From d135526386a11106e4f483b29277ec989b5394c8 Mon Sep 17 00:00:00 2001
From: Humza Shahid <humzasaur@gmail.com>
Date: Tue, 2 Sep 2025 12:33:02 +0100
Subject: [PATCH] refactoring, and fix bug in 'y^' motion. (When cursor is
 after first-non-space-character, copy from first-non-space-character to
 cursor. Otherwise, copy spaces at beginning until first-non-space-character.)

---
 fcore/normal-mode/normal-mode.sml | 88 +++++++++++++++----------------
 fcore/normal-mode/normal-yank.sml | 87 ++++++++++++++++++++++++++++++
 shf.mlb                           |  1 +
 3 files changed, 131 insertions(+), 45 deletions(-)
 create mode 100644 fcore/normal-mode/normal-yank.sml

diff --git a/fcore/normal-mode/normal-mode.sml b/fcore/normal-mode/normal-mode.sml
index ec71bec..8642b50 100644
--- a/fcore/normal-mode/normal-mode.sml
+++ b/fcore/normal-mode/normal-mode.sml
@@ -241,40 +241,21 @@ struct
 
   fun parseYankTerminal (str, count, app, chrCmd, time) =
     case chrCmd of
-      #"y" =>
-        let
-          open DrawMsg
-          open MailboxType
-
-          val {buffer, cursorIdx, ...} = app
-
-          val buffer = LineGap.goToIdx (cursorIdx, buffer)
-          val low = Cursor.vi0 (buffer, cursorIdx)
-
-          val buffer = LineGap.goToIdx (low, buffer)
-          val high = Cursor.viDlrForDelete (buffer, low, 1)
-
-          val buffer = LineGap.goToIdx (high, buffer)
-          val length = high - low
-          val str = LineGap.substring (low, length, buffer)
-
-          val msg = YANK str
-          val mode = NORMAL_MODE ""
-        in
-          NormalModeWith.modeAndBuffer (app, buffer, mode, [DRAW msg])
-        end
-    | #"0" =>
-        let val f = fn (buffer, cursorIdx, _) => Cursor.vi0 (buffer, cursorIdx)
-        in yankWhenMovingBack (app, f, 1)
-        end
-    | #"w" => yankWhenMovingForward (app, Cursor.nextWord, count)
-    | #"W" => yankWhenMovingForward (app, Cursor.nextWORD, count)
-    | #"b" => yankWhenMovingBack (app, Cursor.prevWord, count)
-    | #"B" => yankWhenMovingBack (app, Cursor.prevWORD, count)
-    | #"e" => yankWhenMovingForward (app, Cursor.endOfWordForDelete, count)
-    | #"E" => yankWhenMovingForward (app, Cursor.endOfWORDForDelete, count)
-
-    | #"$" => yankWhenMovingForward (app, Cursor.viDlr, 1)
+    (* motions like yh / yj / yk / yl are not really needed.
+     * Vim supports them, but I never use them.
+     * I also don't need yx (yank a character and then remove it)
+     * because I never do that. *)
+      #"y" => NormalYank.yankLine (app, count)
+    | #"0" => NormalYank.yankToStartOfLine app
+    | #"w" => NormalYank.yankWhenMovingForward (app, Cursor.nextWord, count)
+    | #"W" => NormalYank.yankWhenMovingForward (app, Cursor.nextWORD, count)
+    | #"b" => NormalYank.yankWhenMovingBack (app, Cursor.prevWord, count)
+    | #"B" => NormalYank.yankWhenMovingBack (app, Cursor.prevWORD, count)
+    | #"e" =>
+        NormalYank.yankWhenMovingForward (app, Cursor.endOfWordForDelete, count)
+    | #"E" =>
+        NormalYank.yankWhenMovingForward (app, Cursor.endOfWORDForDelete, count)
+    | #"$" => NormalYank.yankWhenMovingForward (app, Cursor.viDlr, 1)
     | #"^" =>
         let
           open DrawMsg
@@ -283,19 +264,36 @@ struct
           val {buffer, cursorIdx, ...} = app
 
           val buffer = LineGap.goToIdx (cursorIdx, buffer)
-          val low = Cursor.vi0 (buffer, cursorIdx)
+          val otherIdx = Cursor.vi0 (buffer, cursorIdx)
 
-          val buffer = LineGap.goToIdx (low, buffer)
-          val high = Cursor.firstNonSpaceChr (buffer, low)
-
-          val buffer = LineGap.goToIdx (high, buffer)
-          val length = high - low
-          val str = LineGap.substring (low, length, buffer)
-
-          val msg = YANK str
-          val mode = NORMAL_MODE ""
+          val buffer = LineGap.goToIdx (otherIdx, buffer)
+          val otherIdx = Cursor.firstNonSpaceChr (buffer, otherIdx)
         in
-          NormalModeWith.modeAndBuffer (app, buffer, mode, [DRAW msg])
+          if cursorIdx > otherIdx then
+            (* yanking backwards from cursorIdx *)
+            let
+              val () = print "272\n"
+              val length = cursorIdx - otherIdx + 1
+              val buffer = LineGap.goToIdx (otherIdx, buffer)
+
+              val str = LineGap.substring (otherIdx, length, buffer)
+              val msg = YANK str
+              val mode = NORMAL_MODE ""
+            in
+              NormalModeWith.modeAndBuffer (app, buffer, mode, [DRAW msg])
+            end
+          else if cursorIdx < otherIdx then
+            (* yanking forward from cursorIdx *)
+            let
+              val length = otherIdx - cursorIdx
+              val str = LineGap.substring (cursorIdx, length, buffer)
+              val msg = YANK str
+              val mode = NORMAL_MODE ""
+            in
+              NormalModeWith.modeAndBuffer (app, buffer, mode, [DRAW msg])
+            end
+          else
+            NormalFinish.clearMode app
         end
     | #"G" =>
         let
diff --git a/fcore/normal-mode/normal-yank.sml b/fcore/normal-mode/normal-yank.sml
new file mode 100644
index 0000000..3b3b65e
--- /dev/null
+++ b/fcore/normal-mode/normal-yank.sml
@@ -0,0 +1,87 @@
+structure NormalYank =
+struct
+  open AppType
+  open DrawMsg
+  open MailboxType
+
+  fun yankLine (app: app_type, count) =
+    let
+      open DrawMsg
+      open MailboxType
+
+      val {buffer, cursorIdx, ...} = app
+
+      val buffer = LineGap.goToIdx (cursorIdx, buffer)
+      val low = Cursor.vi0 (buffer, cursorIdx)
+
+      val buffer = LineGap.goToIdx (low, buffer)
+      val high = Cursor.viDlrForDelete (buffer, low, count)
+
+      val buffer = LineGap.goToIdx (high, buffer)
+      val length = high - low
+      val str = LineGap.substring (low, length, buffer)
+
+      val msg = YANK str
+      val mode = NORMAL_MODE ""
+    in
+      NormalModeWith.modeAndBuffer (app, buffer, mode, [DRAW msg])
+    end
+
+  fun yankToStartOfLine (app: app_type) =
+    let
+      open DrawMsg
+      open MailboxType
+
+      val {buffer, cursorIdx, ...} = app
+
+      val buffer = LineGap.goToIdx (cursorIdx, buffer)
+      val low = Cursor.vi0 (buffer, cursorIdx)
+
+      val length = cursorIdx - low
+      val str = LineGap.substring (low, length, buffer)
+
+      val msg = YANK str
+      val mode = NORMAL_MODE ""
+    in
+      NormalModeWith.modeAndBuffer (app, buffer, mode, [DRAW msg])
+    end
+
+  fun yankWhenMovingBack (app: app_type, fMove, count) =
+    let
+      open DrawMsg
+      open MailboxType
+
+      val {buffer, cursorIdx, ...} = app
+
+      val buffer = LineGap.goToIdx (cursorIdx, buffer)
+      val low = fMove (buffer, cursorIdx, count)
+
+      val length = cursorIdx - low
+      val str = LineGap.substring (low, length, buffer)
+
+      val msg = YANK str
+      val mode = NORMAL_MODE ""
+    in
+      NormalModeWith.modeAndBuffer (app, buffer, mode, [DRAW msg])
+    end
+
+  fun yankWhenMovingForward (app: app_type, fMove, count) =
+    let
+      open DrawMsg
+      open MailboxType
+
+      val {buffer, cursorIdx, ...} = app
+
+      val buffer = LineGap.goToIdx (cursorIdx, buffer)
+      val high = fMove (buffer, cursorIdx, count)
+
+      val buffer = LineGap.goToIdx (high, buffer)
+      val length = high - cursorIdx
+      val str = LineGap.substring (cursorIdx, length, buffer)
+
+      val msg = YANK str
+      val mode = NORMAL_MODE ""
+    in
+      NormalModeWith.modeAndBuffer (app, buffer, mode, [DRAW msg])
+    end
+end
diff --git a/shf.mlb b/shf.mlb
index 7c5e51a..52d7419 100644
--- a/shf.mlb
+++ b/shf.mlb
@@ -45,6 +45,7 @@ fcore/normal-mode/normal-search-finish.sml
 fcore/move.sml
 
 fcore/normal-mode/normal-move.sml
+fcore/normal-mode/normal-yank.sml
 fcore/normal-mode/normal-delete.sml
 fcore/normal-mode/normal-mode.sml
 fcore/normal-mode/normal-search-mode.sml