zio.json.JsonFieldDecoder.scala Maven / Gradle / Ivy
/*
* Copyright 2019-2022 John A. De Goes and the ZIO Contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package zio.json
/** When decoding a JSON Object, we only allow the keys that implement this interface. */
trait JsonFieldDecoder[+A] {
self =>
final def map[B](f: A => B): JsonFieldDecoder[B] =
new JsonFieldDecoder[B] {
def unsafeDecodeField(trace: List[JsonError], in: String): B =
f(self.unsafeDecodeField(trace, in))
}
final def mapOrFail[B](f: A => Either[String, B]): JsonFieldDecoder[B] =
new JsonFieldDecoder[B] {
def unsafeDecodeField(trace: List[JsonError], in: String): B =
f(self.unsafeDecodeField(trace, in)) match {
case Left(err) =>
throw JsonDecoder.UnsafeJson(JsonError.Message(err) :: trace)
case Right(b) => b
}
}
def unsafeDecodeField(trace: List[JsonError], in: String): A
}
object JsonFieldDecoder {
def apply[A](implicit a: JsonFieldDecoder[A]): JsonFieldDecoder[A] = a
implicit val string: JsonFieldDecoder[String] = new JsonFieldDecoder[String] {
def unsafeDecodeField(trace: List[JsonError], in: String): String = in
}
implicit val int: JsonFieldDecoder[Int] =
JsonFieldDecoder[String].mapOrFail { str =>
try {
Right(str.toInt)
} catch {
case n: NumberFormatException => Left(s"Invalid Int: '$str': $n")
}
}
implicit val long: JsonFieldDecoder[Long] =
JsonFieldDecoder[String].mapOrFail { str =>
try {
Right(str.toLong)
} catch {
case n: NumberFormatException => Left(s"Invalid Long: '$str': $n")
}
}
}