Merge pull request #5385 from dotty-staging/port-gestalt-optional

Port of gestalt Optional as a test

Author: liufengyun

tests/run-separate-compilation/gestalt-optional-inline/Macro_1.scala

@@ -0,0 +1,18 @@
+// Port of https://github.com/liufengyun/gestalt/blob/master/macros/src/main/scala/gestalt/macros/Optional.scala
+// using only `inline`
+
+final class Optional[+A >: Null](val value: A) extends AnyVal {
+  def get: A = value
+  def isEmpty = value == null
+
+  inline def getOrElse[B >: A](alt: => B): B =
+     if (isEmpty) alt else value
+
+  // f is by name to beta-reduce it
+  inline def map[B >: Null](f: => A => B): Optional[B] = {
+    if (isEmpty) new Optional(null)
+    else new Optional(f(value))
+  }
+
+  override def toString = if (isEmpty) "<empty>" else s"$value"
+}

tests/run-separate-compilation/gestalt-optional-inline/Test_2.scala

@@ -0,0 +1,81 @@
+// Port of https://github.com/liufengyun/gestalt/blob/master/macros/src/test/scala/gestalt/macros/OptionalTest.scala
+
+object Test {
+
+  class C
+
+  def main(args: Array[String]): Unit = {
+    getOrElseTest()
+    mapTest()
+    simpleGetOrElseTest()
+    `don't duplicate side-effects of the prefix test`()
+     hygieneTest()
+    `owner chain corruptionTest`()
+    `typed/untyped mixup test`()
+    `the final thingTest`()
+  }
+
+  def getOrElseTest(): Unit = {
+    val opt = new Optional[String]("hello")
+    assert(opt.getOrElse("world") == "hello")
+
+    val opt2 = new Optional[String](null)
+    assert(opt2.getOrElse("hello") == "hello")
+  }
+
+  def mapTest(): Unit = {
+    val opt = new Optional[String]("hello")
+    assert(opt.map(_ + " world") == new Optional("hello world"))
+
+    val opt2 = new Optional[String](null)
+    assert(opt2.map(_ + " world") == new Optional(null))
+  }
+
+  def simpleGetOrElseTest(): Unit = {
+    val c1 = new C
+    val c2 = new C
+    val c3 = new C
+    var sideEffect = 0
+
+    val x = new Optional(c1)
+    val x1 = x.getOrElse(c2)
+    assert(x1 == c1)
+    assert(sideEffect == 0)
+
+    val y = new Optional(null)
+    val y1 = y.getOrElse({ sideEffect += 1; c3 })
+    assert(y1 == c3)
+    assert(sideEffect == 1)
+  }
+
+  def `don't duplicate side-effects of the prefix test`(): Unit = {
+    val c1 = new C
+    val c2 = new C
+    var sideEffect = 0
+
+    def x = { sideEffect += 1; new Optional(c1) }
+    val x1 = x.getOrElse(c2)
+    assert(sideEffect == 1)
+  }
+
+  def hygieneTest(): Unit = {
+    val temp = 100
+    new Optional(if (temp < 100) new C else null).getOrElse(new C)
+  }
+
+  def `owner chain corruptionTest`(): Unit = {
+    def foo(x: => Optional[C]) = x
+    foo({ val y = new Optional(null); y }).getOrElse(new C)
+  }
+
+  def `typed/untyped mixup test`(): Unit = {
+    val x1 = new Optional(new C)
+    val x2 = x1.map(_.toString)
+  }
+
+  def `the final thingTest`(): Unit = {
+    def foo(f: => C): C = f
+    val x1 = new Optional(new C)
+    val x2 = x1.map(x => foo({ val y = x; y }))
+  }
+}

tests/run-separate-compilation/gestalt-optional-staging/Macro_1.scala

@@ -0,0 +1,30 @@
+// Port of https://github.com/liufengyun/gestalt/blob/master/macros/src/main/scala/gestalt/macros/Optional.scala
+// using staging macros (only quotes and splices)
+
+import scala.quoted._
+
+final class Optional[+A >: Null](val value: A) extends AnyVal {
+  def get: A = value
+  def isEmpty = value == null
+
+  inline def getOrElse[B >: A](alt: => B): B = ~Optional.getOrElseImpl('(this), '(alt))
+
+  inline def map[B >: Null](f: A => B): Optional[B] = ~Optional.mapImpl('(this), '(f))
+
+  override def toString = if (isEmpty) "<empty>" else s"$value"
+}
+
+object Optional {
+
+  // FIXME fix issue #5097 and enable private
+  /*private*/ def getOrElseImpl[T >: Null](opt: Expr[Optional[T]], alt: Expr[T]): Expr[T] = '{
+    if ((~opt).isEmpty) ~alt else (~opt).value
+  }
+
+  // FIXME fix issue #5097 and enable private
+  /*private*/ def mapImpl[A >: Null, B >: Null : Type](opt: Expr[Optional[A]], f: Expr[A => B]): Expr[Optional[B]] = '{
+    if ((~opt).isEmpty) new Optional(null)
+    else new Optional(~f('((~opt).value)))
+  }
+
+}

tests/run-separate-compilation/gestalt-optional-staging/Test_2.scala

@@ -0,0 +1,81 @@
+// Port of https://github.com/liufengyun/gestalt/blob/master/macros/src/test/scala/gestalt/macros/OptionalTest.scala
+
+object Test {
+
+  class C
+
+  def main(args: Array[String]): Unit = {
+    getOrElseTest()
+    mapTest()
+    simpleGetOrElseTest()
+    `don't duplicate side-effects of the prefix test`()
+     hygieneTest()
+    `owner chain corruptionTest`()
+    `typed/untyped mixup test`()
+    `the final thingTest`()
+  }
+
+  def getOrElseTest(): Unit = {
+    val opt = new Optional[String]("hello")
+    assert(opt.getOrElse("world") == "hello")
+
+    val opt2 = new Optional[String](null)
+    assert(opt2.getOrElse("hello") == "hello")
+  }
+
+  def mapTest(): Unit = {
+    val opt = new Optional[String]("hello")
+    assert(opt.map(_ + " world") == new Optional("hello world"))
+
+    val opt2 = new Optional[String](null)
+    assert(opt2.map(_ + " world") == new Optional(null))
+  }
+
+  def simpleGetOrElseTest(): Unit = {
+    val c1 = new C
+    val c2 = new C
+    val c3 = new C
+    var sideEffect = 0
+
+    val x = new Optional(c1)
+    val x1 = x.getOrElse(c2)
+    assert(x1 == c1)
+    assert(sideEffect == 0)
+
+    val y = new Optional(null)
+    val y1 = y.getOrElse({ sideEffect += 1; c3 })
+    assert(y1 == c3)
+    assert(sideEffect == 1)
+  }
+
+  def `don't duplicate side-effects of the prefix test`(): Unit = {
+    val c1 = new C
+    val c2 = new C
+    var sideEffect = 0
+
+    def x = { sideEffect += 1; new Optional(c1) }
+    val x1 = x.getOrElse(c2)
+    assert(sideEffect == 1)
+  }
+
+  def hygieneTest(): Unit = {
+    val temp = 100
+    new Optional(if (temp < 100) new C else null).getOrElse(new C)
+  }
+
+  def `owner chain corruptionTest`(): Unit = {
+    def foo(x: => Optional[C]) = x
+    foo({ val y = new Optional(null); y }).getOrElse(new C)
+  }
+
+  def `typed/untyped mixup test`(): Unit = {
+    val x1 = new Optional(new C)
+    val x2 = x1.map(_.toString)
+  }
+
+  def `the final thingTest`(): Unit = {
+    def foo(f: => C): C = f
+    val x1 = new Optional(new C)
+    val x2 = x1.map(x => foo({ val y = x; y }))
+  }
+}