diff options
Diffstat (limited to 'src/compiler/scala/reflect/internal/Positions.scala')
| -rw-r--r-- | src/compiler/scala/reflect/internal/Positions.scala | 38 |
1 files changed, 35 insertions, 3 deletions
diff --git a/src/compiler/scala/reflect/internal/Positions.scala b/src/compiler/scala/reflect/internal/Positions.scala index 78de8d0ff2..5ec2659098 100644 --- a/src/compiler/scala/reflect/internal/Positions.scala +++ b/src/compiler/scala/reflect/internal/Positions.scala @@ -3,9 +3,8 @@ package internal trait Positions extends api.Positions { self: SymbolTable => - def focusPos(pos: Position): Position - def isRangePos(pos: Position): Boolean - def showPos(pos: Position): String + type Position = scala.tools.nsc.util.Position + val NoPosition = scala.tools.nsc.util.NoPosition /** A position that wraps a set of trees. * The point of the wrapping position is the point of the default position. @@ -27,4 +26,37 @@ trait Positions extends api.Positions { self: SymbolTable => * to some of the nodes in `tree`. */ def ensureNonOverlapping(tree: Tree, others: List[Tree]) {} + + trait PosAssigner extends Traverser { + var pos: Position + } + protected[this] lazy val posAssigner: PosAssigner = new DefaultPosAssigner + + protected class DefaultPosAssigner extends PosAssigner { + var pos: Position = _ + override def traverse(t: Tree) { + if (t eq EmptyTree) () + else if (t.pos == NoPosition) { + t.setPos(pos) + super.traverse(t) // TODO: bug? shouldn't the traverse be outside of the if? + // @PP: it's pruning whenever it encounters a node with a + // position, which I interpret to mean that (in the author's + // mind at least) either the children of a positioned node will + // already be positioned, or the children of a positioned node + // do not merit positioning. + // + // Whatever the author's rationale, it does seem like a bad idea + // to press on through a positioned node to find unpositioned + // children beneath it and then to assign whatever happens to + // be in `pos` to such nodes. There are supposed to be some + // position invariants which I can't imagine surviving that. + } + } + } + + def atPos[T <: Tree](pos: Position)(tree: T): T = { + posAssigner.pos = pos + posAssigner.traverse(tree) + tree + } }
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