Function pattern

static/editor.md/lib/codemirror/mode/javascript/javascript.js:491–495

(type, value)

    return pass(pattern, maybetype, maybeAssign, vardefCont);
  }
  function pattern(type, value) {
    if (type == "variable") { register(value); return cont(); }
    if (type == "[") return contCommasep(pattern, "]");
    if (type == "{") return contCommasep(proppattern, "}");
  }
  function proppattern(type, value) {
    if (type == "variable" && !cx.stream.match(/^\s*:/, false)) {
      register(value);