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|
(* Bug found. Final references for the inner loop were being processed in the wrong order. *)
PolyML.Compiler.maxInlineSize := 40;
type location = { startPosition: int, endPosition: int };
datatype ptProperties =
PTprint of string
| PTparent of unit -> exportTree
| PTpreviousSibling of unit -> exportTree
| PTnextSibling of unit -> exportTree
| PTfirstChild of unit -> exportTree
withtype exportTree = location * ptProperties list
datatype direction = Up | Down | Left | Right;
fun find([], _) = NONE (* No change *)
| find(PTparent p :: _, Up) = SOME p
| find(PTpreviousSibling p :: _, Left) = SOME p
| find(PTnextSibling p :: _, Right) = SOME p
| find(PTfirstChild p :: _, Down) = SOME p
| find(_ :: tl, dir) = find (tl, dir);
fun navigateTo(searchLocation as {startOffset, endOffset}, lastParsetree as ({ startPosition, endPosition, ... }, tree)) =
if startOffset = startPosition andalso endOffset = endPosition
then (* We're there already. *) lastParsetree
else if startOffset >= startPosition andalso endOffset <= endPosition
then (* It's this node or a child. *)
let
val child = find(tree, Down)
in
(* See if the element we want is actually a child. *)
case child of
SOME child =>
let
(* See which child it is. *)
fun findChild(location as {startPosition, endPosition, ...}, child) =
if startOffset >= startPosition andalso endOffset <= endPosition
then SOME (location, child)
else
case find(child, Right) of
NONE => NONE
| SOME next => findChild(next())
in
case findChild(child()) of
NONE => lastParsetree (* In this *)
| SOME child => navigateTo(searchLocation, child)
end
| NONE => lastParsetree (* No children. *)
end
else raise Fail "bad";
fun pos(s, e) = {startPosition=s, endPosition=e}: location;
val n1 = (pos(1, 2), [PTprint("a")]);
val n2 = (pos(3, 4), [PTprint("b"), PTnextSibling(fn () => n1)]);
val n3 = (pos(1, 4), [PTprint("c"), PTfirstChild(fn()=>n2)]);
case navigateTo({startOffset=1, endOffset=1}, n3) of
({endPosition = 2, startPosition = 1}, [PTprint "a"]) => ()
| _ => raise Fail "bad";
|
