Function stative

MathBox/mathbox-bundle.js:80128–80147

()

  // stative ----------------------------

  function stative() {
    var steps = [].slice.call(arguments)
      , step
      , result

    return function() {
      var current = state[0]

      current.stage || (current.stage = 0)

      step = steps[current.stage]
      if(!step) return unexpected('parser in undefined state!')

      result = step()

      if(result === Advance) return ++current.stage
      if(result === undefined) return
      current.stage = result
    } 
  }

  function advance(op, t) {
    t = t || 'operator'