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.)

2026-01-01 06:58:30 +00:00
parent a65b950b77
commit 44dbe1ffb0
5 changed files with 121 additions and 72 deletions
--- a/fcore/cursor.sml
+++ b/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)
-      | [] => origIdx
+            (0, hd, absIdx, tl, openChr, openNum, closeChr, closeNum)
+      | [] => ~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
--- a/fcore/normal-mode/normal-move.sml
+++ b/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
-        val buffer = LineGap.goToIdx (cursorIdx, buffer)
-        val visualScrollColumn =
-          TextScroll.getScrollColumn
-            (buffer, cursorIdx, windowWidth, prevScrollColumn)
+      if cursorIdx = ~1 then
+        NormalFinish.clearMode app
+      else
+        let
+          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 startLine =
-          TextScroll.getStartLine
-            (prevLineNumber, cursorLine, windowHeight, #lineLength buffer)
+              val cursorLine = LineGap.idxToLineNumber (cursorIdx, buffer)
+              val startLine =
+                TextScroll.getStartLine
+                  (prevLineNumber, cursorLine, windowHeight, #lineLength buffer)

-        val buffer = LineGap.goToLine (startLine, buffer)
+              val buffer = LineGap.goToLine (startLine, buffer)

-        val drawMsg = NormalModeTextBuilder.build
-          ( startLine
-          , cursorIdx
-          , buffer
-          , windowWidth
-          , windowHeight
-          , searchList
-          , visualScrollColumn
-          )
-        val drawMsg = Vector.concat drawMsg
-        val drawMsg = DrawMsg.DRAW_TEXT drawMsg
-        val drawMsg = [MailboxType.DRAW drawMsg]
-      in
-        NormalModeWith.bufferAndCursorIdx
-          ( app
-          , buffer
-          , cursorIdx
-          , NORMAL_MODE ""
-          , startLine
-          , searchList
-          , drawMsg
-          , bufferModifyTime
-          , visualScrollColumn
-          )
-      end
+              val drawMsg = NormalModeTextBuilder.build
+                ( startLine
+                , cursorIdx
+                , buffer
+                , windowWidth
+                , windowHeight
+                , searchList
+                , visualScrollColumn
+                )
+              val drawMsg = Vector.concat drawMsg
+              val drawMsg = DrawMsg.DRAW_TEXT drawMsg
+              val drawMsg = [MailboxType.DRAW drawMsg]
+            in
+              NormalModeWith.bufferAndCursorIdx
+                ( app
+                , buffer
+                , cursorIdx
+                , NORMAL_MODE ""
+                , startLine
+                , searchList
+                , drawMsg
+                , bufferModifyTime
+                , visualScrollColumn
+                )
+            end
+        end
    end

  fun firstNonSpaceChr (app: app_type) =
--- a/temp.txt
+++ b/temp.txt
@@ -1,3 +1 @@
-hello
-world
-again
+he()o world
--- a/test/normal-move.sml
+++ b/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 "does not move when cursor is on a non-pair-character" (fn _ =>
-        let
-          (* arrange *)
-          val app = TestUtils.init "hello, world\n"
-          val app = AppWith.idx (app, 5)
-          val oldIdx = #cursorIdx app
+    , test
+        "does not move when cursor is on a non-pair-character, \
+        \and there is no pair-character where the cursor is at or after the cursor"
+        (fn _ =>
+           let
+             (* arrange *)
+             val app = TestUtils.init "he()o, world\n"
+             val app = AppWith.idx (app, 5)
+             val oldIdx = #cursorIdx app

-          (* act *)
-          val app = TestUtils.update (app, CHAR_EVENT #"%")
-          val newIdx = #cursorIdx app
-        in
-          (* assert *)
-          Expect.isTrue (newIdx = oldIdx)
-        end)
+             (* act *)
+             val app = TestUtils.update (app, CHAR_EVENT #"%")
+             val newIdx = #cursorIdx app
+           in
+             (* assert *)
+             Expect.isTrue (newIdx = oldIdx)
+           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 *)
--- a/todo.md
+++ b/todo.md
@@ -1,8 +1,8 @@
 # To-do list

 - Add tests for:
- Reimplement `%` motion and `d%` motion.
-  - They should both search for the next character in any pair, the same way in Vim
+- Reimplement `d%` motion.
+  - 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