Function isModifierKey

mini-code-editor/cm/lib/codemirror.js:2115–2118

(event)

    return lookup(map);
  }
  function isModifierKey(event) {
    var name = keyNames[e_prop(event, "keyCode")];
    return name == "Ctrl" || name == "Alt" || name == "Shift" || name == "Mod";
  }

  CodeMirror.fromTextArea = function(textarea, options) {
    if (!options) options = {};