add functionality for commands: 'dgg' (delete from cursor to start of buffer), 'dge' (delete from cursor to the end of the previous word) and 'dgE' (delete from cursor to the end of the previous WORD)

fcore/app-update.sml

@@ -463,6 +463,26 @@ struct
     helpDeleteToChr 
       (app, #buffer app, #cursorIdx app, #cursorIdx app, count, fMove, fInc, chr)
 
+  fun deleteToStart (app: app_type) =
+    let
+      val {cursorIdx, buffer, windowWidth, windowHeight, ...} = app
+
+      val buffer = LineGap.delete(0, cursorIdx, buffer)
+      val cursorIdx = 0
+      val startLine = 0
+      val buffer = LineGap.goToIdx (cursorIdx, buffer)
+
+      val drawMsg = 
+        TextBuilder.build
+          (startLine, cursorIdx, buffer, windowWidth, windowHeight)
+
+      val mode = NORMAL_MODE ""
+      val newApp = AppWith.bufferAndCursorIdx
+        (app, buffer, cursorIdx, mode, startLine)
+    in
+      (newApp, drawMsg)
+    end
+
   (* command-parsing functions *)
   (** number of characters which are integers *)
   fun getNumLength (pos, str) =
@@ -592,44 +612,40 @@ struct
         #"t" => 
           (* delete till chr, forwards *)
           (case newCmd of
-            CHAR_EVENT chr =>
-              deleteToChr (app, 1, Cursor.tillNextChr, op+, chr)
-          | KEY_ESC =>
-              clearMode app
-          | RESIZE_EVENT (width, height) => 
-              resizeText (app, width, height))
+            CHAR_EVENT chr => deleteToChr (app, 1, Cursor.tillNextChr, op+, chr)
+          | KEY_ESC => clearMode app
+          | RESIZE_EVENT (width, height) => resizeText (app, width, height))
       | #"T" => 
           (* delete till chr, backwards *)
           (case newCmd of
-            CHAR_EVENT chr =>
-              deleteToChr (app, 1, Cursor.tillPrevChr, op-, chr)
-          | KEY_ESC =>
-              clearMode app
-          | RESIZE_EVENT (width, height) => 
-              resizeText (app, width, height))
+            CHAR_EVENT chr => deleteToChr (app, 1, Cursor.tillPrevChr, op-, chr)
+          | KEY_ESC => clearMode app
+          | RESIZE_EVENT (width, height) => resizeText (app, width, height))
       | #"d" => 
           (* delete whole line *)
           clearMode app
       | #"f" => 
           (case newCmd of
-            CHAR_EVENT chr =>
-              deleteToChr (app, count, Cursor.toNextChr, op+, chr)
-          | KEY_ESC =>
-              clearMode app
-          | RESIZE_EVENT (width, height) => 
-              resizeText (app, width, height))
+            CHAR_EVENT chr => deleteToChr (app, count, Cursor.toNextChr, op+, chr)
+          | KEY_ESC => clearMode app
+          | RESIZE_EVENT (width, height) => resizeText (app, width, height))
       | #"F" => 
           (* delete to chr, backwards *)
           (case newCmd of
-            CHAR_EVENT chr =>
-              deleteToChr (app, count, Cursor.toPrevChr, op-, chr)
-          | KEY_ESC =>
-              clearMode app
-          | RESIZE_EVENT (width, height) => 
-              resizeText (app, width, height))
+            CHAR_EVENT chr => deleteToChr (app, count, Cursor.toPrevChr, op-, chr)
+          | KEY_ESC => clearMode app
+          | RESIZE_EVENT (width, height) => resizeText (app, width, height))
       | #"g" => 
-          (* todo: same events as handleGo *)
-          clearMode app
+          (* same events as handleGo *)
+          (case newCmd of
+            CHAR_EVENT chr =>
+              (case chr of
+                 #"e" => delete (app, count, Cursor.endOfPrevWord)
+               | #"E" => delete (app, count, Cursor.endOfPrevWORD)
+               | #"g" => deleteToStart app
+               | _ => clearMode app)
+          | KEY_ESC => clearMode app
+          | RESIZE_EVENT (width, height) => resizeText (app, width, height))
       | _ => clearMode app
 
   (* useful reference as list of non-terminal commands *)