testCode = 'svar num = 2 + 10;\nprint num;\nsvar str = "test: ";\nprint str + num;'; function interpret(code) { document.getElementById("output").innerHTML = ""; lines = code.split(";"); for(var i=0; i";}`; result = 'try {\n'+lines.join("")+'\n}\ncatch(err) {error(err, err.stack.replace(/^(.|\\n)*?:(\\d+)(.|\\n)*$/, function (match, p1, p2) {return((+p2)-1);}));}'+printStr; var script = document.createElement("script"); script.innerHTML = result; document.head.appendChild(script); } function syntax(code) { result = code .replace(/([^\w]|^)([\d\.]+)(?=[^\w]|$)/g, "$1{'num'{$2}}") .replace(/(".*?")/g, "{'str'{$1}}") //.replace(/(\=|\+|\-|\*|\/)/g, "{'math'{$1}}") .replace(/(\s|\n|^)(svar|print)(\s|;)/g, "$1{'term'{$2}}$3") .replace(/\{'str'\{(.*)\}\}/g, remove) .replace(/\{'(.*?)'\{(.*?)\}\}/g, "$2") .replace(/\n/g, "
")+"
"; document.getElementById("code").innerHTML = result; } function remove (match, p1) { var res = p1; while (res.match(/\{'.*?'\{.*?\}\}/g)) { res = res.replace(/\{'.*?'\{(.*?)\}\}/g, '$1'); } return "{'str'{" + res + "}}"; } window.addEventListener("DOMContentLoaded", function () { document.getElementById('input').value = testCode; syntax(testCode); handleScroll (); document.getElementById('input').addEventListener('input', (e)=>{ syntax(e.currentTarget.value); }); document.getElementById('interpret').addEventListener('click', ()=>{ interpret(document.getElementById('input').value); }); document.getElementById('input').addEventListener('scroll', (e)=>{ handleScroll() }); }); function handleScroll() { var el = document.getElementById('input'); var target = document.getElementById('code'); target.scrollTop = el.scrollTop; } function print(txt) { document.getElementById("output").innerHTML += txt + "
"; } function error(txt, line) { console.log(line) print('' + txt + '
Line: ' + line + '') }

JS Interpreter[EDITOR](CONTEST)