Merge pull request #6994 from dotty-staging/drop-do-while

Drop do while

Author: odersky

community-build/community-projects/stdLib213

@@ -719,14 +719,15 @@ abstract class BTypes {
       var chainA = as
       var chainB = bs
       var fcs: ClassBType = null
-      do {
+      while {
         if      (chainB contains chainA.head) fcs = chainA.head
         else if (chainA contains chainB.head) fcs = chainB.head
         else {
           chainA = chainA.tail
           chainB = chainB.tail
         }
-      } while (fcs == null)
+        fcs == null
+      } do ()
       fcs
     }
 

compiler/src/dotty/tools/backend/jvm/BTypes.scala

@@ -1569,10 +1569,6 @@ object desugar {
       case PrefixOp(op, t) =>
         val nspace = if (ctx.mode.is(Mode.Type)) tpnme else nme
         Select(t, nspace.UNARY_PREFIX ++ op.name)
-      case DoWhile(body, cond) =>
-        // while ({ { body }; { cond } }) { () }
-        // the inner blocks are there to protect the scopes of body and cond from each other
-        WhileDo(Block(Block(Nil, body), Block(Nil, cond)), Literal(Constant(())))
       case ForDo(enums, body) =>
         makeFor(nme.foreach, nme.foreach, enums, body) orElse tree
       case ForYield(enums, body) =>

compiler/src/dotty/tools/dotc/ast/Desugar.scala

@@ -102,7 +102,6 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
   case class Quote(quoted: Tree)(implicit @constructorOnly src: SourceFile) extends TermTree
   case class Splice(expr: Tree)(implicit @constructorOnly src: SourceFile) extends TermTree
   case class TypSplice(expr: Tree)(implicit @constructorOnly src: SourceFile) extends TypTree
-  case class DoWhile(body: Tree, cond: Tree)(implicit @constructorOnly src: SourceFile) extends TermTree
   case class ForYield(enums: List[Tree], expr: Tree)(implicit @constructorOnly src: SourceFile) extends TermTree
   case class ForDo(enums: List[Tree], body: Tree)(implicit @constructorOnly src: SourceFile) extends TermTree
   case class GenFrom(pat: Tree, expr: Tree, checkMode: GenCheckMode)(implicit @constructorOnly src: SourceFile) extends Tree
@@ -532,10 +531,6 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
       case tree: TypSplice if expr eq tree.expr => tree
       case _ => finalize(tree, untpd.TypSplice(expr)(tree.source))
     }
-    def DoWhile(tree: Tree)(body: Tree, cond: Tree)(implicit ctx: Context): TermTree = tree match {
-      case tree: DoWhile if (body eq tree.body) && (cond eq tree.cond) => tree
-      case _ => finalize(tree, untpd.DoWhile(body, cond)(tree.source))
-    }
     def ForYield(tree: Tree)(enums: List[Tree], expr: Tree)(implicit ctx: Context): TermTree = tree match {
       case tree: ForYield if (enums eq tree.enums) && (expr eq tree.expr) => tree
       case _ => finalize(tree, untpd.ForYield(enums, expr)(tree.source))
@@ -604,8 +599,6 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
         cpy.Splice(tree)(transform(expr))
       case TypSplice(expr) =>
         cpy.TypSplice(tree)(transform(expr))
-      case DoWhile(body, cond) =>
-        cpy.DoWhile(tree)(transform(body), transform(cond))
       case ForYield(enums, expr) =>
         cpy.ForYield(tree)(transform(enums), transform(expr))
       case ForDo(enums, body) =>
@@ -661,8 +654,6 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
         this(x, expr)
       case TypSplice(expr) =>
         this(x, expr)
-      case DoWhile(body, cond) =>
-        this(this(x, body), cond)
       case ForYield(enums, expr) =>
         this(this(x, enums), expr)
       case ForDo(enums, body) =>

compiler/src/dotty/tools/dotc/ast/untpd.scala

@@ -802,11 +802,11 @@ object Denotations {
     def history: List[SingleDenotation] = {
       val b = new ListBuffer[SingleDenotation]
       var current = initial
-      do {
+      while {
         b += (current)
         current = current.nextInRun
-      }
-      while (current ne initial)
+        current ne initial
+      } do ()
       b.toList
     }
 
@@ -820,11 +820,12 @@ object Denotations {
         symbol.is(Permanent),              // Permanent symbols are valid in all runIds
         s"denotation $this invalid in run ${ctx.runId}. ValidFor: $validFor")
       var d: SingleDenotation = this
-      do {
+      while {
         d.validFor = Period(ctx.period.runId, d.validFor.firstPhaseId, d.validFor.lastPhaseId)
         d.invalidateInheritedInfo()
         d = d.nextInRun
-      } while (d ne this)
+        d ne this
+      } do ()
       this
     }
 
@@ -1053,12 +1054,13 @@ object Denotations {
       var cur = this
       var cnt = 0
       var interval = validFor
-      do {
+      while {
         cur = cur.nextInRun
         cnt += 1
         assert(cnt <= MaxPossiblePhaseId, demandOutsideDefinedMsg)
         interval |= cur.validFor
-      } while (cur ne this)
+        cur ne this
+      } do ()
       interval
     }
 
@@ -1075,12 +1077,13 @@ object Denotations {
       var sb = new StringBuilder()
       var cur = this
       var cnt = 0
-      do {
+      while {
         sb.append(" " + cur.validFor)
         cur = cur.nextInRun
         cnt += 1
         if (cnt > MaxPossiblePhaseId) { sb.append(" ..."); cur = this }
-      } while (cur ne this)
+        cur ne this
+      } do ()
       sb.toString
     }
 

compiler/src/dotty/tools/dotc/core/Denotations.scala

@@ -382,9 +382,9 @@ object Scopes {
     override final def lookupNextEntry(entry: ScopeEntry)(implicit ctx: Context): ScopeEntry = {
       var e = entry
       if (hashTable ne null)
-        do { e = e.tail } while ((e ne null) && e.name != entry.name)
+        while ({ e = e.tail ; (e ne null) && e.name != entry.name }) ()
       else
-        do { e = e.prev } while ((e ne null) && e.name != entry.name)
+        while ({ e = e.prev ; (e ne null) && e.name != entry.name }) ()
       e
     }
 

compiler/src/dotty/tools/dotc/core/Scopes.scala

@@ -149,11 +149,12 @@ class TastyBuffer(initialSize: Int) {
     var b = 0L
     var x = 0L
     var idx = at.index
-    do {
+    while {
       b = bytes(idx)
       x = (x << 7) | (b & 0x7f)
       idx += 1
-    } while ((b & 0x80) == 0)
+      (b & 0x80) == 0
+    } do ()
     x
   }
 

compiler/src/dotty/tools/dotc/core/tasty/TastyBuffer.scala

@@ -75,11 +75,12 @@ class TastyReader(val bytes: Array[Byte], start: Int, end: Int, val base: Int =
   def readLongNat(): Long = {
     var b = 0L
     var x = 0L
-    do {
+    while {
       b = bytes(bp)
       x = (x << 7) | (b & 0x7f)
       bp += 1
-    } while ((b & 0x80) == 0)
+      (b & 0x80) == 0
+    } do ()
     x
   }
 

compiler/src/dotty/tools/dotc/core/tasty/TastyReader.scala

@@ -175,10 +175,11 @@ class TreeBuffer extends TastyBuffer(50000) {
     //println(s"offsets: ${offsets.take(numOffsets).deep}")
     //println(s"deltas: ${delta.take(numOffsets).deep}")
     var saved = 0
-    do {
+    while {
       saved = adjustDeltas()
       pickling.println(s"adjusting deltas, saved = $saved")
-    } while (saved > 0 && length / saved < 100)
+      saved > 0 && length / saved < 100
+    } do ()
     adjustOffsets()
     adjustTreeAddrs()
     val wasted = compress()

compiler/src/dotty/tools/dotc/core/tasty/TreeBuffer.scala

@@ -107,10 +107,11 @@ class PickleBuffer(data: Array[Byte], from: Int, to: Int) {
   def readLongNat(): Long = {
     var b = 0L
     var x = 0L
-    do {
+    while ({
       b = readByte()
       x = (x << 7) + (b & 0x7f)
-    } while ((b & 0x80) != 0L)
+      (b & 0x80) != 0L
+    }) ()
     x
   }