微型的javascript REPL

REPL(Read Eval Print Loop)是一種非常有用的工具，能讓我們即時運行代碼得到結果。雖然相比於firebug的控制台來說，這簡直不值一提，但在個人部落格中提供示範時它還是比較有用。

下面是它的所有代碼，包括html。

<textarea style="width:100%" onkeyup="  this.rows=(function(t){    for (var i=0,h=1;i<t.length;i++) if (t.charAt(i) == '\n') h++;    return h;  })(this.value);">//---------------------這是樣本-----var now = new Date;var pad = function(num,  digits, radix, filling){     num = num.toString(radix || 10);     filling = filling || "0";     while(num.length //---------------------這是樣本-----var now = new Date;var pad = function(num,  digits, radix, filling){     num = num.toString(radix || 10);     filling = filling || "0";     while(num.length <input type="button" value="Eval" onclick="  try{    var o = this.nextSibling.nextSibling;    var p = function(s){      var e = document.createElement('p');      e.appendChild(document.createTextNode(s));      e.style.margin=0;      o.appendChild(e);    };    (new Function('p',this.previousSibling.value))(p);  }catch(e){    alert(e)  }"><input type="button" value="Clear" onclick="  this.nextSibling.innerHTML=''">