Fire JS Bin - ZenCalculator

String.prototype.trim = function () {
  return this.replace(/^\s*/, "").replace(/\s*$/, "");
}

$(function () {

var current = 1;
  var hist = [];
  var histpos = 0;

function load() {
    hist = JSON.parse(localStorage.hist);
  }

function save() {
    localStorage.hist = JSON.stringify(hist);
    localStorage.histpos = histpos;
    localStorage.current = current;
  }

function clear() {
    current = 1;
    hist = [];
    histpos = 0;
    $("#out-inner").html('');

localStorage.clear();
  }

math = ['abs', 'acos', 'asin', 'atan', 'atan2', 'ceil', 'cos', 'exp', 'floor', 'log', 'max', 'min', 'pow', 'random', 'round', 'sin', 'sqrt', 'tan'];
  for (f in math)
  eval('var ' + math[f] + " = Math." + math[f]);

var pi = Math.PI;
  var e = Math.E;
  var ln = log;

if (localStorage.hist != undefined) {
 load();
 for (var i = 0; i < hist.length; ++i) {
 got(hist[i]);
 }
 }

function htmlify(str) {
 return str.replace(/&/g, '&').replace(/</g, '<').replace(/>/g, '>');
 }

function scrollToEnd() {
    $("#out-scroll").scrollTop($("#out-inner").height());
  }

function echo(msg) {
 $("#out-inner").append("" + htmlify(msg.toString()) + " ");
 scrollToEnd();
 }

function message(msg) {
 $("#out-inner").append((msg.toString()) + " ");
 scrollToEnd();
 }

function beautify(s) {
    s = s.replace(/(\W|^)pi(\W|$)/g, '$1π$2').replace(/\*/g, '×').replace(/-/g, '−');

return s;
  }

// Handle a lineful.

save();
  }

var funRegex = /^ *([a-zA-Z$_][a-zA-Z0-9$_]*) *$ *([a-zA-Z$_][a-zA-Z0-9$_]*) *$ *= *(.+)/;

function isFunction(what) {
    return what.match(funRegex);
  }

function handleFunction(what) {
    return what.replace(funRegex, "$1 = function($2) { return $3 }");
  }

function insert(resultIndex, formula, result) {
 var nice = htmlify(beautify(formula));
 var resultOrNothing = result != undefined ? " = " + result + "" : "";
 $("#out-inner").append("<div class='left'>r" + resultIndex + " = </div><div class='result'>" + nice + "" + resultOrNothing + "</div>");

scrollToEnd();
  }

function compute(expr) {
    var hex = expr.match(/in hex$/);
    if (hex) expr = expr.replace(/in hex$/, '');
    var oct = expr.match(/in oct$/);
    if (oct) expr = expr.replace(/in oct$/, '');

echo(expr);
    var expr = expr.replace(/(\d)deg([^a-zA-Z0-9$_]|$)/, '$1 * (2 * pi / 360)$2');
    var actualExpr = handleFunction(expr);
    try {
      currentVar = "r" + current;
      var result = eval(currentVar + "=" + actualExpr);

if (abs(result) < 2.5e-16) {
 result = 0;
 }
 } catch (err) {
 message(err + ". (Terribly sorry, milady, sir.)");
 return;
 }

if (isFunction(expr)) insert(current, expr);
    else {
      if (hex) result = "0x" + result.toString(16);
      if (oct) result = "0" + result.toString(8);

insert(current, expr, result);
    }

++current;
  }

$('#in input').keydown(function (e) {
    var it = $(this);
    var code = e.keyCode ? e.keyCode : e.which;
    var what = it.attr('value');

if (code == 13) {
 it.attr('value', '');
 histpos = hist.push(what);
 got(what);
 } else if (code == 38) {
 if (histpos > 0)--histpos;
 it.attr('value', hist[histpos]);
 } else if (code == 40) {
 if (histpos < hist.length - 1)++histpos;
 it.attr('value', hist[histpos]);
 } else if (code == 9) {} else {
 return true;
 }

return false;
  });

function focus() {
    $('input').focus();
  }

function onResize() {
    var viewportHeight = $(window).height();
    var quantized = Math.floor(viewportHeight / 20) * 20;
    $('#out-scroll').css('max-height', quantized - 100 + "px");
    scrollToEnd();
  }
  $(window).resize(onResize);
  onResize();

focus();

message("Welcome, milady, esteemed sir. Please enter your calculation.");
 message("Type ‘help’ to get instructions.");
});

html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, font, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td { margin:0; padding:0; border:0; outline:0; font-size:100%; vertical-align:baseline; background:transparent; }
body { line-height:1; }
ol, ul { list-style:none; }
blockquote, q { quotes:none; }
blockquote:before { content:''; content:none; }
blockquote:after { content:''; content:none; }
q:before { content:''; content:none; }
q:after { content:''; content:none; }
:focus { outline:0; }
ins { text-decoration:none; }
del { text-decoration:line-through; }
table { border-collapse:collapse; border-spacing:0; }
* { font-family:myriad-pro-1, myriad-pro-2, "Helvetica Neue", sans-serif; font-weight:300; font-size:16px; }
body { background:white; width:640px; margin:20px auto; border:1px solid #cccccc; line-height:20px; }
#out { padding:20px 0 0 0; }
#out-scroll { max-height:240px; overflow:auto; }
#out-inner { margin-left:60px; margin-right:20px; }
.left { float:left; width:56px; margin-left:-60px; text-align:right; color:#888888; }
.echo { color:#888888; }
#in { background:#ffffd4; margin-bottom:20px; }
#in .left { margin-left:0; width:58px; margin-right:1px; }
input { border:none; background-color:transparent; margin:0; padding:0; outline:none; width:540px; }
span.result { color:black; }
span.result.final { color:green; }
span.op, span.var { cursor:pointer; }
span.var { color:black; }
span.var.new, b { font-weight:600; }
::-moz-selection { background:#cfcfcf; }
::selection { background:#cfcfce; }
::-webkit-selection { background:#cfcecf; }
.f, .m { display: none; }