问题描述
在某些情况下，对于案例类，默认值比可选参数有意义:
In some cases default values make more sense than optionals in case classes:
case class Car(numberOfWheels:Int = 4, color:String)
case class Car(numbeOfWheels:Option[Int], color:String) //silly
在第一种情况下，我希望能够轻松地将以下json转换为实例:
In the first case I'd expect to be able to easily convert the following json to an instance:
{"color":"red"}
但是对于标准的jsonFormat2(Car)，spray-json抱怨numberOfWheels的值缺失.
But with a standard jsonFormat2(Car), spray-json complains about missing value for numberOfWheels.
我如何最干净地解决这个问题?
How do I work around this most cleanly?
推荐答案
我偶然发现了同样的问题.我已经创建了一个补丁来为我解决.它使具有默认值的字段为可选.
I stumbled upon the same problem. I've create a patch that solves it for me. It makes fields with a default value optional.
https://github.com/spray/spray-json/pull/56
更新:PR已更新，并且仍打开 https://github.com/spray/spray-json/pull/93
update: PR is updated and still open https://github.com/spray/spray-json/pull/93
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