datomisca.AsPermanentEntityId.scala Maven / Gradle / Ivy
/*
* Copyright 2012 Pellucid and Zenexity
*
* 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 datomisca
import scala.annotation.implicitNotFound
/** A conversion type class for permanent entity ids.
*
* A type class for converting from the various types
* that can be used as permanent entity ids.
*
* @tparam T
* the type of the id to convert.
*/
@implicitNotFound("Cannot convert value of type ${T} to a permanent Datomic entity id")
sealed trait AsPermanentEntityId[T] {
protected[datomisca] def conv(t: T): AnyRef
}
/** The instances of the [[AsPermanentEntityId]] type class. */
object AsPermanentEntityId {
/** Any type viewable as a Long can be a permanent entity id. */
implicit def long[L](implicit toLong: L => Long): AsPermanentEntityId[L] =
new AsPermanentEntityId[L] {
override protected[datomisca] def conv(l: L) = toLong(l): java.lang.Long
}
/** A [[FinalId]] can be a permament entity id. */
implicit val finalid: AsPermanentEntityId[FinalId] =
new AsPermanentEntityId[FinalId] {
override protected[datomisca] def conv(l: FinalId) = l.underlying: java.lang.Long
}
/** A [[LookupRef]] can be a permament entity id. */
implicit def lookupRefId: AsPermanentEntityId[LookupRef] =
new AsPermanentEntityId[LookupRef] {
override protected[datomisca] def conv(l: LookupRef) = l.toDatomicId
}
}