zio.macros.AccessibleMMacroBase.scala Maven / Gradle / Ivy
/*
* Copyright 2019-2024 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.macros
import scala.annotation.nowarn
import scala.reflect.macros.whitebox
private[macros] abstract class AccessibleMMacroBase(override val c: whitebox.Context) extends AccessibleMacroBase(c) {
import c.universe._
protected def expectedTypeParams: Long
protected def aliases: Seq[Tree]
@nowarn("msg=pattern var [^\\s]+ in method unapply is never used")
protected val tp: Tree = c.prefix.tree match {
case q"new ${macroNm: Ident}[$typeParam]" if macroNm.name == TypeName(macroName) =>
typeParam
case _ =>
abort("could not unquote annotation. Make sure you have specified the type parameter.")
}
protected val tpTpe: Type = {
val res = c.typecheck(tq"$tp", c.TYPEmode).tpe
if (types.keySet.contains(res))
res
else
abort(s"unsupported type constructor $res. Supported constructors: ${types.keySet}")
}
private lazy val types: Map[Type, Tree] =
aliases.map(a => c.typecheck(tq"$a", c.TYPEmode).tpe -> a).toMap
@nowarn("msg=pattern var [^\\s]+ in method unapply is never used")
protected def macroApply(annottees: Seq[c.Tree]): MacroApply = new MacroApply(annottees) {
private val typeParamToInject = {
val candidates =
moduleInfo.serviceTypeParams.filter(tp => tp.tparams.size == expectedTypeParams)
candidates match {
case Seq(c) => c
case Seq() => abort(s"`Service` doesn't have type param for [$tpTpe]")
case nonEmpty => abort(s"`Service` contains several possible candidates for [$tpTpe]: $nonEmpty")
}
}
protected def treeTpe(tree: Tree): Type =
tree match {
case tq"${typeName: Ident}[..${typeParams}]" =>
val typeArgs = typeParams.map(p => c.typecheck(tq"$p", c.TYPEmode, silent = true).tpe)
val shouldInject = typeName.name == typeParamToInject.name
val injectedTypeName =
if (shouldInject) types(tpTpe)
else typeName
c.typecheck(tq"$injectedTypeName[..$typeArgs]", c.TYPEmode).tpe
case _ => abort(s"could not unquote return type tree $tree")
}
override protected def typeArgsForService(serviceTypeParams: List[TypeDef]): List[TypeName] =
serviceTypeParams.map {
case `typeParamToInject` => TypeName(tp.toString)
case other => other.name
}
override protected def typeParamsForAccessors(serviceTypeParams: List[TypeDef]): List[TypeDef] =
serviceTypeParams.filterNot(_ == typeParamToInject)
}
}