val queryParams = Map( ("keyword" -> "k"), ("from" -> "f"), ("to" -> "t"), ("limit" -> "l") )

def someMethod( keyword: String, from: String, to: String, limit: String) = { //do something with input params }

someMethod( queryParams.get("keyword").getOrElse(""), queryParams.get("from").getOrElse(""), queryParams.get("to").getOrElse(""), queryParams.get("limit").getOrElse(""))