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package bakery
import scala.language.experimental.macros
import scala.reflect.macros.blackbox.Context
trait FailureCake {
implicit def liftAnyFails[T: Manifest]: Any = ???
// This works
// implicit def liftAny[T]: Any = ???
}
object Bakery {
def failure: Any = macro failureImpl
def failureImpl(c: Context): c.Expr[Any] = {
import c.universe._
def dslTrait(dslName: String) = {
val names = dslName.split("\\.").toList.reverse
assert(names.length >= 1, "DSL trait name must be in the valid format. DSL trait name is " + dslName)
val tpeName = newTypeName(names.head)
names.tail.reverse match {
case head :: tail ⇒
Select(tail.foldLeft[Tree](Ident(newTermName(head)))((tree, name) ⇒ Select(tree, newTermName(name))), tpeName)
case Nil ⇒
Ident(tpeName)
}
}
def composeDSL(transformedBody: Tree) =
ClassDef(Modifiers(), newTypeName("eval"), List(), Template(
List(dslTrait("bakery.FailureCake")),
emptyValDef,
List(
DefDef(Modifiers(), termNames.CONSTRUCTOR, List(), List(List()), TypeTree(),
Block(List(Apply(Select(Super(This(typeNames.EMPTY), typeNames.EMPTY), termNames.CONSTRUCTOR), List())), Literal(Constant(())))),
DefDef(Modifiers(), newTermName("main"), List(), List(List()), Ident(newTypeName("Any")), transformedBody))))
def constructor = Apply(Select(New(Ident(newTypeName("eval"))), termNames.CONSTRUCTOR), List())
c.eval(c.Expr[Any](
c.untypecheck(Block(composeDSL(Literal(Constant(1))), constructor))))
c.Expr[Any](Literal(Constant(1)))
}
}
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