sbt/main/settings/SettingMacro.scala

45 lines
1.5 KiB
Scala

package sbt
package std
import Def.{Initialize,Setting}
import Types.{idFun,Id}
import appmacro.{Convert, Instance, MixedBuilder, MonadInstance}
object InitializeInstance extends MonadInstance
{
type M[x] = Initialize[x]
def app[K[L[x]], Z](in: K[Initialize], f: K[Id] => Z)(implicit a: AList[K]): Initialize[Z] = Def.app[K,Z](in)(f)(a)
def map[S,T](in: Initialize[S], f: S => T): Initialize[T] = Def.map(in)(f)
def flatten[T](in: Initialize[Initialize[T]]): Initialize[T] = Def.bind(in)(idFun[Initialize[T]])
def pure[T](t: () => T): Initialize[T] = Def.pure(t)
}
object InitializeConvert extends Convert
{
def apply[T: c.WeakTypeTag](c: reflect.macros.Context)(in: c.Tree): c.Tree =
{
val u = appmacro.ContextUtil[c.type](c)
if(in.tpe <:< u.atypeOf[Initialize[Task[T]]] || in.tpe <:< u.atypeOf[Task[T]])
c.abort(in.pos, "A setting cannot depend on a task")
else if(in.tpe <:< u.atypeOf[Initialize[T]])
{
val i = c.Expr[Initialize[T]](in)
c.universe.reify( i.splice ).tree
}
else
c.abort(in.pos, "Unknown input type: " + in.tpe)
}
}
import language.experimental.macros
import scala.reflect._
import reflect.macros._
object SettingMacro
{
def settingMacroImpl[T: c.WeakTypeTag](c: Context)(t: c.Expr[T]): c.Expr[Initialize[T]] =
Instance.contImpl[T](c, InitializeInstance, InitializeConvert, MixedBuilder)(Left(t))
def settingDynMacroImpl[T: c.WeakTypeTag](c: Context)(t: c.Expr[Initialize[T]]): c.Expr[Initialize[T]] =
Instance.contImpl[T](c, InitializeInstance, InitializeConvert, MixedBuilder)(Right(t))
}