);\n",
       "if (typeof version == 'undefined') {\n",
       "        } else\n",
       "        {\n",
       "            if (version[0] == \"2\") {\n",
       "                MathJax.Hub.Queue([\"Typeset\", MathJax.Hub]);\n",
       "            } else if (version[0] == \"3\") {\n",
       "                MathJax.typeset([mydiv]);\n",
       "            } else {\n",
       "                console.log(\"MathJax not found\");\n",
       "            }\n",
       "        }\n",
       "    }\n",
       "    return false;\n",
       "}\n",
       "\n",
       "        {\n",
       "        show_questions(questionsVkmOpExFoYfs,  VkmOpExFoYfs);\n",
       "        }\n",
       "        "
      ],
      "text/plain": [
       "<IPython.core.display.Javascript object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "display_quiz(question_path+\"questions23.json\")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "43e5dacc",
   "metadata": {
    "kernel": "OCaml 4.13"
   },
   "source": [
    "3. Once you update the file ``simp.mll``, reset the kernel: first choose in the menu Kernel -> Restart & Clear Output to ensure your changed file is used.\n",
    "\n",
    "Let's test a final program: "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "id": "d0d384c7",
   "metadata": {
    "kernel": "OCaml 4.13"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "val p : string =\n",
       "  \"VAR s;\\nVAR n;\\ns := 0; \\nINPUT n;\\nWHILE n := 0 DO \\n    s := s + n; \\n    INPUT n\\nEND;\\nPRINT s\\n\"\n"
      ]
     },
     "execution_count": 20,
     "metadata": {},
     "output_type": "execute_result"
    },
    {
     "data": {
      "text/plain": [
       "val res : Simp.token list =\n",
       "  [Simp.VAR; Simp.ID \"s\"; Simp.SEMI; Simp.VAR; Simp.ID \"n\"; Simp.SEMI;\n",
       "   Simp.ID \"s\"; Simp.ASGN; Simp.INT 0; Simp.SEMI; Simp.INPUT; Simp.ID \"n\";\n",
       "   Simp.SEMI; Simp.WHILE; Simp.ID \"n\"; Simp.ASGN; Simp.INT 0; Simp.DO;\n",
       "   Simp.ID \"s\"; Simp.ASGN; Simp.ID \"s\"; Simp.PLUS; Simp.ID \"n\"; Simp.SEMI;\n",
       "   Simp.INPUT; Simp.ID \"n\"; Simp.END; Simp.SEMI; Simp.PRINT; Simp.ID \"s\"]\n"
      ]
     },
     "execution_count": 20,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "let p = \"VAR s;\n",
    "VAR n;\n",
    "s := 0; \n",
    "INPUT n;\n",
    "WHILE n := 0 DO \n",
    "    s := s + n; \n",
    "    INPUT n\n",
    "END;\n",
    "PRINT s\n",
    "\"\n",
    "\n",
    "let res = stream_to_list (Lexing.from_string p)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "e91ef41a",
   "metadata": {
    "kernel": "SoS"
   },
   "source": [
    "## Challenge \n",
    "\n",
    "Extend the lexer file for ``Simp`` so that comments recognized. \n",
    "\n",
    "1. Implement one-line comments, starting with ``#`` and going for the rest of the line. \n",
    " E.g., \n",
    "  ```\n",
    "  # This is a comment \n",
    "   2 + 3\n",
    "  ```\n",
    "would yield ``[INT 2; PLUS; INT 3]``.\n",
    "\n",
    "2. Implement comments going over several lines. Comments start with ``{``, end with ``}`` and ignore all content. \n",
    "    I.e., there are no nested comments. \n",
    " \n",
    " E.g., \n",
    "  ```\n",
    "  { This is a comment \n",
    "      of several lines. }\n",
    "   2 + 3\n",
    "   { Comment at the end of the file. }\n",
    "  ```\n",
    "would yield ``[INT 2; PLUS; INT 3]``.    \n",
    "    \n",
    "\n",
    "3. Can you define nested comments?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "id": "ee923a0e",
   "metadata": {
    "kernel": "OCaml 4.13"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "val p : string =\n",
       "  \"# Comment 1\\nVAR s;\\nVAR n;\\n{ Comment over several \\nlines }\\ns := 0; \\nINPUT n;\\nWHILE n := 0 DO \\n    s := s + n; \\n    INPUT n\\nEND;\\nPRINT s\\n{ Second comment. }\\n\"\n"
      ]
     },
     "execution_count": 22,
     "metadata": {},
     "output_type": "execute_result"
    },
    {
     "data": {
      "text/plain": [
       "val res : Simp.token list =\n",
       "  [Simp.VAR; Simp.ID \"s\"; Simp.SEMI; Simp.VAR; Simp.ID \"n\"; Simp.SEMI;\n",
       "   Simp.ID \"s\"; Simp.ASGN; Simp.INT 0; Simp.SEMI; Simp.INPUT; Simp.ID \"n\";\n",
       "   Simp.SEMI; Simp.WHILE; Simp.ID \"n\"; Simp.ASGN; Simp.INT 0; Simp.DO;\n",
       "   Simp.ID \"s\"; Simp.ASGN; Simp.ID \"s\"; Simp.PLUS; Simp.ID \"n\"; Simp.SEMI;\n",
       "   Simp.INPUT; Simp.ID \"n\"; Simp.END; Simp.SEMI; Simp.PRINT; Simp.ID \"s\"]\n"
      ]
     },
     "execution_count": 22,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "let p = \"# Comment 1\n",
    "VAR s;\n",
    "VAR n;\n",
    "{ Comment over several \n",
    "lines }\n",
    "s := 0; \n",
    "INPUT n;\n",
    "WHILE n := 0 DO \n",
    "    s := s + n; \n",
    "    INPUT n\n",
    "END;\n",
    "PRINT s\n",
    "{ Second comment. }\n",
    "\"\n",
    "\n",
    "let res = stream_to_list (Lexing.from_string p)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "96a83231",
   "metadata": {
    "kernel": "OCaml 4.13"
   },
   "outputs": [],
   "source": []
  }
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