Scala/Lift Mapper - unsigned MappedInt

Question

是否可以在Lift中定義一個無符號映射整數？我找不到任何關於它的事情。

class Project extends LongKeyedMapper[Project] with IdPK { 
    def getSingleton = Project 
    ... 
    object budget extends MappedInt(this) // should be unsigned! 
    ... 
} 

Answer 1

由於scala或java中沒有未經過簽名的整數，所以您只需編寫一個運行時檢查。像這樣的東西應該這樣做:(沒有測試過）

object budget extends MappedInt(this) { 
    override def validations = { 
    ((value:Int) => 
     if (value < 0) 
     FieldError(fieldOwner, Text("Budget must not be negative"))::Nil 
     else 
     Nil) 
    :: super.validations 
    } 
}