From 5d862115bd31fcd42484293c1f64652192d95d26 Mon Sep 17 00:00:00 2001 From: Jon Pretty Date: Thu, 9 Nov 2017 16:34:18 +0000 Subject: Upgrade to SBT 1.0 and include testing binaries --- core/src/main/scala/interface.scala | 196 ++++++++-------- core/src/main/scala/magnolia.scala | 448 +++++++++++++++++++++--------------- 2 files changed, 358 insertions(+), 286 deletions(-) (limited to 'core/src/main') diff --git a/core/src/main/scala/interface.scala b/core/src/main/scala/interface.scala index ecc4379..30b473a 100644 --- a/core/src/main/scala/interface.scala +++ b/core/src/main/scala/interface.scala @@ -3,23 +3,23 @@ package magnolia import language.higherKinds /** represents a subtype of a sealed trait - * - * @tparam Typeclass type constructor for the typeclass being derived - * @tparam Type generic type of this parameter */ + * + * @tparam Typeclass type constructor for the typeclass being derived + * @tparam Type generic type of this parameter */ trait Subtype[Typeclass[_], Type] { - + /** the type of subtype */ type SType <: Type /** the name of the subtype - * - * This is the fully-qualified name of the type of subclass. */ + * + * This is the fully-qualified name of the type of subclass. */ def label: String - + /** the typeclass instance associated with this subtype - * - * This is the instance of the type `Typeclass[SType]` which will have been discovered by - * implicit search, or derived by Magnolia. */ + * + * This is the instance of the type `Typeclass[SType]` which will have been discovered by + * implicit search, or derived by Magnolia. */ def typeclass: Typeclass[SType] /** partial function defined the subset of values of `Type` which have the type of this subtype */ @@ -27,107 +27,108 @@ trait Subtype[Typeclass[_], Type] { } /** represents a parameter of a case class - * - * @tparam Typeclass type constructor for the typeclass being derived - * @tparam Type generic type of this parameter */ + * + * @tparam Typeclass type constructor for the typeclass being derived + * @tparam Type generic type of this parameter */ trait Param[Typeclass[_], Type] { - + /** the type of the parameter being represented - * - * For exmaple, for a case class, - * 
-   *  case class Person(name: String, age: Int)
-   *
- * the [[Param]] instance corresponding to the `age` parameter would have a [[PType]] equal to - * the type [[scala.Int]]. However, in practice, this type will never be universally quantified. - */ + * + * For exmaple, for a case class, + * 
+    *  case class Person(name: String, age: Int)
+    *
+ * the [[Param]] instance corresponding to the `age` parameter would have a [[PType]] equal to + * the type [[scala.Int]]. However, in practice, this type will never be universally quantified. + */ type PType - + /** the name of the parameter */ def label: String /** the typeclass instance associated with this parameter - * - * This is the instance of the type `Typeclass[PType]` which will have been discovered by - * implicit search, or derived by Magnolia. - * - * Its type is existentially quantified on this [[Param]] instance, and depending on the - * nature of the particular typeclass, it may either accept or produce types which are also - * existentially quantified on this same [[Param]] instance. */ + * + * This is the instance of the type `Typeclass[PType]` which will have been discovered by + * implicit search, or derived by Magnolia. + * + * Its type is existentially quantified on this [[Param]] instance, and depending on the + * nature of the particular typeclass, it may either accept or produce types which are also + * existentially quantified on this same [[Param]] instance. */ def typeclass: Typeclass[PType] /** provides the default value for this parameter, as defined in the case class constructor */ def default: Option[PType] /** dereferences a value of the case class type, `Type`, to access the value of the parameter - * being represented - * - * When programming generically, against an unknown case class, with unknown parameter names - * and types, it is not possible to directly access the parameter values without reflection, - * which is undesirable. This method, whose implementation is provided by the Magnolia macro, - * will dereference a case class instance to access the parameter corresponding to this - * [[Param]]. - * - * Whilst the type of the resultant parameter value cannot be universally known at the use, its - * type will be existentially quantified on this [[Param]] instance, and the return type of the - * corresponding `typeclass` method will be existentially quantified on the same value. This is - * sufficient for the compiler to determine that the two values are compatible, and the value may - * be applied to the typeclass (in whatever way that particular typeclass provides). - * - * @param param the instance of the case class to be dereferenced - * @return the parameter value */ + * being represented + * + * When programming generically, against an unknown case class, with unknown parameter names + * and types, it is not possible to directly access the parameter values without reflection, + * which is undesirable. This method, whose implementation is provided by the Magnolia macro, + * will dereference a case class instance to access the parameter corresponding to this + * [[Param]]. + * + * Whilst the type of the resultant parameter value cannot be universally known at the use, its + * type will be existentially quantified on this [[Param]] instance, and the return type of the + * corresponding `typeclass` method will be existentially quantified on the same value. This is + * sufficient for the compiler to determine that the two values are compatible, and the value may + * be applied to the typeclass (in whatever way that particular typeclass provides). + * + * @param param the instance of the case class to be dereferenced + * @return the parameter value */ def dereference(param: Type): PType } /** represents a case class or case object and the context required to construct a new typeclass - * instance corresponding to it - * - * Instances of [[CaseClass]] provide access to all of the parameters of the case class, the full - * name of the case class type, and a boolean to determine whether the type is a case class or case - * object. - * - * @param typeName the name of the case class - * @param isObject true only if this represents a case object rather than a case class - * @param parametersArray an array of [[Param]] values for this case class - * @tparam Typeclass type constructor for the typeclass being derived - * @tparam Type generic type of this parameter */ -abstract class CaseClass[Typeclass[_], Type] private[magnolia]( + * instance corresponding to it + * + * Instances of [[CaseClass]] provide access to all of the parameters of the case class, the full + * name of the case class type, and a boolean to determine whether the type is a case class or case + * object. + * + * @param typeName the name of the case class + * @param isObject true only if this represents a case object rather than a case class + * @param parametersArray an array of [[Param]] values for this case class + * @tparam Typeclass type constructor for the typeclass being derived + * @tparam Type generic type of this parameter */ +abstract class CaseClass[Typeclass[_], Type] private[magnolia] ( val typeName: String, val isObject: Boolean, - parametersArray: Array[Param[Typeclass, Type]]) { + parametersArray: Array[Param[Typeclass, Type]] +) { /** constructs a new instance of the case class type - * - * This method will be implemented by the Magnolia macro to make it possible to construct - * instances of case classes generically in user code, that is, without knowing their type - * concretely. - * - * To construct a new case class instance, the method takes a lambda which defines how each - * parameter in the new case class should be constructed. See the [[Param]] class for more - * information on constructing parameter values from a [[Param]] instance. - * - * @param makeParam lambda for converting a generic [[Param]] into the value to be used for - * this parameter in the construction of a new instance of the case class - * @return a new instance of the case class */ + * + * This method will be implemented by the Magnolia macro to make it possible to construct + * instances of case classes generically in user code, that is, without knowing their type + * concretely. + * + * To construct a new case class instance, the method takes a lambda which defines how each + * parameter in the new case class should be constructed. See the [[Param]] class for more + * information on constructing parameter values from a [[Param]] instance. + * + * @param makeParam lambda for converting a generic [[Param]] into the value to be used for + * this parameter in the construction of a new instance of the case class + * @return a new instance of the case class */ def construct[Return](makeParam: Param[Typeclass, Type] => Return): Type - + /** a sequence of [[Param]] objects representing all of the parameters in the case class - * - * For efficiency, this sequence is implemented by an `Array`, but upcast to a - * [[scala.collection.Seq]] to hide the mutable collection API. */ + * + * For efficiency, this sequence is implemented by an `Array`, but upcast to a + * [[scala.collection.Seq]] to hide the mutable collection API. */ def parameters: Seq[Param[Typeclass, Type]] = parametersArray } /** represents a sealed trait and the context required to construct a new typeclass instance - * corresponding to it - * - * Instances of `SealedTrait` provide access to all of the component subtypes of the sealed trait - * which form a coproduct, and to the fully-qualified name of the sealed trait. - * - * @param typeName the name of the sealed trait - * @param subtypesArray an array of [[Subtype]] instances for each subtype in the sealed trait - * @tparam Typeclass type constructor for the typeclass being derived - * @tparam Type generic type of this parameter */ + * corresponding to it + * + * Instances of `SealedTrait` provide access to all of the component subtypes of the sealed trait + * which form a coproduct, and to the fully-qualified name of the sealed trait. + * + * @param typeName the name of the sealed trait + * @param subtypesArray an array of [[Subtype]] instances for each subtype in the sealed trait + * @tparam Typeclass type constructor for the typeclass being derived + * @tparam Type generic type of this parameter */ final class SealedTrait[Typeclass[_], Type](val typeName: String, subtypesArray: Array[Subtype[Typeclass, Type]]) { @@ -135,16 +136,21 @@ final class SealedTrait[Typeclass[_], Type](val typeName: String, def subtypes: Seq[Subtype[Typeclass, Type]] = subtypesArray /** convenience method for delegating typeclass application to the typeclass corresponding to the - * subtype of the sealed trait which matches the type of the `value` - * - * @tparam Return the return type of the lambda, which should be inferred - * @param value the instance of the generic type whose value should be used to match on a - * particular subtype of the sealed trait - * @param handle lambda for applying the value to the typeclass for the particular subtype which - * matches - * @return the result of applying the `handle` lambda to subtype of the sealed trait which - * matches the parameter `value` */ + * subtype of the sealed trait which matches the type of the `value` + * + * @tparam Return the return type of the lambda, which should be inferred + * @param value the instance of the generic type whose value should be used to match on a + * particular subtype of the sealed trait + * @param handle lambda for applying the value to the typeclass for the particular subtype which + * matches + * @return the result of applying the `handle` lambda to subtype of the sealed trait which + * matches the parameter `value` */ def dispatch[Return](value: Type)(handle: Subtype[Typeclass, Type] => Return): Return = - subtypes.map { sub => sub.cast.andThen { v => handle(sub) } }.reduce(_ orElse _)(value) + subtypes + .map { sub => + sub.cast.andThen { v => + handle(sub) + } + } + .reduce(_ orElse _)(value) } - diff --git a/core/src/main/scala/magnolia.scala b/core/src/main/scala/magnolia.scala index a2c164e..293d0f1 100644 --- a/core/src/main/scala/magnolia.scala +++ b/core/src/main/scala/magnolia.scala @@ -10,62 +10,67 @@ object Magnolia { import CompileTimeState._ /** derives a generic typeclass instance for the type `T` - * - * This is a macro definition method which should be bound to a method defined inside a Magnolia - * generic derivation object, that is, one which defines the methods `combine`, `dispatch` and - * the type constructor, `Typeclass[_]`. This will typically look like, - * 
-   *  object Derivation {
-   *    // other definitions
-   *    implicit def gen[T]: Typeclass[T] = Magnolia.gen[T]
-   *  }
-   *
- * which would support automatic derivation of typeclass instances by calling `Derivation.gen[T]` - * or with `implicitly[Typeclass[T]]`, if the implicit method is imported into the current scope. - * - * The definition expects a type constructor called `Typeclass`, taking one *-kinded type - * parameter to be defined on the same object as a means of determining how the typeclass should - * be genericized. While this may be obvious for typeclasses like `Show[T]` which take only a - * single type parameter, Magnolia can also derive typeclass instances for types such as - * `Decoder[Format, Type]` which would typically fix the `Format` parameter while varying the - * `Type` parameter. - * - * While there is no "interface" for a derivation, in the object-oriented sense, the Magnolia - * macro expects to be able to call certain methods on the object within which it is bound to a - * method. - * - * Specifically, for deriving case classes (product types), the macro will attempt to call the - * `combine` method with an instance of [[CaseClass]], like so, - * 
-   *    <derivation>.combine(<caseClass>): Typeclass[T]
-   *
- * That is to say, the macro expects there to exist a method called `combine` on the derivation - * object, which may be called with the code above, and for it to return a type which conforms to - * the type `Typeclass[T]`. The implementation of `combine` will therefore typically look like - * this, - * 
-   *    def combine[T](caseClass: CaseClass[Typeclass, T]): Typeclass[T] = ...
-   *
- * however, there is the flexibility to provide additional type parameters or additional implicit - * parameters to the definition, provided these do not affect its ability to be invoked as - * described above. - * - * Likewise, for deriving sealed traits (coproduct or sum types), the macro will attempt to call - * the `dispatch` method with an instance of [[SealedTrait]], like so, - * 
-   *    <derivation>.dispatch(<sealedTrait>): Typeclass[T]
-   *
- * so a definition such as, - * 
-   *    def dispatch[T](sealedTrait: SealedTrait[Typeclass, T]): Typeclass[T] = ...
-   *
- * will suffice, however the qualifications regarding additional type parameters and implicit - * parameters apply equally to `dispatch` as to `combine`. - * */ + * + * This is a macro definition method which should be bound to a method defined inside a Magnolia + * generic derivation object, that is, one which defines the methods `combine`, `dispatch` and + * the type constructor, `Typeclass[_]`. This will typically look like, + * 
+    *  object Derivation {
+    *    // other definitions
+    *    implicit def gen[T]: Typeclass[T] = Magnolia.gen[T]
+    *  }
+    *
+ * which would support automatic derivation of typeclass instances by calling + * `Derivation.gen[T]` or with `implicitly[Typeclass[T]]`, if the implicit method is imported + * into the current scope. + * + * The definition expects a type constructor called `Typeclass`, taking one *-kinded type + * parameter to be defined on the same object as a means of determining how the typeclass should + * be genericized. While this may be obvious for typeclasses like `Show[T]` which take only a + * single type parameter, Magnolia can also derive typeclass instances for types such as + * `Decoder[Format, Type]` which would typically fix the `Format` parameter while varying the + * `Type` parameter. + * + * While there is no "interface" for a derivation, in the object-oriented sense, the Magnolia + * macro expects to be able to call certain methods on the object within which it is bound to a + * method. + * + * Specifically, for deriving case classes (product types), the macro will attempt to call the + * `combine` method with an instance of [[CaseClass]], like so, + * 
+    *    <derivation>.combine(<caseClass>): Typeclass[T]
+    *
+ * That is to say, the macro expects there to exist a method called `combine` on the derivation + * object, which may be called with the code above, and for it to return a type which conforms + * to the type `Typeclass[T]`. The implementation of `combine` will therefore typically look + * like this, + * 
+    *    def combine[T](caseClass: CaseClass[Typeclass, T]): Typeclass[T] = ...
+    *
+ * however, there is the flexibility to provide additional type parameters or additional + * implicit parameters to the definition, provided these do not affect its ability to be invoked + * as described above. + * + * Likewise, for deriving sealed traits (coproduct or sum types), the macro will attempt to call + * the `dispatch` method with an instance of [[SealedTrait]], like so, + * 
+    *    <derivation>.dispatch(<sealedTrait>): Typeclass[T]
+    *
+ * so a definition such as, + * 
+    *    def dispatch[T](sealedTrait: SealedTrait[Typeclass, T]): Typeclass[T] = ...
+    *
+ * will suffice, however the qualifications regarding additional type parameters and implicit + * parameters apply equally to `dispatch` as to `combine`. + * */ def gen[T: c.WeakTypeTag](c: whitebox.Context): c.Tree = { import c.universe._ import scala.util.{Try, Success, Failure} + val magnoliaPkg = q"_root_.magnolia" + val magnoliaObj = q"$magnoliaPkg.Magnolia" + val arrayCls = tq"_root_.scala.Array" + val typeConstructor: c.Type = c.prefix.tree.tpe.member(TypeName("Typeclass")).asType.toType.typeConstructor @@ -74,70 +79,88 @@ object Magnolia { case class Typeclass(typ: c.Type, tree: c.Tree) - def recurse[T](path: TypePath, key: Type, value: TermName)(fn: => T): - Option[T] = { + def recurse[T](path: TypePath, key: Type, value: TermName)(fn: => T): Option[T] = { + val oldRecursionStack = recursionStack.get(c.enclosingPosition) recursionStack = recursionStack.updated( c.enclosingPosition, - recursionStack.get(c.enclosingPosition).map(_.push(path, key, value)).getOrElse( - Stack(Map(), List(Frame(path, key, value)), Nil)) + oldRecursionStack.map(_.push(path, key, value)).getOrElse { + Stack(Map(), List(Frame(path, key, value)), Nil) + } ) - try Some(fn) catch { case e: Exception => None } finally { + try Some(fn) + catch { case e: Exception => None } finally { val currentStack = recursionStack(c.enclosingPosition) - recursionStack = recursionStack.updated(c.enclosingPosition, - currentStack.pop()) + recursionStack = recursionStack.updated(c.enclosingPosition, currentStack.pop()) } } val removeDeferred: Transformer = new Transformer { override def transform(tree: Tree): Tree = tree match { - case q"_root_.magnolia.Deferred.apply[$returnType](${Literal(Constant(method: String))})" => + case q"$magnoliaPkg.Deferred.apply[$returnType](${Literal(Constant(method: String))})" => q"${TermName(method)}" case _ => super.transform(tree) } } - def typeclassTree(paramName: Option[String], genericType: Type, typeConstructor: Type, + def typeclassTree(paramName: Option[String], + genericType: Type, + typeConstructor: Type, assignedName: TermName): Tree = { - + val searchType = appliedType(typeConstructor, genericType) - - findType(genericType).map { methodName => + + val deferredRef = findType(genericType).map { methodName => val methodAsString = methodName.encodedName.toString - q"_root_.magnolia.Deferred.apply[$searchType]($methodAsString)" - }.orElse { - val (inferredImplicit, newStack) = recursionStack(c.enclosingPosition).lookup(c)(searchType) { - scala.util.Try { - val genericTypeName: String = genericType.typeSymbol.name.encodedName.toString.toLowerCase - val assignedName: TermName = TermName(c.freshName(s"${genericTypeName}Typeclass")) - recurse(ChainedImplicit(genericType.toString), genericType, assignedName) { - c.inferImplicitValue(searchType, false, false) - }.get - }.toOption.orElse(directInferImplicit(genericType, typeConstructor).map(_.tree)) - } + q"$magnoliaPkg.Deferred.apply[$searchType]($methodAsString)" + } + + val foundImplicit = deferredRef.orElse { + val (inferredImplicit, newStack) = + recursionStack(c.enclosingPosition).lookup(c)(searchType) { + val implicitSearchTry = scala.util.Try { + val genericTypeName: String = + genericType.typeSymbol.name.encodedName.toString.toLowerCase + + val assignedName: TermName = TermName(c.freshName(s"${genericTypeName}Typeclass")) + + recurse(ChainedImplicit(genericType.toString), genericType, assignedName) { + c.inferImplicitValue(searchType, false, false) + }.get + } + + implicitSearchTry.toOption.orElse( + directInferImplicit(genericType, typeConstructor).map(_.tree) + ) + } recursionStack = recursionStack.updated(c.enclosingPosition, newStack) inferredImplicit - }.getOrElse { + } + + foundImplicit.getOrElse { val currentStack: Stack = recursionStack(c.enclosingPosition) val error = ImplicitNotFound(genericType.toString, - recursionStack(c.enclosingPosition).frames.map(_.path)) + recursionStack(c.enclosingPosition).frames.map(_.path)) val updatedStack = currentStack.copy(errors = error :: currentStack.errors) recursionStack = recursionStack.updated(c.enclosingPosition, updatedStack) - val stack = recursionStack(c.enclosingPosition).frames.map(_.path).mkString(" in ", "\n in ", "\n") - c.abort(c.enclosingPosition, s"magnolia: could not find typeclass for type $genericType\n$stack") + + val stackPaths = recursionStack(c.enclosingPosition).frames.map(_.path) + val stack = stackPaths.mkString(" in ", "\n in ", "\n") + + c.abort(c.enclosingPosition, + s"magnolia: could not find typeclass for type $genericType\n$stack") } } - def directInferImplicit(genericType: c.Type, - typeConstructor: Type): Option[Typeclass] = { + def directInferImplicit(genericType: c.Type, typeConstructor: Type): Option[Typeclass] = { val genericTypeName: String = genericType.typeSymbol.name.encodedName.toString.toLowerCase val assignedName: TermName = TermName(c.freshName(s"${genericTypeName}Typeclass")) val typeSymbol = genericType.typeSymbol - val classType = if(typeSymbol.isClass) Some(typeSymbol.asClass) else None + val classType = if (typeSymbol.isClass) Some(typeSymbol.asClass) else None val isCaseClass = classType.map(_.isCaseClass).getOrElse(false) val isCaseObject = classType.map(_.isModuleClass).getOrElse(false) val isSealedTrait = classType.map(_.isSealed).getOrElse(false) @@ -146,78 +169,103 @@ object Magnolia { val resultType = appliedType(typeConstructor, genericType) // FIXME: Handle AnyVals - val result = if(isCaseObject) { + val result = if (isCaseObject) { // FIXME: look for an alternative which isn't deprecated on Scala 2.12+ val obj = genericType.typeSymbol.companionSymbol.asTerm val className = obj.fullName val impl = q""" - ${c.prefix}.combine(_root_.magnolia.Magnolia.caseClass[$typeConstructor, $genericType]( - $className, true, new _root_.scala.Array(0), _ => $obj) + ${c.prefix}.combine($magnoliaObj.caseClass[$typeConstructor, $genericType]( + $className, true, new $arrayCls(0), _ => $obj) ) """ Some(Typeclass(genericType, impl)) - } else if(isCaseClass) { + } else if (isCaseClass) { val caseClassParameters = genericType.decls.collect { case m: MethodSymbol if m.isCaseAccessor => m.asMethod } val className = genericType.typeSymbol.fullName - case class CaseParam(sym: c.universe.MethodSymbol, typeclass: c.Tree, paramType: c.Type, ref: c.TermName) - - val caseParams: List[CaseParam] = caseClassParameters.foldLeft(List[CaseParam]()) { case (acc, param) => - val paramName = param.name.encodedName.toString - val paramType = param.returnType.substituteTypes(genericType.etaExpand.typeParams, genericType.typeArgs) + case class CaseParam(sym: c.universe.MethodSymbol, + typeclass: c.Tree, + paramType: c.Type, + ref: c.TermName) + + val caseParamsReversed: List[CaseParam] = caseClassParameters.foldLeft(List[CaseParam]()) { + case (acc, param) => + val paramName = param.name.encodedName.toString + val paramType = param.returnType.substituteTypes(genericType.etaExpand.typeParams, + genericType.typeArgs) + + val predefinedRef = acc.find(_.paramType == paramType) + + val caseParamOpt = predefinedRef.map { backRef => + CaseParam(param, q"()", paramType, backRef.ref) :: acc + } + + caseParamOpt.getOrElse { + val derivedImplicit = + recurse(ProductType(paramName, genericType.toString), genericType, assignedName) { + typeclassTree(Some(paramName), paramType, typeConstructor, assignedName) + }.getOrElse( + c.abort(c.enclosingPosition, s"failed to get implicit for type $genericType") + ) + + val ref = TermName(c.freshName("paramTypeclass")) + val assigned = q"""val $ref = $derivedImplicit""" + CaseParam(param, assigned, paramType, ref) :: acc + } + } - acc.find(_.paramType == paramType).map { backRef => - CaseParam(param, q"()", paramType, backRef.ref) :: acc - }.getOrElse { - val derivedImplicit = recurse(ProductType(paramName, genericType.toString), genericType, - assignedName) { - typeclassTree(Some(paramName), paramType, typeConstructor, assignedName) - }.getOrElse(c.abort(c.enclosingPosition, s"failed to get implicit for type $genericType")) - - val ref = TermName(c.freshName("paramTypeclass")) - val assigned = q"""val $ref = $derivedImplicit""" - CaseParam(param, assigned, paramType, ref) :: acc - } - }.to[List].reverse + val caseParams = caseParamsReversed.reverse val paramsVal: TermName = TermName(c.freshName("parameters")) val fnVal: TermName = TermName(c.freshName("fn")) - + val preAssignments = caseParams.map(_.typeclass) - + val caseClassCompanion = genericType.companion - val defaults = caseClassCompanion.decl(TermName("apply")).asMethod.paramLists.head.map(_.asTerm).zipWithIndex.map { case (p, idx) => - if(p.isParamWithDefault) q"_root_.scala.Some(${genericType.typeSymbol.companionSymbol.asTerm}.${TermName("apply$default$"+(idx + 1))})" - else q"_root_.scala.None" + val constructorMethod = caseClassCompanion.decl(TermName("apply")).asMethod + val indexedConstructorParams = constructorMethod.paramLists.head.map(_.asTerm).zipWithIndex + + val defaults = indexedConstructorParams.map { + case (p, idx) => + if (p.isParamWithDefault) { + val method = TermName("apply$default$" + (idx + 1)) + q"_root_.scala.Some(${genericType.typeSymbol.companionSymbol.asTerm}.$method)" + } else q"_root_.scala.None" } - val assignments = caseParams.zip(defaults).zipWithIndex.map { case ((CaseParam(param, typeclass, paramType, ref), defaultVal), idx) => - q"""$paramsVal($idx) = _root_.magnolia.Magnolia.param[$typeConstructor, $genericType, $paramType]( + val assignments = caseParams.zip(defaults).zipWithIndex.map { + case ((CaseParam(param, typeclass, paramType, ref), defaultVal), idx) => + q"""$paramsVal($idx) = $magnoliaObj.param[$typeConstructor, $genericType, + $paramType]( ${param.name.toString}, $ref, $defaultVal, _.${TermName(param.name.toString)} )""" } - Some(Typeclass(genericType, - q"""{ + Some( + Typeclass( + genericType, + q"""{ ..$preAssignments - val $paramsVal: _root_.scala.Array[Param[$typeConstructor, $genericType]] = - new _root_.scala.Array(${assignments.length}) + val $paramsVal: $arrayCls[Param[$typeConstructor, $genericType]] = + new $arrayCls(${assignments.length}) ..$assignments - ${c.prefix}.combine(_root_.magnolia.Magnolia.caseClass[$typeConstructor, $genericType]( + ${c.prefix}.combine($magnoliaObj.caseClass[$typeConstructor, $genericType]( $className, false, $paramsVal, ($fnVal: Param[$typeConstructor, $genericType] => Any) => - new $genericType(..${caseParams.zipWithIndex.map { case (typeclass, idx) => - q"$fnVal($paramsVal($idx)).asInstanceOf[${typeclass.paramType}]" + new $genericType(..${caseParams.zipWithIndex.map { + case (typeclass, idx) => + q"$fnVal($paramsVal($idx)).asInstanceOf[${typeclass.paramType}]" } }) )) }""" - )) - } else if(isSealedTrait) { + ) + ) + } else if (isSealedTrait) { val genericSubtypes = classType.get.knownDirectSubclasses.to[List] val subtypes = genericSubtypes.map { sub => val typeArgs = sub.asType.typeSignature.baseType(genericType.typeSymbol).typeArgs @@ -226,47 +274,55 @@ object Magnolia { appliedType(sub.asType.toType.typeConstructor, newTypeParams) } - if(subtypes.isEmpty) { + if (subtypes.isEmpty) { c.info(c.enclosingPosition, - s"magnolia: could not find any direct subtypes of $typeSymbol", true) - + s"magnolia: could not find any direct subtypes of $typeSymbol", + true) + c.abort(c.enclosingPosition, "") } - + val subtypesVal: TermName = TermName(c.freshName("subtypes")) - - val assignments = subtypes.map { searchType => + + val typeclasses = subtypes.map { searchType => recurse(CoproductType(genericType.toString), genericType, assignedName) { (searchType, typeclassTree(None, searchType, typeConstructor, assignedName)) }.getOrElse { c.abort(c.enclosingPosition, s"failed to get implicit for type $searchType") } - }.zipWithIndex.map { case ((typ, typeclass), idx) => - q"""$subtypesVal($idx) = _root_.magnolia.Magnolia.subtype[$typeConstructor, $genericType, $typ]( + } + + val assignments = typeclasses.zipWithIndex.map { + case ((typ, typeclass), idx) => + q"""$subtypesVal($idx) = $magnoliaObj.subtype[$typeConstructor, $genericType, $typ]( ${typ.typeSymbol.fullName}, $typeclass, (t: $genericType) => t.isInstanceOf[$typ], (t: $genericType) => t.asInstanceOf[$typ] )""" } - + Some { - Typeclass(genericType, q"""{ - val $subtypesVal: _root_.scala.Array[_root_.magnolia.Subtype[$typeConstructor, $genericType]] = - new _root_.scala.Array(${assignments.size}) + Typeclass( + genericType, + q"""{ + val $subtypesVal: $arrayCls[_root_.magnolia.Subtype[$typeConstructor, $genericType]] = + new $arrayCls(${assignments.size}) ..$assignments ${c.prefix}.dispatch(new _root_.magnolia.SealedTrait( $genericTypeName, - $subtypesVal: _root_.scala.Array[_root_.magnolia.Subtype[$typeConstructor, $genericType]]) + $subtypesVal: $arrayCls[_root_.magnolia.Subtype[$typeConstructor, $genericType]]) ): $resultType - }""") + }""" + ) } } else None - result.map { case Typeclass(t, r) => - Typeclass(t, q"""{ + result.map { + case Typeclass(t, r) => + Typeclass(t, q"""{ def $assignedName: $resultType = $r $assignedName }""") @@ -274,27 +330,27 @@ object Magnolia { } val genericType: Type = weakTypeOf[T] - + val currentStack: Stack = recursionStack.get(c.enclosingPosition).getOrElse(Stack(Map(), List(), List())) - + val directlyReentrant = Some(genericType) == currentStack.frames.headOption.map(_.genericType) - - if(directlyReentrant) throw DirectlyReentrantException() - + + if (directlyReentrant) throw DirectlyReentrantException() + currentStack.errors.foreach { error => - if(!emittedErrors.contains(error)) { + if (!emittedErrors.contains(error)) { emittedErrors += error val trace = error.path.mkString("\n in ", "\n in ", "\n \n") - - val msg = s"magnolia: could not derive ${typeConstructor} instance for type "+ - s"${error.genericType}" - - c.info(c.enclosingPosition, msg+trace, true) + + val msg = s"magnolia: could not derive ${typeConstructor} instance for type " + + s"${error.genericType}" + + c.info(c.enclosingPosition, msg + trace, true) } } - val result: Option[Tree] = if(!currentStack.frames.isEmpty) { + val result: Option[Tree] = if (!currentStack.frames.isEmpty) { findType(genericType) match { case None => directInferImplicit(genericType, typeConstructor).map(_.tree) @@ -304,90 +360,100 @@ object Magnolia { Some(q"_root_.magnolia.Deferred[$searchType]($methodAsString)") } } else directInferImplicit(genericType, typeConstructor).map(_.tree) - - if(currentStack.frames.isEmpty) recursionStack = ListMap() - result.map { tree => - if(currentStack.frames.isEmpty) c.untypecheck(removeDeferred.transform(tree)) else tree - }.getOrElse { + if (currentStack.frames.isEmpty) recursionStack = ListMap() + + val dereferencedResult = result.map { tree => + if (currentStack.frames.isEmpty) c.untypecheck(removeDeferred.transform(tree)) else tree + } + + dereferencedResult.getOrElse { c.abort(c.enclosingPosition, s"magnolia: could not infer typeclass for type $genericType") } } /** constructs a new [[Subtype]] instance - * - * 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 subtype[Tc[_], T, S <: T](name: String, tc: => Tc[S], isType: T => Boolean, asType: T => S) = new Subtype[Tc, T] { - type SType = S - def label: String = name - def typeclass: Tc[SType] = tc - def cast: PartialFunction[T, SType] = new PartialFunction[T, S] { - def isDefinedAt(t: T) = isType(t) - def apply(t: T): SType = asType(t) + * + * 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 subtype[Tc[_], T, S <: T](name: String, tc: => Tc[S], isType: T => Boolean, asType: T => S) = + new Subtype[Tc, T] { + type SType = S + def label: String = name + def typeclass: Tc[SType] = tc + def cast: PartialFunction[T, SType] = new PartialFunction[T, S] { + def isDefinedAt(t: T) = isType(t) + def apply(t: T): SType = asType(t) + } } - } /** constructs a new [[Param]] instance - * - * 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 param[Tc[_], T, P](name: String, typeclassParam: Tc[P], defaultVal: => Option[P], deref: T => P) = new Param[Tc, T] { + * + * 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 param[Tc[_], T, P](name: String, + typeclassParam: Tc[P], + defaultVal: => Option[P], + deref: T => P) = new Param[Tc, T] { type PType = P def label: String = name def default: Option[PType] = defaultVal def typeclass: Tc[PType] = typeclassParam def dereference(t: T): PType = deref(t) } - + /** constructs a new [[CaseClass]] instance - * - * 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, obj: Boolean, params: Array[Param[Tc, T]], constructor: (Param[Tc, T] => Any) => T) = + * + * 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, + obj: Boolean, + params: Array[Param[Tc, T]], + constructor: (Param[Tc, T] => Any) => T) = new CaseClass[Tc, T](name, obj, params) { def construct[R](param: Param[Tc, T] => R): T = constructor(param) } } -private[magnolia] case class DirectlyReentrantException() extends - Exception("attempt to recurse directly") +private[magnolia] case class DirectlyReentrantException() + extends Exception("attempt to recurse directly") private[magnolia] object Deferred { def apply[T](method: String): T = ??? } private[magnolia] object CompileTimeState { sealed class TypePath(path: String) { override def toString = path } - case class CoproductType(typeName: String) extends - TypePath(s"coproduct type $typeName") - - case class ProductType(paramName: String, typeName: String) extends - TypePath(s"parameter '$paramName' of product type $typeName") - - case class ChainedImplicit(typeName: String) extends - TypePath(s"chained implicit of type $typeName") + case class CoproductType(typeName: String) extends TypePath(s"coproduct type $typeName") + + case class ProductType(paramName: String, typeName: String) + extends TypePath(s"parameter '$paramName' of product type $typeName") + + case class ChainedImplicit(typeName: String) + extends TypePath(s"chained implicit of type $typeName") case class ImplicitNotFound(genericType: String, path: List[TypePath]) - case class Stack(cache: Map[whitebox.Context#Type, Option[whitebox.Context#Tree]], frames: List[Frame], errors: List[ImplicitNotFound]) { - + case class Stack(cache: Map[whitebox.Context#Type, Option[whitebox.Context#Tree]], + frames: List[Frame], + errors: List[ImplicitNotFound]) { + def lookup(c: whitebox.Context)(t: c.Type)(orElse: => Option[c.Tree]): (Option[c.Tree], Stack) = - if(cache.contains(t)) { + if (cache.contains(t)) { (cache(t).asInstanceOf[Option[c.Tree]], this) } else { val value = orElse (value, copy(cache.updated(t, value))) } - def push(path: TypePath, key: whitebox.Context#Type, - value: whitebox.Context#TermName): Stack = + def push(path: TypePath, key: whitebox.Context#Type, value: whitebox.Context#TermName): Stack = Stack(cache, Frame(path, key, value) :: frames, errors) - + def pop(): Stack = Stack(cache, frames.tail, errors) } - case class Frame(path: TypePath, genericType: whitebox.Context#Type, - term: whitebox.Context#TermName) { + case class Frame(path: TypePath, + genericType: whitebox.Context#Type, + term: whitebox.Context#TermName) { def termName(c: whitebox.Context): c.TermName = term.asInstanceOf[c.TermName] } -- cgit v1.2.3