Unit annotations

src/compiler/scala/reflect/quasiquotes/Placeholders.scala

@@ -32,7 +32,7 @@ trait Placeholders { self: Quasiquotes =>
   lazy val code = {
     val sb = new StringBuilder()
 
-    def appendPart(value: String, pos: Position) = {
+    def appendPart(value: String, pos: Position): Unit = {
       val start = sb.length
       sb.append(value)
       val end = sb.length

src/compiler/scala/reflect/reify/Reifier.scala

@@ -65,12 +65,14 @@ abstract class Reifier extends States
       if (universe exists (_.isErroneous)) CannotReifyErroneousPrefix(universe)
       if (universe.tpe == null) CannotReifyUntypedPrefix(universe)
 
+      def reifyTraceOut[A](msg: => String)(a: A) = reifyTrace(msg)(a): Unit
+
       val result = reifee match {
         case tree: Tree =>
-          reifyTrace("reifying = ")(if (settings.Xshowtrees || settings.XshowtreesCompact || settings.XshowtreesStringified) "\n" + nodePrinters.nodeToString(tree).trim else tree.toString)
-          reifyTrace("reifee is located at: ")(tree.pos)
-          reifyTrace("universe = ")(universe)
-          reifyTrace("mirror = ")(mirror)
+          reifyTraceOut("reifying = ")(if (settings.Xshowtrees || settings.XshowtreesCompact || settings.XshowtreesStringified) "\n" + nodePrinters.nodeToString(tree).trim else tree.toString)
+          reifyTraceOut("reifee is located at: ")(tree.pos)
+          reifyTraceOut("universe = ")(universe)
+          reifyTraceOut("mirror = ")(mirror)
           if (tree exists (_.isErroneous)) CannotReifyErroneousReifee(tree)
           if (tree.tpe == null) CannotReifyUntypedReifee(tree)
           val pipeline = mkReificationPipeline
@@ -83,9 +85,9 @@ abstract class Reifier extends States
           ReifiedTree(universe, mirror, symtab, rtree, tpe, rtpe, reificationIsConcrete)
 
         case tpe: Type =>
-          reifyTrace("reifying = ")(tpe.toString)
-          reifyTrace("universe = ")(universe)
-          reifyTrace("mirror = ")(mirror)
+          reifyTraceOut("reifying = ")(tpe.toString)
+          reifyTraceOut("universe = ")(universe)
+          reifyTraceOut("mirror = ")(mirror)
           val rtree = reify(tpe)
           ReifiedType(universe, mirror, symtab, tpe, rtree, reificationIsConcrete)
 

src/compiler/scala/tools/nsc/typechecker/Infer.scala

@@ -84,12 +84,12 @@ trait Infer extends Checkable {
       val ptVars = appliedType(samTyCon, tvars)
 
       // carry over info from pt
-      ptVars <:< samTp
+      ptVars <:< samTp: Unit
 
       val samInfoWithTVars = ptVars.memberInfo(sam)
 
       // use function type subtyping, not method type subtyping (the latter is invariant in argument types)
-      funTp <:< functionType(samInfoWithTVars.paramTypes, samInfoWithTVars.finalResultType)
+      funTp <:< functionType(samInfoWithTVars.paramTypes, samInfoWithTVars.finalResultType): Unit
 
       // solve constraints tracked by tvars
       val targs = solvedTypes(tvars, tparams, varianceInType(sam.info), upper = false, lubDepth(sam.info :: Nil))
@@ -1401,7 +1401,7 @@ trait Infer extends Checkable {
           }
           // todo: missing test case for bests.isEmpty
           bests match {
-            case best :: Nil                              => tree setSymbol best setType (pre memberType best)
+            case best :: Nil                              => tree.setSymbol(best).setType(pre.memberType(best))
             case best :: competing :: _ if alts0.nonEmpty =>
               // scala/bug#6912 Don't give up and leave an OverloadedType on the tree.
               //         Originally I wrote this as `if (secondTry) ... `, but `tryTwice` won't attempt the second try

src/library/scala/MatchError.scala

@@ -23,16 +23,16 @@ final class MatchError(@transient obj: Any) extends RuntimeException {
   private[this] lazy val objString = {
     def ofClass = "of class " + obj.getClass.getName
     if (obj == null) "null"
-    else try {
-      obj.toString() + " (" + ofClass + ")"
-    } catch {
-      case _: Throwable => "an instance " + ofClass
-    }
+    else
+      try s"$obj ($ofClass)"
+      catch {
+        case _: Throwable => "an instance " + ofClass
+      }
   }
 
   @throws[java.io.ObjectStreamException]
   private def writeReplace(): Object = {
-    objString
+    objString: Unit
     this
   }
 

src/library/scala/Predef.scala

@@ -149,7 +149,7 @@ object Predef extends LowPriorityImplicits {
 
   // miscellaneous -----------------------------------------------------
   scala.`package`                         // to force scala package object to be seen.
-  scala.collection.immutable.List         // to force Nil, :: to be seen.
+  scala.collection.immutable.List: Unit   // to force Nil, :: to be seen.
 
   /**  @group aliases */
   type Function[-A, +B] = Function1[A, B]

src/library/scala/Symbol.scala

@@ -67,9 +67,9 @@ private[scala] abstract class UniquenessCache[K, V >: Null] {
           // wind up with one String as the key and a different String as
           // the name field in the Symbol, which can lead to surprising GC
           // behavior and duplicate Symbols. See scala/bug#6706.
-          map remove name
+          map.remove(name): Unit
           val sym = valueFromKey(name)
-          map.put(name, new WeakReference(sym))
+          map.put(name, new WeakReference(sym)): Unit
           sym
         }
       }

src/library/scala/collection/ArrayOps.scala

@@ -474,9 +474,9 @@ final class ArrayOps[A](private val xs: Array[A]) extends AnyVal {
   def partition(p: A => Boolean): (Array[A], Array[A]) = {
     val res1, res2 = ArrayBuilder.make[A]
     var i = 0
-    while(i < xs.length) {
+    while (i < xs.length) {
       val x = xs(i)
-      (if(p(x)) res1 else res2) += x
+      (if (p(x)) res1 else res2) += x
       i += 1
     }
     (res1.result(), res2.result())
@@ -506,11 +506,11 @@ final class ArrayOps[A](private val xs: Array[A]) extends AnyVal {
     val res1 = ArrayBuilder.make[A1]
     val res2 = ArrayBuilder.make[A2]
     var i = 0
-    while(i < xs.length) {
-      f(xs(i)) match {
+    while (i < xs.length) {
+      (f(xs(i)) match {
         case Left(x) => res1 += x
         case Right(x) => res2 += x
-      }
+      }): Unit
       i += 1
     }
     (res1.result(), res2.result())
@@ -1318,15 +1318,15 @@ final class ArrayOps[A](private val xs: Array[A]) extends AnyVal {
     val len = xs.length
     var i = 0
     (xs: Any @unchecked) match {
-      case xs: Array[AnyRef]  => while (i < len) { f(xs(i).asInstanceOf[A]); i = i+1 }
-      case xs: Array[Int]     => while (i < len) { f(xs(i).asInstanceOf[A]); i = i+1 }
-      case xs: Array[Double]  => while (i < len) { f(xs(i).asInstanceOf[A]); i = i+1 }
-      case xs: Array[Long]    => while (i < len) { f(xs(i).asInstanceOf[A]); i = i+1 }
-      case xs: Array[Float]   => while (i < len) { f(xs(i).asInstanceOf[A]); i = i+1 }
-      case xs: Array[Char]    => while (i < len) { f(xs(i).asInstanceOf[A]); i = i+1 }
-      case xs: Array[Byte]    => while (i < len) { f(xs(i).asInstanceOf[A]); i = i+1 }
-      case xs: Array[Short]   => while (i < len) { f(xs(i).asInstanceOf[A]); i = i+1 }
-      case xs: Array[Boolean] => while (i < len) { f(xs(i).asInstanceOf[A]); i = i+1 }
+      case xs: Array[AnyRef]  => while (i < len) { f(xs(i).asInstanceOf[A]): Unit ; i = i+1 }
+      case xs: Array[Int]     => while (i < len) { f(xs(i).asInstanceOf[A]): Unit ; i = i+1 }
+      case xs: Array[Double]  => while (i < len) { f(xs(i).asInstanceOf[A]): Unit ; i = i+1 }
+      case xs: Array[Long]    => while (i < len) { f(xs(i).asInstanceOf[A]): Unit ; i = i+1 }
+      case xs: Array[Float]   => while (i < len) { f(xs(i).asInstanceOf[A]): Unit ; i = i+1 }
+      case xs: Array[Char]    => while (i < len) { f(xs(i).asInstanceOf[A]): Unit ; i = i+1 }
+      case xs: Array[Byte]    => while (i < len) { f(xs(i).asInstanceOf[A]): Unit ; i = i+1 }
+      case xs: Array[Short]   => while (i < len) { f(xs(i).asInstanceOf[A]): Unit ; i = i+1 }
+      case xs: Array[Boolean] => while (i < len) { f(xs(i).asInstanceOf[A]): Unit ; i = i+1 }
     }
   }
 
@@ -1476,7 +1476,7 @@ final class ArrayOps[A](private val xs: Array[A]) extends AnyVal {
   /** Create a copy of this array with the specified element type. */
   def toArray[B >: A: ClassTag]: Array[B] = {
     val destination = new Array[B](xs.length)
-    copyToArray(destination, 0)
+    copyToArray(destination, 0): Unit
     destination
   }
 

src/library/scala/collection/IndexedSeqView.scala

@@ -36,7 +36,7 @@ trait IndexedSeqView[+A] extends IndexedSeqOps[A, View, View[A]] with SeqView[A]
   override def map[B](f: A => B): IndexedSeqView[B] = new IndexedSeqView.Map(this, f)
   override def reverse: IndexedSeqView[A] = new IndexedSeqView.Reverse(this)
   override def slice(from: Int, until: Int): IndexedSeqView[A] = new IndexedSeqView.Slice(this, from, until)
-  override def tapEach[U](f: A => U): IndexedSeqView[A] = new IndexedSeqView.Map(this, { (a: A) => f(a); a})
+  override def tapEach[U](f: A => U): IndexedSeqView[A] = new IndexedSeqView.Map(this, { (a: A) => f(a): Unit; a})
 
   def concat[B >: A](suffix: IndexedSeqView.SomeIndexedSeqOps[B]): IndexedSeqView[B] = new IndexedSeqView.Concat(this, suffix)
   def appendedAll[B >: A](suffix: IndexedSeqView.SomeIndexedSeqOps[B]): IndexedSeqView[B] = new IndexedSeqView.Concat(this, suffix)

src/library/scala/collection/Iterable.scala

@@ -279,7 +279,7 @@ trait IterableOps[+A, +CC[_], +C] extends Any with IterableOnce[A] with Iterable
         val it = iterator
         while (it.hasNext) {
           if (i == otherSize) return 1
-          it.next()
+          it.next(): Unit
           i += 1
         }
         i - otherSize
@@ -332,8 +332,8 @@ trait IterableOps[+A, +CC[_], +C] extends Any with IterableOnce[A] with Iterable
         val thisIt = this.iterator
         val thatIt = that.iterator
         while (thisIt.hasNext && thatIt.hasNext) {
-          thisIt.next()
-          thatIt.next()
+          thisIt.next(): Unit
+          thatIt.next(): Unit
         }
         java.lang.Boolean.compare(thisIt.hasNext, thatIt.hasNext)
       }
@@ -837,7 +837,7 @@ trait IterableOps[+A, +CC[_], +C] extends Any with IterableOnce[A] with Iterable
     */
   def inits: Iterator[C] = iterateUntilEmpty(_.init)
 
-  override def tapEach[U](f: A => U): C = fromSpecific(new View.Map(this, { (a: A) => f(a); a }))
+  override def tapEach[U](f: A => U): C = fromSpecific(new View.Map(this, { (a: A) => f(a): Unit; a }))
 
   // A helper for tails and inits.
   private[this] def iterateUntilEmpty(f: Iterable[A] => Iterable[A]): Iterator[C] = {

src/library/scala/collection/IterableOnce.scala

@@ -571,7 +571,7 @@ trait IterableOnceOps[+A, +CC[_], +C] extends Any { this: IterableOnce[A] =>
     */
   def foreach[U](f: A => U): Unit = {
     val it = iterator
-    while(it.hasNext) f(it.next())
+    while (it.hasNext) f(it.next()): Unit
   }
 
   /** Tests whether a predicate holds for all elements of this $coll.
@@ -821,7 +821,7 @@ trait IterableOnceOps[+A, +CC[_], +C] extends Any { this: IterableOnce[A] =>
     else {
       val it = iterator
       var len = 0
-      while (it.hasNext) { len += 1; it.next() }
+      while (it.hasNext) { len += 1; it.next(): Unit }
       len
     }
   }
@@ -1291,7 +1291,7 @@ trait IterableOnceOps[+A, +CC[_], +C] extends Any { this: IterableOnce[A] =>
   def toArray[B >: A: ClassTag]: Array[B] =
     if (knownSize >= 0) {
       val destination = new Array[B](knownSize)
-      copyToArray(destination, 0)
+      copyToArray(destination, 0): Unit
       destination
     }
     else mutable.ArrayBuilder.make[B].addAll(this).result()

src/library/scala/collection/Iterator.scala

@@ -449,7 +449,7 @@ trait Iterator[+A] extends IterableOnce[A] with IterableOnceOps[A, Iterator, Ite
   def indexOf[B >: A](elem: B, from: Int): Int = {
     var i = 0
     while (i < from && hasNext) {
-      next()
+      next(): Unit
       i += 1
     }
 
@@ -949,7 +949,7 @@ trait Iterator[+A] extends IterableOnce[A] with IterableOnceOps[A, Iterator, Ite
     override def hasNext = self.hasNext
     override def next() = {
       val _next = self.next()
-      f(_next)
+      f(_next): Unit
       _next
     }
   }
@@ -1223,7 +1223,7 @@ object Iterator extends IterableFactory[Iterator] {
     private def skip(): Unit =
       while (dropping > 0) {
         if (underlying.hasNext) {
-          underlying.next()
+          underlying.next(): Unit
           dropping -= 1
         } else
           dropping = 0

src/library/scala/collection/LazyZipOps.scala

@@ -109,7 +109,7 @@ final class LazyZip2[+El1, +El2, C1] private[collection](src: C1, coll1: Iterabl
     val elems1 = coll1.iterator
     val elems2 = coll2.iterator
 
-    while (elems1.hasNext && elems2.hasNext) f(elems1.next(), elems2.next())
+    while (elems1.hasNext && elems2.hasNext) f(elems1.next(), elems2.next()): Unit
   }
 
   private def toIterable: View[(El1, El2)] = new AbstractView[(El1, El2)] {
@@ -245,7 +245,7 @@ final class LazyZip3[+El1, +El2, +El3, C1] private[collection](src: C1,
     val elems3 = coll3.iterator
 
     while (elems1.hasNext && elems2.hasNext && elems3.hasNext)
-      f(elems1.next(), elems2.next(), elems3.next())
+      f(elems1.next(), elems2.next(), elems3.next()): Unit
   }
 
   private def toIterable: View[(El1, El2, El3)] = new AbstractView[(El1, El2, El3)] {
@@ -383,7 +383,7 @@ final class LazyZip4[+El1, +El2, +El3, +El4, C1] private[collection](src: C1,
     val elems4 = coll4.iterator
 
     while (elems1.hasNext && elems2.hasNext && elems3.hasNext && elems4.hasNext)
-      f(elems1.next(), elems2.next(), elems3.next(), elems4.next())
+      f(elems1.next(), elems2.next(), elems3.next(), elems4.next()): Unit
   }
 
   private def toIterable: View[(El1, El2, El3, El4)] = new AbstractView[(El1, El2, El3, El4)] {

src/library/scala/collection/Map.scala

@@ -241,7 +241,7 @@ trait MapOps[K, +V, +CC[_, _] <: IterableOps[_, AnyConstr, _], +C]
     val it = iterator
     while (it.hasNext) {
       val next = it.next()
-      f(next._1, next._2)
+      f(next._1, next._2): Unit
     }
   }
 

src/library/scala/collection/MapView.scala

@@ -146,7 +146,7 @@ object MapView extends MapViewFactory {
     override def get(key: K): Option[V] = {
       underlying.get(key) match {
         case s @ Some(v) =>
-          f((key, v))
+          f((key, v)): Unit
           s
         case None => None
       }

src/library/scala/collection/Seq.scala

@@ -723,7 +723,7 @@ trait SeqOps[+A, +CC[_], +C] extends Any
     else if (len > 1) {
       b.sizeHint(len)
       val arr = new Array[Any](len)
-      copyToArray(arr)
+      copyToArray(arr): Unit
       java.util.Arrays.sort(arr.asInstanceOf[Array[AnyRef]], ord.asInstanceOf[Ordering[AnyRef]])
       var i = 0
       while (i < len) {
@@ -892,7 +892,7 @@ trait SeqOps[+A, +CC[_], +C] extends Any
         }
         case Some(1) => None
         case Some(n) => Some(n - 1)
-      }
+      }: Unit
       include
     })
   }
@@ -917,7 +917,7 @@ trait SeqOps[+A, +CC[_], +C] extends Any
         }
         case Some(1) => None
         case Some(n) => Some(n - 1)
-      }
+      }: Unit
       include
     })
   }

src/library/scala/collection/SeqView.scala

@@ -27,7 +27,7 @@ trait SeqView[+A] extends SeqOps[A, View, View[A]] with View[A] {
   override def drop(n: Int): SeqView[A] = new SeqView.Drop(this, n)
   override def takeRight(n: Int): SeqView[A] = new SeqView.TakeRight(this, n)
   override def dropRight(n: Int): SeqView[A] = new SeqView.DropRight(this, n)
-  override def tapEach[U](f: A => U): SeqView[A] = new SeqView.Map(this, { (a: A) => f(a); a })
+  override def tapEach[U](f: A => U): SeqView[A] = new SeqView.Map(this, { (a: A) => f(a): Unit; a })
 
   def concat[B >: A](suffix: SeqView.SomeSeqOps[B]): SeqView[B] = new SeqView.Concat(this, suffix)
   def appendedAll[B >: A](suffix: SeqView.SomeSeqOps[B]): SeqView[B] = new SeqView.Concat(this, suffix)
@@ -163,7 +163,7 @@ object SeqView {
         else if (len == 1) List(underlying.head)
         else {
           val arr = new Array[Any](len) // Array[Any] =:= Array[AnyRef]
-          underlying.copyToArray(arr)
+          underlying.copyToArray(arr): Unit
           java.util.Arrays.sort(arr.asInstanceOf[Array[AnyRef]], ord.asInstanceOf[Ordering[AnyRef]])
           // casting the Array[AnyRef] to Array[A] and creating an ArraySeq from it
           // is safe because:

src/library/scala/collection/StrictOptimizedIterableOps.scala

@@ -259,8 +259,8 @@ trait StrictOptimizedIterableOps[+A, +CC[_], +C]
     val lead = iterator drop n
     val it = iterator
     while (lead.hasNext) {
-      lead.next()
-      it.next()
+      lead.next(): Unit
+      it.next(): Unit
     }
     while (it.hasNext) b += it.next()
     b.result()
@@ -277,7 +277,7 @@ trait StrictOptimizedIterableOps[+A, +CC[_], +C]
     val it = iterator
     while (lead.hasNext) {
       b += it.next()
-      lead.next()
+      lead.next(): Unit
     }
     b.result()
   }

src/library/scala/collection/StringOps.scala

@@ -1034,7 +1034,7 @@ final class StringOps(private val s: String) extends AnyVal {
     val len = s.length
     var i = 0
     while(i < len) {
-      f(s.charAt(i))
+      f(s.charAt(i)): Unit
       i += 1
     }
   }
@@ -1437,8 +1437,8 @@ final class StringOps(private val s: String) extends AnyVal {
     val len = s.length
     while(i < len) {
       f(s.charAt(i)) match {
-        case Left(c) => res1.append(c)
-        case Right(c) => res2.append(c)
+        case Left(c) => res1.append(c): Unit
+        case Right(c) => res2.append(c): Unit
       }
       i += 1
     }