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author | Loic Descotte <loic.descotte@gmail.com> | 2017-11-11 08:04:42 +0100 |
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committer | Loic Descotte <loic.descotte@gmail.com> | 2017-11-11 08:24:30 +0100 |
commit | 2cd897dd1bb05981fac1fc9d61ee32f26a16c35b (patch) | |
tree | c2fb5fa0a884f501e053eb979e6dd0862f54336e /core/src | |
parent | efe98a7d0b134415f3da0e7a7c3cb6ca5f2b44c4 (diff) | |
download | magnolia-2cd897dd1bb05981fac1fc9d61ee32f26a16c35b.tar.gz magnolia-2cd897dd1bb05981fac1fc9d61ee32f26a16c35b.tar.bz2 magnolia-2cd897dd1bb05981fac1fc9d61ee32f26a16c35b.zip |
scalajs cross build
Diffstat (limited to 'core/src')
-rw-r--r-- | core/src/main/scala/interface.scala | 157 | ||||
-rw-r--r-- | core/src/main/scala/magnolia.scala | 522 |
2 files changed, 0 insertions, 679 deletions
diff --git a/core/src/main/scala/interface.scala b/core/src/main/scala/interface.scala deleted file mode 100644 index 54f8ce3..0000000 --- a/core/src/main/scala/interface.scala +++ /dev/null @@ -1,157 +0,0 @@ -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 */ -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. */ - 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. */ - def typeclass: Typeclass[SType] - - /** partial function defined the subset of values of `Type` which have the type of this subtype */ - def cast: PartialFunction[Type, SType] -} - -/** represents a parameter of a case class - * - * @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, - * <pre> - * case class Person(name: String, age: Int) - * </pre> - * 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. */ - 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 */ - 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] ( - val typeName: String, - val isObject: Boolean, - val isValueClass: Boolean, - 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 */ - 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. */ - 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 */ -final class SealedTrait[Typeclass[_], Type](val typeName: String, - subtypesArray: Array[Subtype[Typeclass, Type]]) { - - /** a sequence of all the subtypes of this sealed trait */ - 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` */ - def dispatch[Return](value: Type)(handle: Subtype[Typeclass, Type] => Return): Return = - 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 deleted file mode 100644 index 51f594d..0000000 --- a/core/src/main/scala/magnolia.scala +++ /dev/null @@ -1,522 +0,0 @@ -package magnolia - -import scala.reflect._, macros._ -import scala.collection.immutable.ListMap -import language.existentials -import language.higherKinds - -/** the object which defines the Magnolia macro */ -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, - * <pre> - * object Derivation { - * // other definitions - * implicit def gen[T]: Typeclass[T] = Magnolia.gen[T] - * } - * </pre> - * 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, - * <pre> - * <derivation>.combine(<caseClass>): Typeclass[T] - * </pre> - * 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, - * <pre> - * def combine[T](caseClass: CaseClass[Typeclass, T]): Typeclass[T] = ... - * </pre> - * 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, - * <pre> - * <derivation>.dispatch(<sealedTrait>): Typeclass[T] - * </pre> - * so a definition such as, - * <pre> - * def dispatch[T](sealedTrait: SealedTrait[Typeclass, T]): Typeclass[T] = ... - * </pre> - * 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"$magnoliaPkg.Magnolia" - val arrayCls = tq"_root_.scala.Array" - - val prefixType = c.prefix.tree.tpe - - def companionRef(tpe: Type): Tree = { - val global = c.universe match { case global: scala.tools.nsc.Global => global } - val globalTpe = tpe.asInstanceOf[global.Type] - val companion = globalTpe.typeSymbol.companionSymbol - if (companion != NoSymbol) - global.gen.mkAttributedRef(globalTpe.prefix, companion).asInstanceOf[Tree] - else q"${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) - } - } - - 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") - } - - def checkMethod(termName: String, category: String, expected: String) = { - 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 $expected") - } - - // FIXME: Only run these methods if they're used, particularly `dispatch` - checkMethod("combine", "case classes", "CaseClass[Typeclass, _]") - checkMethod("dispatch", "sealed traits", "SealedTrait[Typeclass, _]") - - def findType(key: Type): Option[TermName] = - recursionStack(c.enclosingPosition).frames.find(_.genericType == key).map(_.termName(c)) - - case class Typeclass(typ: c.Type, tree: c.Tree) - - def recurse[T](path: TypePath, key: Type, value: TermName)(fn: => T): Option[T] = { - val oldRecursionStack = recursionStack.get(c.enclosingPosition) - recursionStack = recursionStack.updated( - c.enclosingPosition, - oldRecursionStack.map(_.push(path, key, value)).getOrElse { - Stack(Map(), List(Frame(path, key, value)), Nil) - } - ) - - try Some(fn) - catch { case e: Exception => None } finally { - val currentStack = recursionStack(c.enclosingPosition) - recursionStack = recursionStack.updated(c.enclosingPosition, currentStack.pop()) - } - } - - val removeDeferred: Transformer = new Transformer { - override def transform(tree: Tree): Tree = tree match { - case q"$magnoliaPkg.Deferred.apply[$returnType](${Literal(Constant(method: String))})" => - q"${TermName(method)}" - case _ => - super.transform(tree) - } - } - - def typeclassTree(paramName: Option[String], - genericType: Type, - typeConstructor: Type, - assignedName: TermName): Tree = { - - val searchType = appliedType(typeConstructor, genericType) - - val deferredRef = findType(genericType).map { methodName => - val methodAsString = methodName.decodedName.toString - q"$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.decodedName.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 - } - - foundImplicit.getOrElse { - val currentStack: Stack = recursionStack(c.enclosingPosition) - - val error = ImplicitNotFound(genericType.toString, - recursionStack(c.enclosingPosition).frames.map(_.path)) - - val updatedStack = currentStack.copy(errors = error :: currentStack.errors) - recursionStack = recursionStack.updated(c.enclosingPosition, updatedStack) - - 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] = { - - val genericTypeName: String = genericType.typeSymbol.name.decodedName.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 isCaseClass = classType.map(_.isCaseClass).getOrElse(false) - val isCaseObject = classType.map(_.isModuleClass).getOrElse(false) - val isSealedTrait = classType.map(_.isSealed).getOrElse(false) - - val primitives = Set(typeOf[Double], - typeOf[Float], - typeOf[Short], - typeOf[Byte], - typeOf[Int], - typeOf[Long], - typeOf[Char], - typeOf[Boolean]) - - val isValueClass = genericType <:< typeOf[AnyVal] && !primitives.exists(_ =:= genericType) - - val resultType = appliedType(typeConstructor, genericType) - - val result = if (isCaseObject) { - // FIXME: look for an alternative which isn't deprecated on Scala 2.12+ - val obj = companionRef(genericType) - val className = genericType.typeSymbol.name.decodedName.toString - - val impl = q""" - ${c.prefix}.combine($magnoliaObj.caseClass[$typeConstructor, $genericType]( - $className, true, false, new $arrayCls(0), _ => $obj) - ) - """ - Some(Typeclass(genericType, impl)) - } else if (isCaseClass || isValueClass) { - val caseClassParameters = genericType.decls.collect { - case m: MethodSymbol if m.isCaseAccessor || (isValueClass && m.isParamAccessor) => - m.asMethod - } - val className = genericType.typeSymbol.name.decodedName.toString - - 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.decodedName.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 = $derivedImplicit""" - CaseParam(param, assigned, paramType, ref) :: acc - } - } - - val caseParams = caseParamsReversed.reverse - - val paramsVal: TermName = TermName(c.freshName("parameters")) - val fnVal: TermName = TermName(c.freshName("fn")) - - val preAssignments = caseParams.map(_.typeclass) - - val defaults = if (!isValueClass) { - val caseClassCompanion = genericType.companion - val constructorMethod = caseClassCompanion.decl(TermName("apply")).asMethod - val indexedConstructorParams = - constructorMethod.paramLists.head.map(_.asTerm).zipWithIndex - - indexedConstructorParams.map { - case (p, idx) => - if (p.isParamWithDefault) { - val method = TermName("apply$default$" + (idx + 1)) - q"_root_.scala.Some(${genericType.typeSymbol.companion.asTerm}.$method)" - } else q"_root_.scala.None" - } - } else List(q"_root_.scala.None") - - val assignments = caseParams.zip(defaults).zipWithIndex.map { - case ((CaseParam(param, typeclass, paramType, ref), defaultVal), idx) => - q"""$paramsVal($idx) = $magnoliaObj.param[$typeConstructor, $genericType, - $paramType]( - ${param.name.decodedName.toString}, $ref, $defaultVal, _.${param.name} - )""" - } - - Some( - Typeclass( - genericType, - q"""{ - ..$preAssignments - val $paramsVal: $arrayCls[Param[$typeConstructor, $genericType]] = - new $arrayCls(${assignments.length}) - ..$assignments - - ${c.prefix}.combine($magnoliaObj.caseClass[$typeConstructor, $genericType]( - $className, - false, - $isValueClass, - $paramsVal, - ($fnVal: Param[$typeConstructor, $genericType] => Any) => - new $genericType(..${caseParams.zipWithIndex.map { - case (typeclass, idx) => - q"$fnVal($paramsVal($idx)).asInstanceOf[${typeclass.paramType}]" - }}) - )) - }""" - ) - ) - } else if (isSealedTrait) { - val genericSubtypes = classType.get.knownDirectSubclasses.to[List] - val subtypes = genericSubtypes.map { sub => - val typeArgs = sub.asType.typeSignature.baseType(genericType.typeSymbol).typeArgs - val mapping = typeArgs.zip(genericType.typeArgs).toMap - val newTypeParams = sub.asType.toType.typeArgs.map(mapping(_)) - appliedType(sub.asType.toType.typeConstructor, newTypeParams) - } - - if (subtypes.isEmpty) { - c.info(c.enclosingPosition, - s"magnolia: could not find any direct subtypes of $typeSymbol", - true) - - c.abort(c.enclosingPosition, "") - } - - val subtypesVal: TermName = TermName(c.freshName("subtypes")) - - 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 $searchType") - } - } - - val assignments = typeclasses.zipWithIndex.map { - case ((typ, typeclass), idx) => - q"""$subtypesVal($idx) = $magnoliaObj.subtype[$typeConstructor, $genericType, $typ]( - ${typ.typeSymbol.fullName.toString}, - $typeclass, - (t: $genericType) => t.isInstanceOf[$typ], - (t: $genericType) => t.asInstanceOf[$typ] - )""" - } - - Some { - 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: $arrayCls[_root_.magnolia.Subtype[$typeConstructor, $genericType]]) - ): $resultType - }""" - ) - } - } else None - - result.map { - case Typeclass(t, r) => - Typeclass(t, q"""{ - def $assignedName: $resultType = $r - $assignedName - }""") - } - } - - 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() - - currentStack.errors.foreach { 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 result: Option[Tree] = if (!currentStack.frames.isEmpty) { - findType(genericType) match { - case None => - directInferImplicit(genericType, typeConstructor).map(_.tree) - case Some(enclosingRef) => - val methodAsString = enclosingRef.toString - val searchType = appliedType(typeConstructor, genericType) - Some(q"_root_.magnolia.Deferred[$searchType]($methodAsString)") - } - } else directInferImplicit(genericType, typeConstructor).map(_.tree) - - 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) - } - } - - /** 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] { - 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, - 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) - } -} - -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 ImplicitNotFound(genericType: String, path: List[TypePath]) - - 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)) { - (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 = - 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) { - def termName(c: whitebox.Context): c.TermName = term.asInstanceOf[c.TermName] - } - - var recursionStack: ListMap[api.Position, Stack] = ListMap() - var emittedErrors: Set[ImplicitNotFound] = Set() -} |