/
Yield.scala
198 lines (162 loc) · 8.01 KB
/
Yield.scala
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package com.thoughtworks.dsl.keywords
import com.thoughtworks.dsl.Dsl
import com.thoughtworks.dsl.Dsl.Keyword
import com.thoughtworks.dsl.keywords.Yield.From
import com.thoughtworks.enableMembersIf
import scala.collection._
import scala.collection.generic.CanBuildFrom
import scala.concurrent.Future
import scala.language.implicitConversions
import scala.language.higherKinds
/**
* @author 杨博 (Yang Bo)
* @example This `Yield` keyword must be put inside a function that returns `Seq[Element]` or `Seq[Element] !! ...`,
* or it will not compile.
*
* {{{
* "def f(): Int = !Yield(1)" shouldNot compile
* }}}
*
*/
final case class Yield[Element](element: Element) extends AnyVal with Keyword[Yield[Element], Unit]
private[keywords] trait LowPriorityYield2 {
def apply[A](elements: A*) = {
From(elements)
}
implicit def iteratorYieldFromDsl[A, FromCollection <: TraversableOnce[A]]
: Dsl[From[FromCollection], Iterator[A], Unit] =
new Dsl[From[FromCollection], Iterator[A], Unit] {
def cpsApply(keyword: From[FromCollection], generateTail: Unit => Iterator[A]): Iterator[A] = {
keyword.elements.toIterator ++ generateTail(())
}
}
implicit def iteratorYieldDsl[A, B >: A]: Dsl[Yield[A], Iterator[B], Unit] =
new Dsl[Yield[A], Iterator[B], Unit] {
def cpsApply(keyword: Yield[A], generateTail: Unit => Iterator[B]): Iterator[B] = {
Iterator.single(keyword.element) ++ generateTail(())
}
}
}
private[keywords] object YieldScalaVersions {
@enableMembersIf(scala.util.Properties.versionNumberString.matches("""^2\.1(1|2)\..*$"""))
object Scala211Or212 {
trait LowPriorityYield1 extends LowPriorityYield2 {
implicit def seqViewYieldFromDsl[A, FromCollection <: Traversable[A], Coll1, Coll2](
implicit canBuildFrom: CanBuildFrom[SeqView[A, Coll1], A, SeqView[A, Coll2]])
: Dsl[From[FromCollection], SeqView[A, Coll1], Unit] =
new Dsl[From[FromCollection], SeqView[A, Coll1], Unit] {
def cpsApply(keyword: From[FromCollection], generateTail: Unit => SeqView[A, Coll1]): SeqView[A, Coll1] = {
(keyword.elements.toIterable ++: generateTail(()))(canBuildFrom).asInstanceOf[SeqView[A, Coll1]]
}
}
implicit def seqViewYieldDsl[A, B >: A, Coll1, Coll2](
implicit canBuildFrom: CanBuildFrom[scala.collection.SeqView[B, Coll1], B, SeqView[B, Coll2]])
: Dsl[Yield[A], SeqView[B, Coll1], Unit] =
new Dsl[Yield[A], SeqView[B, Coll1], Unit] {
def cpsApply(keyword: Yield[A], generateTail: Unit => SeqView[B, Coll1]): SeqView[B, Coll1] = {
(keyword.element +: generateTail(()))(canBuildFrom).asInstanceOf[SeqView[B, Coll1]]
}
}
}
trait LowPriorityYield0 extends LowPriorityYield1 {
implicit def seqYieldFromDsl[A, FromCollection <: Iterable[A], Collection[X] <: SeqLike[X, Collection[X]]](
implicit canBuildFrom: CanBuildFrom[Collection[A], A, Collection[A]])
: Dsl[From[FromCollection], Collection[A], Unit] =
new Dsl[From[FromCollection], Collection[A], Unit] {
def cpsApply(keyword: From[FromCollection], generateTail: Unit => Collection[A]): Collection[A] = {
keyword.elements ++: generateTail(())
}
}
implicit def seqYieldDsl[A, B >: A, Collection[X] <: SeqLike[X, Collection[X]]](
implicit canBuildFrom: CanBuildFrom[Collection[B], B, Collection[B]]): Dsl[Yield[A], Collection[B], Unit] =
new Dsl[Yield[A], Collection[B], Unit] {
def cpsApply(keyword: Yield[A], generateTail: Unit => Collection[B]): Collection[B] = {
keyword.element +: generateTail(())
}
}
}
}
@enableMembersIf(scala.util.Properties.versionNumberString.matches("""^2\.13\..*$"""))
object Scala213 {
trait LowPriorityYield1 extends LowPriorityYield2 {
implicit def viewYieldFromDsl[A, FromCollection <: View.SomeIterableOps[A]]
: Dsl[From[FromCollection], View[A], Unit] =
new Dsl[From[FromCollection], View[A], Unit] {
def cpsApply(keyword: From[FromCollection], generateTail: Unit => View[A]): View[A] = {
new View.Concat(keyword.elements, generateTail(()))
}
}
implicit def seqViewYieldDsl[A, B >: A]: Dsl[Yield[A], SeqView[B], Unit] =
new Dsl[Yield[A], SeqView[B], Unit] {
def cpsApply(keyword: Yield[A], generateTail: Unit => SeqView[B]): SeqView[B] = {
generateTail(()).prepended(keyword.element)
}
}
implicit def indexedSeqViewYieldDsl[A, B >: A]: Dsl[Yield[A], IndexedSeqView[B], Unit] =
new Dsl[Yield[A], IndexedSeqView[B], Unit] {
def cpsApply(keyword: Yield[A], generateTail: Unit => IndexedSeqView[B]): IndexedSeqView[B] = {
generateTail(()).prepended(keyword.element)
}
}
implicit def viewYieldDsl[A, B >: A]: Dsl[Yield[A], View[B], Unit] =
new Dsl[Yield[A], View[B], Unit] {
def cpsApply(keyword: Yield[A], generateTail: Unit => View[B]): View[B] = {
new View.Concat[B](new View.Single(keyword.element), generateTail(()))
}
}
}
trait LowPriorityYield0 extends LowPriorityYield1 {
implicit def seqYieldFromDsl[A,
FromCollection <: View.SomeIterableOps[A],
Collection[X] <: SeqOps[X, Collection, Collection[X]]]
: Dsl[From[FromCollection], Collection[A], Unit] =
new Dsl[From[FromCollection], Collection[A], Unit] {
def cpsApply(keyword: From[FromCollection], generateTail: Unit => Collection[A]): Collection[A] = {
keyword.elements.toIterable ++: generateTail(())
}
}
implicit def seqYieldDsl[A, B >: A, Collection[+X] <: SeqOps[X, Collection, Collection[X]]]
: Dsl[Yield[A], Collection[B], Unit] =
new Dsl[Yield[A], Collection[B], Unit] {
def cpsApply(keyword: Yield[A], generateTail: Unit => Collection[B]): Collection[B] = {
keyword.element +: generateTail(())
}
}
}
}
}
import YieldScalaVersions.Scala211Or212._
import YieldScalaVersions.Scala213._
object Yield extends LowPriorityYield0 {
final case class From[FromCollection <: TraversableOnce[_]](elements: FromCollection)
extends AnyVal
with Keyword[From[FromCollection], Unit]
implicit def implicitYieldFrom[FromCollection <: TraversableOnce[_]](elements: FromCollection): From[FromCollection] =
From(elements)
implicit def streamYieldFromDsl[A, FromCollection <: Iterable[A]]: Dsl[From[FromCollection], Stream[A], Unit] =
new Dsl[From[FromCollection], Stream[A], Unit] {
def cpsApply(keyword: From[FromCollection], generateTail: Unit => Stream[A]): Stream[A] = {
keyword.elements.toStream.append(generateTail(()))
}
}
implicit def futureStreamYieldFromDsl[A, FromCollection <: Iterable[A]]
: Dsl[From[FromCollection], Stream[Future[A]], Unit] =
new Dsl[From[FromCollection], Stream[Future[A]], Unit] {
def cpsApply(keyword: From[FromCollection], generateTail: Unit => Stream[Future[A]]): Stream[Future[A]] = {
keyword.elements.toStream.map(Future.successful).append(generateTail(()))
}
}
implicit def implicitYield[Element](element: Element): Yield[Element] = Yield[Element](element)
implicit def streamYieldDsl[Element, That >: Element]: Dsl[Yield[Element], Stream[That], Unit] =
new Dsl[Yield[Element], Stream[That], Unit] {
def cpsApply(keyword: Yield[Element], generateTail: Unit => Stream[That]): Stream[That] = {
new Stream.Cons(keyword.element, generateTail(()))
}
}
implicit def futureStreamYieldDsl[Element, That >: Element]: Dsl[Yield[Element], Stream[Future[That]], Unit] =
new Dsl[Yield[Element], Stream[Future[That]], Unit] {
def cpsApply(keyword: Yield[Element], generateTail: Unit => Stream[Future[That]]): Stream[Future[That]] = {
new Stream.Cons(Future.successful(keyword.element), generateTail(()))
}
}
}