diff options
Diffstat (limited to 'src/dotty/tools/dotc/ast/Trees.scala')
| -rw-r--r-- | src/dotty/tools/dotc/ast/Trees.scala | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/src/dotty/tools/dotc/ast/Trees.scala b/src/dotty/tools/dotc/ast/Trees.scala index 2392e52be..628e7f9d3 100644 --- a/src/dotty/tools/dotc/ast/Trees.scala +++ b/src/dotty/tools/dotc/ast/Trees.scala @@ -156,7 +156,12 @@ object Trees { private[this] var myTpe: T = _ - private def setMyTpe(tpe: T) = myTpe = tpe + /** Destructively set the type of the tree. This should be called only when it is known that + * it is safe under sharing to do so. One user-case is in the withType method below + * which implements copy-on-write. Another user-case is in method interpolateAndAdapt in Typer, + * where we overwrite with a simplified version of the type itself. + */ + private[dotc] def overwriteType(tpe: T) = myTpe = tpe /** The type of the tree. In case of an untyped tree, * an UnAssignedTypeException is thrown. (Overridden by empty trees) @@ -191,7 +196,7 @@ object Trees { (if (myTpe == null || (myTpe.asInstanceOf[AnyRef] eq tpe.asInstanceOf[AnyRef])) this else clone).asInstanceOf[Tree[Type]] - tree setMyTpe tpe + tree overwriteType tpe tree.asInstanceOf[ThisTree[Type]] } |