diff options
Diffstat (limited to 'core/shared/src/main/scala/magnolia.scala')
| -rw-r--r-- | core/shared/src/main/scala/magnolia.scala | 83 |
1 files changed, 45 insertions, 38 deletions
diff --git a/core/shared/src/main/scala/magnolia.scala b/core/shared/src/main/scala/magnolia.scala index 6400002..0e5728c 100644 --- a/core/shared/src/main/scala/magnolia.scala +++ b/core/shared/src/main/scala/magnolia.scala @@ -81,41 +81,44 @@ object Magnolia { else q"${tpe.typeSymbol.name.toTermName}" } - val typeDefs = prefixType.baseClasses.flatMap { cls => - cls.asType.toType.decls.filter(_.isType).find(_.name.toString == "Typeclass").map { tpe => - tpe.asType.toType.asSeenFrom(prefixType, cls) + + def getTypeMember(name: String) = { + val typeDefs = prefixType.baseClasses.flatMap { cls => + cls.asType.toType.decls.filter(_.isType).find(_.name.toString == name).map { tpe => + tpe.asType.toType.asSeenFrom(prefixType, cls) + } } - } - val typeConstructorOpt = - typeDefs.headOption.map(_.typeConstructor) + val typeConstructorOpt = typeDefs.headOption.map(_.typeConstructor) - val typeConstructor = typeConstructorOpt.getOrElse { - c.abort(c.enclosingPosition, - "magnolia: the derivation object does not define the Typeclass type constructor") + typeConstructorOpt.getOrElse { + c.abort(c.enclosingPosition, + s"magnolia: the derivation object does not define the $name type constructor") + } } - def checkMethod(termName: String, category: String, expected: String) = { + val typeConstructor = getTypeMember("Typeclass") + val pTypeConstructor = getTypeMember("ParamType") + + def getMethod[T](termName: String): Option[MethodSymbol] = { val term = TermName(termName) val combineClass = c.prefix.tree.tpe.baseClasses .find { cls => cls.asType.toType.decl(term) != NoSymbol } - .getOrElse { - c.abort( - c.enclosingPosition, - s"magnolia: the method `$termName` must be defined on the derivation object to derive typeclasses for $category" - ) - } - val firstParamBlock = combineClass.asType.toType.decl(term).asTerm.asMethod.paramLists.head - if (firstParamBlock.length != 1) - c.abort(c.enclosingPosition, - s"magnolia: the method `combine` should take a single parameter of type $expected") + combineClass.map { c => + c.asType.toType.decl(term).asTerm.asMethod + } } // FIXME: Only run these methods if they're used, particularly `dispatch` - checkMethod("combine", "case classes", "CaseClass[Typeclass, _]") - checkMethod("dispatch", "sealed traits", "SealedTrait[Typeclass, _]") + getMethod("combine").getOrElse(c.abort(c.enclosingPosition, + s"magnolia: the method `dispatch` should take a single parameter of type CaseClass[Typeclass, _]") + ) + + getMethod("dispatch").getOrElse(c.abort(c.enclosingPosition, + s"magnolia: the method `combine` should take a single parameter of type SealedTrait[Typeclass, _]") + ) def findType(key: Type): Option[TermName] = recursionStack(c.enclosingPosition).frames.find(_.genericType == key).map(_.termName(c)) @@ -226,8 +229,12 @@ object Magnolia { val obj = companionRef(genericType) val className = genericType.typeSymbol.name.decodedName.toString + val paramType: Tree = getMethod("param").map { sym => + tq"${c.prefix}.ParamType[$genericType, _]" + }.getOrElse(tq"$magnoliaPkg.Param[$typeConstructor, $genericType]") + val impl = q""" - ${c.prefix}.combine($magnoliaPkg.Magnolia.caseClass[$typeConstructor, $genericType]( + ${c.prefix}.combine($magnoliaPkg.Magnolia.caseClass[$typeConstructor, $genericType, $paramType]( $className, true, false, new $scalaPkg.Array(0), _ => $obj) ) """ @@ -294,10 +301,10 @@ object Magnolia { val assignments = caseParams.zip(defaults).zipWithIndex.map { case ((CaseParam(param, typeclass, paramType, ref), defaultVal), idx) => - q"""$paramsVal($idx) = $magnoliaPkg.Magnolia.param[$typeConstructor, $genericType, - $paramType]( - ${param.name.decodedName.toString}, $ref, $defaultVal, _.${param.name} - )""" + val paramMethod: Tree = getMethod("param").map { sym => + q"${c.prefix}.param[$genericType, $paramType]" + }.getOrElse(q"$magnoliaPkg.Magnolia.param[$typeConstructor, $genericType, $paramType]") + q"""$paramsVal($idx) = $paramMethod(${param.name.decodedName.toString}, $ref, $defaultVal, _.${param.name})""" } Some( @@ -305,20 +312,20 @@ object Magnolia { genericType, q"""{ ..$preAssignments - val $paramsVal: $scalaPkg.Array[$magnoliaPkg.Param[$typeConstructor, $genericType]] = + val $paramsVal: $scalaPkg.Array[${c.prefix}.ParamType[$genericType, _]] = new $scalaPkg.Array(${assignments.length}) ..$assignments - ${c.prefix}.combine($magnoliaPkg.Magnolia.caseClass[$typeConstructor, $genericType]( + ${c.prefix}.combine($magnoliaPkg.Magnolia.caseClass[$typeConstructor, $genericType, ${c.prefix}.ParamType[$genericType, _]]( $className, false, $isValueClass, $paramsVal, - ($fnVal: $magnoliaPkg.Param[$typeConstructor, $genericType] => Any) => + ($fnVal: ${c.prefix}.ParamType[$genericType, _] => Any) => new $genericType(..${caseParams.zipWithIndex.map { - case (typeclass, idx) => - q"$fnVal($paramsVal($idx)).asInstanceOf[${typeclass.paramType}]" - }}) + case (typeclass, idx) => + q"$fnVal($paramsVal($idx)).asInstanceOf[${typeclass.paramType}]" + }}) )) }""" ) @@ -464,13 +471,13 @@ object Magnolia { * * This method is intended to be called only from code generated by the Magnolia macro, and * should not be called directly from users' code. */ - def caseClass[Tc[_], T](name: String, + def caseClass[Tc[_], T, ParamType](name: String, obj: Boolean, valClass: Boolean, - params: Array[Param[Tc, T]], - constructor: (Param[Tc, T] => Any) => T) = - new CaseClass[Tc, T](name, obj, valClass, params) { - def construct[R](param: Param[Tc, T] => R): T = constructor(param) + params: Array[ParamType], + constructor: (ParamType => Any) => T) = + new CaseClass[Tc, T, ParamType](name, obj, valClass, params) { + def construct[R](param: ParamType => R): T = constructor(param) } } |