reimplement '/home/humza/Downloads/sml/shf/todo.md' motion so that it has the same behaviour as Vim. (If the cursor is not at a pair character, then check after the cursor to see if we find a pair-character there. If some location after the cursor has a pair-character, then move the cursor to it and find the pair of the character, if any.)

fcore/cursor.sml

@@ -209,14 +209,47 @@ struct
 
   val toPrevChr = ToPrevChr.foldPrev
 
+  structure NextPairChr =
+    MakeIfCharFolderNext
+      (struct
+         type env = unit
+
+        fun isPairChr chr =
+          chr = #"(" orelse chr = #")" orelse 
+          chr = #"[" orelse chr = #"]" orelse
+          chr = #"{" orelse chr = #"}" orelse
+          chr = #"<" orelse chr = #">"
+
+        fun loop (strPos, str, absIdx, stl) =
+          if strPos = String.size str then
+            case stl of
+              str :: stl => loop (0, str, absIdx, stl)
+            | [] => ~1
+          else
+            let
+              val chr = String.sub (str, strPos)
+            in
+              if isPairChr chr then
+                absIdx
+              else
+                loop (strPos + 1, str, absIdx + 1, stl)
+            end
+
+         fun fStart (strPos, str, _, absIdx, stl, _, _) =
+           loop (strPos, str, absIdx, stl)
+       end)
+
+  fun nextPairChr (lineGap, cursorIdx) =
+    NextPairChr.foldNext (lineGap, cursorIdx, ())
+
   fun helpMatchPairNext
-    (strPos, str, absIdx, stl, origIdx, openChr, openNum, closeChr, closeNum) =
+    (strPos, str, absIdx, stl, openChr, openNum, closeChr, closeNum) =
     if strPos = String.size str then
       case stl of
         hd :: tl =>
           helpMatchPairNext
-            (0, hd, absIdx, tl, origIdx, openChr, openNum, closeChr, closeNum)
+            (0, hd, absIdx, tl, openChr, openNum, closeChr, closeNum)
-      | [] => origIdx
+      | [] => ~1
     else
       let
         val chr = String.sub (str, strPos)
@@ -231,7 +264,6 @@ struct
             , str
             , absIdx + 1
             , stl
-            , origIdx
             , openChr
             , openNum
             , closeChr
@@ -240,7 +272,7 @@ struct
       end
 
   fun helpMatchPairPrev
-    (strPos, str, absIdx, stl, origIdx, openChr, openNum, closeChr, closeNum) =
+    (strPos, str, absIdx, stl, openChr, openNum, closeChr, closeNum) =
     if strPos < 0 then
       case stl of
         hd :: tl =>
@@ -249,13 +281,12 @@ struct
             , hd
             , absIdx
             , tl
-            , origIdx
             , openChr
             , openNum
             , closeChr
             , closeNum
             )
-      | [] => origIdx
+      | [] => ~1
     else
       let
         val chr = String.sub (str, strPos)
@@ -270,7 +301,6 @@ struct
             , str
             , absIdx - 1
             , stl
-            , origIdx
             , openChr
             , openNum
             , closeChr
@@ -286,7 +316,6 @@ struct
           , shd
           , cursorIdx + 1
           , rightStrings
-          , cursorIdx
           , #"("
           , 1
           , #")"
@@ -298,7 +327,6 @@ struct
           , shd
           , cursorIdx - 1
           , leftStrings
-          , cursorIdx
           , #"("
           , 0
           , #")"
@@ -310,7 +338,6 @@ struct
           , shd
           , cursorIdx + 1
           , rightStrings
-          , cursorIdx
           , #"["
           , 1
           , #"]"
@@ -322,7 +349,6 @@ struct
           , shd
           , cursorIdx - 1
           , leftStrings
-          , cursorIdx
           , #"["
           , 0
           , #"]"
@@ -334,7 +360,6 @@ struct
           , shd
           , cursorIdx + 1
           , rightStrings
-          , cursorIdx
           , #"{"
           , 1
           , #"}"
@@ -346,7 +371,6 @@ struct
           , shd
           , cursorIdx - 1
           , leftStrings
-          , cursorIdx
           , #"{"
           , 0
           , #"}"
@@ -358,7 +382,6 @@ struct
           , shd
           , cursorIdx + 1
           , rightStrings
-          , cursorIdx
           , #"<"
           , 1
           , #">"
@@ -370,13 +393,12 @@ struct
           , shd
           , cursorIdx - 1
           , leftStrings
-          , cursorIdx
           , #"<"
           , 0
           , #">"
           , 1
           )
-    | _ => cursorIdx
+    | _ => ~1
 
   fun matchPair (lineGap: LineGap.t, cursorIdx) =
     let

fcore/normal-mode/normal-move.sml

@@ -398,46 +398,57 @@ struct
 
       (* move LineGap and buffer to start of line *)
       val buffer = LineGap.goToIdx (cursorIdx, buffer)
-      val cursorIdx = Cursor.matchPair (buffer, cursorIdx)
+      val cursorIdx = Cursor.nextPairChr (buffer, cursorIdx)
     in
-      let
+      if cursorIdx = ~1 then
-        val buffer = LineGap.goToIdx (cursorIdx, buffer)
+        NormalFinish.clearMode app
-        val visualScrollColumn =
+      else
-          TextScroll.getScrollColumn
+        let
-            (buffer, cursorIdx, windowWidth, prevScrollColumn)
+          val buffer = LineGap.goToIdx (cursorIdx, buffer)
+          val cursorIdx = Cursor.matchPair (buffer, cursorIdx)
+        in
+          if cursorIdx = ~1 then
+            NormalFinish.clearMode app
+          else
+            let
+              val buffer = LineGap.goToIdx (cursorIdx, buffer)
+              val visualScrollColumn =
+                TextScroll.getScrollColumn
+                  (buffer, cursorIdx, windowWidth, prevScrollColumn)
 
-        val cursorLine = LineGap.idxToLineNumber (cursorIdx, buffer)
+              val cursorLine = LineGap.idxToLineNumber (cursorIdx, buffer)
-        val startLine =
+              val startLine =
-          TextScroll.getStartLine
+                TextScroll.getStartLine
-            (prevLineNumber, cursorLine, windowHeight, #lineLength buffer)
+                  (prevLineNumber, cursorLine, windowHeight, #lineLength buffer)
 
-        val buffer = LineGap.goToLine (startLine, buffer)
+              val buffer = LineGap.goToLine (startLine, buffer)
 
-        val drawMsg = NormalModeTextBuilder.build
+              val drawMsg = NormalModeTextBuilder.build
-          ( startLine
+                ( startLine
-          , cursorIdx
+                , cursorIdx
-          , buffer
+                , buffer
-          , windowWidth
+                , windowWidth
-          , windowHeight
+                , windowHeight
-          , searchList
+                , searchList
-          , visualScrollColumn
+                , visualScrollColumn
-          )
+                )
-        val drawMsg = Vector.concat drawMsg
+              val drawMsg = Vector.concat drawMsg
-        val drawMsg = DrawMsg.DRAW_TEXT drawMsg
+              val drawMsg = DrawMsg.DRAW_TEXT drawMsg
-        val drawMsg = [MailboxType.DRAW drawMsg]
+              val drawMsg = [MailboxType.DRAW drawMsg]
-      in
+            in
-        NormalModeWith.bufferAndCursorIdx
+              NormalModeWith.bufferAndCursorIdx
-          ( app
+                ( app
-          , buffer
+                , buffer
-          , cursorIdx
+                , cursorIdx
-          , NORMAL_MODE ""
+                , NORMAL_MODE ""
-          , startLine
+                , startLine
-          , searchList
+                , searchList
-          , drawMsg
+                , drawMsg
-          , bufferModifyTime
+                , bufferModifyTime
-          , visualScrollColumn
+                , visualScrollColumn
-          )
+                )
-      end
+            end
+        end
     end
 
   fun firstNonSpaceChr (app: app_type) =

temp.txt

@@ -1,3 +1 @@
-hello
+he()o world
-world
-again

test/normal-move.sml

@@ -1752,21 +1752,39 @@ struct
           (* assert *)
           Expect.isTrue (getChr app = #"<")
         end)
-    (* testing that % on a non-pair character is a no-op *)
+    , test
-    , test "does not move when cursor is on a non-pair-character" (fn _ =>
+        "does not move when cursor is on a non-pair-character, \
-        let
+        \and there is no pair-character where the cursor is at or after the cursor"
-          (* arrange *)
+        (fn _ =>
-          val app = TestUtils.init "hello, world\n"
+           let
-          val app = AppWith.idx (app, 5)
+             (* arrange *)
-          val oldIdx = #cursorIdx app
+             val app = TestUtils.init "he()o, world\n"
+             val app = AppWith.idx (app, 5)
+             val oldIdx = #cursorIdx app
 
-          (* act *)
+             (* act *)
-          val app = TestUtils.update (app, CHAR_EVENT #"%")
+             val app = TestUtils.update (app, CHAR_EVENT #"%")
-          val newIdx = #cursorIdx app
+             val newIdx = #cursorIdx app
-        in
+           in
-          (* assert *)
+             (* assert *)
-          Expect.isTrue (newIdx = oldIdx)
+             Expect.isTrue (newIdx = oldIdx)
-        end)
+           end)
+    , test
+        "moves cursor when the cursor is not on a \
+        \pair-character, but there is a pair-character \
+        \after the cursor"
+        (fn _ =>
+           let
+             (* arrange *)
+             val app = TestUtils.init "he()o world\n"
+             val app = AppWith.idx (app, 0)
+
+             (* act *)
+             val {cursorIdx, ...} = TestUtils.update (app, CHAR_EVENT #"%")
+           in
+             (* assert *)
+             Expect.isTrue (cursorIdx = 3)
+           end)
     ]
 
   (* movements which use multiple chars *)

todo.md

@@ -1,8 +1,8 @@
 # To-do list
 
 - Add tests for:
-- Reimplement `%` motion and `d%` motion.
+- Reimplement `d%` motion.
-  - They should both search for the next character in any pair, the same way in Vim
+  - It should both search for the next character in any pair, the same way in Vim
   - Add tests for reimplemented movements and motions
 - Reimplement `di<symbol>` and `da<symbol>`
   - They should search for the next char in the specific pair, the same way in Vim