fix broken up/down selection

src/core/editor/Move.re

@@ -12,13 +12,17 @@ type t =
 
 // bounds goal pos to within start/end pos of program.
 // returns none if the resulting goal pos is same as start pos.
-let map_focus = (f: Loc.t => Loc.t, z: Zipper.t): option(Zipper.t) => {
+let map_focus =
+    (~drop_anchor=false, f: Loc.t => Loc.t, z: Zipper.t): option(Zipper.t) => {
   open Options.Syntax;
   let c = Zipper.zip(~save_cursor=true, z);
   let* init = Option.bind(c.marks.cursor, Path.Cursor.get_focus);
   let goal = Layout.map(~tree=Layout.mk_cell(c), f, init);
   goal == init
-    ? None : c |> Cell.map_marks(Cell.Marks.put_focus(goal)) |> Zipper.unzip;
+    ? None
+    : c
+      |> Cell.map_marks(Cell.Marks.put_focus(~drop_anchor, goal))
+      |> Zipper.unzip;
 };
 
 // returns token with updated cursor after moving in direction d.
@@ -97,11 +101,13 @@ let rec hstep_n = (n: int, z: Zipper.t): Zipper.t => {
   };
 };
 
-let vstep = (d: Dir.t) =>
-  map_focus(loc => {...loc, row: loc.row + Dir.pick(d, ((-1), 1))});
+let vstep = (~drop_anchor=false, d: Dir.t) =>
+  map_focus(~drop_anchor, loc =>
+    {...loc, row: loc.row + Dir.pick(d, ((-1), 1))}
+  );
 
-let skip = (d2: Dir2.t) =>
-  map_focus(loc =>
+let skip = (~drop_anchor=false, d2: Dir2.t) =>
+  map_focus(~drop_anchor, loc =>
     switch (d2) {
     | H(L) => {...loc, col: 0}
     | H(R) => {...loc, col: Int.max_int}
@@ -110,7 +116,8 @@ let skip = (d2: Dir2.t) =>
     }
   );
 
-let jump = loc => map_focus(Fun.const(loc));
+let jump = (~drop_anchor=false, loc) =>
+  map_focus(~drop_anchor, Fun.const(loc));
 
 // todo: need to return none in some more cases when no visible movement occurs
 let perform =

src/core/editor/Select.re

@@ -167,8 +167,8 @@ let perform = (a: t, z: Zipper.t): option(Zipper.t) =>
   | Move(a) =>
     switch (a) {
     | Step(H(d)) => hstep(d, z)
-    | Step(V(d)) => Move.vstep(d, z)
-    | Skip(d2) => Move.skip(d2, z)
-    | Jump(pos) => Move.jump(pos, z)
+    | Step(V(d)) => Move.vstep(~drop_anchor=true, d, z)
+    | Skip(d2) => Move.skip(~drop_anchor=true, d2, z)
+    | Jump(pos) => Move.jump(~drop_anchor=true, pos, z)
     }
   };

src/core/structure/marks/Marks.re

@@ -84,9 +84,27 @@ module Cell = {
   let put_cursor = (cur, marks) => {...marks, cursor: Some(cur)};
   let get_focus = (marks: t) =>
     Option.bind(marks.cursor, Path.Cursor.get_focus);
-  let put_focus = (path: Path.t, marks: t) => {
+  // let map_focus = (marks: t) => Path.Cursor.get_focus(marks.cursor);
+  let put_focus = (~drop_anchor=false, foc: Path.t, marks: t) => {
     ...marks,
-    cursor: Path.Cursor.put_focus(path, marks.cursor),
+    cursor: {
+      open Options.Syntax;
+      let/ () = {
+        let* () = Options.of_bool(drop_anchor);
+        let* cur = marks.cursor;
+        // only drop anchor if cursor was pointing
+        let* car = Cursor.get_point(cur);
+        let+ sel =
+          Result.to_option(
+            Path.Selection.of_carets(
+              Caret.focus(foc),
+              Caret.anchor(car.path),
+            ),
+          );
+        Path.Cursor.select(sel);
+      };
+      Path.Cursor.put_focus(foc, marks.cursor);
+    },
   };
 
   let add_oblig = (~path=Path.empty, t: Mtrl.T.t, marks: t) => {

src/web/view/Code.re

@@ -73,10 +73,10 @@ let cursor = (~font, z: Zipper.t) => {
 };
 
 let view = (~font: Model.Font.t, ~zipper: Zipper.t): Node.t => {
-  // print_endline("--- Code.view ---");
-  // print_endline("z = " ++ Zipper.show(zipper));
+  // P.log("--- Code.view ---");
+  // P.show("z", Zipper.show(zipper));
   let c = Zipper.zip(~save_cursor=true, zipper);
-  // print_endline("c = " ++ Cell.show(c));
+  // P.show("c", Cell.show(c));
   // let t = Layout.mk_cell(c);
   // print_endline("t = " ++ LCell.show(t));
   // let b = LCell.flatten(t);