tempdsl

ExpressionList
  = e:Expression*
  
Expression
  = ae:AssignExpression
  / we:WatchExpression
  
AssignExpression
  = id: Identifier f: Factory "(" (params:ParameterList)? ")"
  
ParameterList
  = DomElement
  / EventType
  / ArrowFunction
  
ArrowFunction
  

EventType
  = "click"
  / "tap"
  / "keyup"
  / "keydown"
  / "mouseenter"
  / "mouseleave"
  
Factory
  = "fromEvent"
  / "merge"

ReservedWord
  = EventType
  / Factory
  
Identifier
  = !ReservedWord head:[a-zA-z_$] tails:[a-zA-z0-9_$]* _ {
    var ret = [head];
    tails.forEach(function (item) {
      ret.push(item);
    });
    return {
      type: "Identifier",
      name: ret.join('')
    }
  }