From 204f549c79fb1e4e993f300816e7a68077193786 Mon Sep 17 00:00:00 2001
From: Humza Shahid <humzasaur@gmail.com>
Date: Sat, 13 Dec 2025 03:40:32 +0000
Subject: [PATCH] implement 'daw' motion

---
 fcore/cursor.sml                         | 172 ++++++++++++++++++++++-
 fcore/normal-mode/make-normal-delete.sml |  31 ++++
 fcore/normal-mode/normal-mode.sml        |   4 +-
 temp.txt                                 |   3 +
 4 files changed, 208 insertions(+), 2 deletions(-)

diff --git a/fcore/cursor.sml b/fcore/cursor.sml
index ce20cc4..fd1344b 100644
--- a/fcore/cursor.sml
+++ b/fcore/cursor.sml
@@ -619,7 +619,177 @@ struct
   fun lastContiguousNonSpace (lineGap, cursorIdx) =
     LastContiguousNonSpace.foldNext (lineGap, cursorIdx, ())
 
-  (* Prerequisite: lineGap is moved to cursorIdx *)
+  structure AroundWordPrev =
+    MakeIfCharFolderPrev
+      (struct
+         type env = unit
+
+         fun loopAlphaNum (strPos, shd, absIdx, stl) =
+           if strPos < 0 then
+             case stl of
+               shd :: stl =>
+                 loopAlphaNum (String.size shd - 1, shd, absIdx, stl)
+             | [] => 0
+           else
+             let
+               val chr = String.sub (shd, strPos)
+             in
+               if Char.isAlphaNum chr orelse chr = #"_" then
+                 loopAlphaNum (strPos - 1, shd, absIdx - 1, stl)
+               else
+                 absIdx + 1
+             end
+
+         fun loopPunct (strPos, shd, absIdx, stl) =
+           if strPos < 0 then
+             case stl of
+               shd :: stl => loopPunct (String.size shd - 1, shd, absIdx, stl)
+             | [] => 0
+           else
+             let
+               val chr = String.sub (shd, strPos)
+             in
+               if
+                 Char.isAlphaNum chr orelse chr = #"_" orelse chr = #"\n"
+                 orelse Char.isSpace chr
+               then absIdx + 1
+               else (* is punct *) loopPunct (strPos - 1, shd, absIdx - 1, stl)
+             end
+
+         fun loopSpace (strPos, shd, absIdx, stl) =
+           if strPos < 0 then
+             case stl of
+               shd :: stl => loopSpace (String.size shd - 1, shd, absIdx, stl)
+             | [] => 0
+           else
+             let
+               val chr = String.sub (shd, strPos)
+             in
+               if chr = #"\n" then
+                 absIdx + 1
+               else if Char.isSpace chr then
+                 loopSpace (strPos - 1, shd, absIdx - 1, stl)
+               else
+                 absIdx + 1
+             end
+
+         fun fStart (strPos, shd, _, absIdx, stl, _, _) =
+           let
+             val chr = String.sub (shd, strPos)
+           in
+             if chr = #"\n" then
+               absIdx
+             else if Char.isAlphaNum chr orelse chr = #"_" then
+               loopAlphaNum (strPos - 1, shd, absIdx - 1, stl)
+             else if Char.isSpace chr then
+               loopSpace (strPos - 1, shd, absIdx - 1, stl)
+             else
+               loopPunct (strPos - 1, shd, absIdx - 1, stl)
+           end
+       end)
+
+  fun aroundWordPrev (lineGap, cursorIdx) =
+    AroundWordPrev.foldPrev (lineGap, cursorIdx, ())
+
+  structure AroundWordNext =
+    MakeIfCharFolderNext
+      (struct
+         type env = unit
+
+         fun stopAtFirstNonSpace (strPos, shd, absIdx, stl) =
+           if strPos = String.size shd then
+             case stl of
+               shd :: stl => stopAtFirstNonSpace (0, shd, absIdx, stl)
+             | [] => absIdx
+           else
+             let
+               val chr = String.sub (shd, strPos)
+             in
+               if chr = #"\n" then
+                 absIdx - 1
+               else if Char.isSpace chr then
+                 stopAtFirstNonSpace (strPos + 1, shd, absIdx + 1, stl)
+               else
+                 absIdx - 1
+             end
+
+         fun loopAlphaNum (strPos, shd, absIdx, stl) =
+           if strPos = String.size shd then
+             case stl of
+               shd :: stl => loopAlphaNum (0, shd, absIdx, stl)
+             | [] => absIdx
+           else
+             let
+               val chr = String.sub (shd, strPos)
+             in
+               if chr = #"\n" then
+                 absIdx - 1
+               else if Char.isAlphaNum chr orelse chr = #"_" then
+                 loopAlphaNum (strPos + 1, shd, absIdx + 1, stl)
+               else if Char.isSpace chr then
+                 stopAtFirstNonSpace (strPos + 1, shd, absIdx + 1, stl)
+               else
+                 (* is punct *)
+                 absIdx - 1
+             end
+
+         fun loopPunct (strPos, shd, absIdx, stl) =
+           if strPos = String.size shd then
+             case stl of
+               shd :: stl => loopPunct (0, shd, absIdx, stl)
+             | [] => absIdx
+           else
+             let
+               val chr = String.sub (shd, strPos)
+             in
+               if chr = #"\n" then
+                 absIdx - 1
+               else if Char.isAlphaNum chr orelse chr = #"_" then
+                 absIdx - 1
+               else if Char.isSpace chr then
+                 stopAtFirstNonSpace (strPos + 1, shd, absIdx + 1, stl)
+               else
+                 (* is punct *)
+                 loopPunct (strPos + 1, shd, absIdx + 1, stl)
+             end
+
+         fun loopSpace (strPos, shd, absIdx, stl) =
+           if strPos = String.size shd then
+             case stl of
+               shd :: stl => loopSpace (0, shd, absIdx, stl)
+             | [] => absIdx
+           else
+             let
+               val chr = String.sub (shd, strPos)
+             in
+               if chr = #"\n" then
+                 absIdx - 1
+               else if Char.isAlphaNum chr orelse chr = #"_" then
+                 loopAlphaNum (strPos + 1, shd, absIdx + 1, stl)
+               else if Char.isSpace chr then
+                 loopSpace (strPos + 1, shd, absIdx + 1, stl)
+               else
+                 loopPunct (strPos + 1, shd, absIdx + 1, stl)
+             end
+
+         fun fStart (strPos, shd, _, absIdx, stl, _, _) =
+           let
+             val chr = String.sub (shd, strPos)
+           in
+             if chr = #"\n" then
+               absIdx
+             else if Char.isAlphaNum chr orelse chr = #"_" then
+               loopAlphaNum (strPos + 1, shd, absIdx + 1, stl)
+             else if Char.isSpace chr then
+               loopSpace (strPos + 1, shd, absIdx + 1, stl)
+             else
+               loopPunct (strPos + 1, shd, absIdx + 1, stl)
+           end
+       end)
+
+  fun aroundWordNext (lineGap, cursorIdx) =
+    AroundWordNext.foldNext (lineGap, cursorIdx, ())
+
   fun isCursorAtStartOfLine (lineGap: LineGap.t, cursorIdx) =
     let
       val {rightStrings, idx = bufferIdx, ...} = lineGap
diff --git a/fcore/normal-mode/make-normal-delete.sml b/fcore/normal-mode/make-normal-delete.sml
index 2b8cfc0..9882358 100644
--- a/fcore/normal-mode/make-normal-delete.sml
+++ b/fcore/normal-mode/make-normal-delete.sml
@@ -23,7 +23,14 @@ struct
       val initialMsg = Fn.initMsgs (low, length, buffer)
       val buffer = LineGap.delete (low, length, buffer)
 
+      val low =
+        if low >= #textLength buffer - 1 then
+          Int.max (#textLength buffer - 1, 0)
+        else
+          low
+
       val buffer = LineGap.goToIdx (low, buffer)
+
       val low =
         if Cursor.isOnNewlineAfterChr (buffer, low) then low - 1 else low
     in
@@ -973,6 +980,30 @@ struct
         end
     end
 
+  fun deleteAroundWord (app: app_type, time) =
+    let
+      val {buffer, cursorIdx, dfa, ...} = app
+      val buffer = LineGap.goToIdx (cursorIdx, buffer)
+
+      val low = Cursor.aroundWordPrev (buffer, cursorIdx)
+      val high = Cursor.aroundWordNext (buffer, cursorIdx) + 1
+
+      val length = high - low
+    in
+      deleteAndFinish (app, low, length, buffer, time)
+    end
+
+  fun deleteAroundWORD (app: app_type, time) =
+    let
+      val {buffer, cursorIdx, dfa, ...} = app
+      val buffer = LineGap.goToIdx (cursorIdx, buffer)
+      val low = raise Fail "unimplemented"
+      val high = raise Fail "unimplemented"
+      val length = high - low
+    in
+      deleteAndFinish (app, low, length, buffer, time)
+    end
+
   fun finishAfterDeleteInside (app: app_type, origLow, high, time) =
     if origLow = high then
       NormalFinish.clearMode app
diff --git a/fcore/normal-mode/normal-mode.sml b/fcore/normal-mode/normal-mode.sml
index e3e3863..7106b9f 100644
--- a/fcore/normal-mode/normal-mode.sml
+++ b/fcore/normal-mode/normal-mode.sml
@@ -234,7 +234,9 @@ struct
 
     fun parseDeleteAround (app, chr, time) =
       case chr of
-        #"(" => NormalDelete.deleteAroundChrOpen (app, chr, time)
+        #"w" => NormalDelete.deleteAroundWord (app, time)
+      | #"W" => NormalDelete.deleteAroundWORD (app, time)
+      | #"(" => NormalDelete.deleteAroundChrOpen (app, chr, time)
       | #"[" => NormalDelete.deleteAroundChrOpen (app, chr, time)
       | #"{" => NormalDelete.deleteAroundChrOpen (app, chr, time)
       | #"<" => NormalDelete.deleteAroundChrOpen (app, chr, time)
diff --git a/temp.txt b/temp.txt
index 9b48555..0424254 100644
--- a/temp.txt
+++ b/temp.txt
@@ -1 +1,4 @@
 hello abc_123 world
+
+fun hello () =
+  print (##)lo"