progress parsing normal mode commands

fcore/app-update.sml

@@ -19,49 +19,69 @@ struct
       (newApp, drawMsg)
     end
 
-  fun moveBackward (app: app_type, fMove) =
-    let
-      val {buffer, windowWidth, windowHeight, startLine, cursorIdx, ...} = app
+  fun helpMoveBackward (app: app_type, buffer, cursorIdx, count, fMove) =
+    if count = 0 then
+      let
+        val {windowWidth, windowHeight, startLine, ...} = app
+        (* todo: get new startLine if cursor has moved out of screen *)
 
+        (* move LineGap to first line displayed on screen, and build new text *)
+        val buffer = LineGap.goToLine (startLine, buffer)
+        val drawMsg = TextBuilder.build
+          (startLine, cursorIdx, buffer, windowWidth, windowHeight)
+
+        val mode = NORMAL_MODE ""
+        val newApp = AppWith.bufferAndCursorIdx (app, buffer, cursorIdx, mode)
+      in
+        (newApp, drawMsg)
+      end
+    else
       (* move LineGap to cursorIdx, which is necessary for finding newCursorIdx *)
-      val buffer = LineGap.goToIdx (cursorIdx, buffer)
-      val cursorIdx = fMove (buffer, cursorIdx)
+      let
+        val buffer = LineGap.goToIdx (cursorIdx, buffer)
+        val cursorIdx = fMove (buffer, cursorIdx)
+      in
+        helpMoveBackward (app, buffer, cursorIdx, count - 1, fMove)
+      end
 
-      (* todo: get new startLine if cursor has moved out of screen *)
-
-      (* move LineGap to first line displayed on screen, and build new text *)
-      val buffer = LineGap.goToLine (startLine, buffer)
-      val drawMsg = TextBuilder.build
-        (startLine, cursorIdx, buffer, windowWidth, windowHeight)
-
-      val newApp = AppWith.bufferAndCursorIdx (app, buffer, cursorIdx)
-    in
-      (newApp, drawMsg)
+  fun moveBackward (app: app_type, count, fMove) =
+    let val {cursorIdx, buffer, ...} = app
+    in helpMoveBackward (app, buffer, cursorIdx, count, fMove)
     end
 
-  fun moveFowrards (app: app_type, fMove) =
-    let
-      val {buffer, windowWidth, windowHeight, startLine, cursorIdx, ...} = app
+  fun helpMoveForwards (app: app_type, buffer, cursorIdx, count, fMove) =
+    if count = 0 then
+      let
+        val {windowWidth, windowHeight, startLine, ...} = app
+        (* todo: get new startLine if cursor has moved out of screen *)
 
-      (* move LineGap to cursorIdx, which is necessary for finding newCursorIdx *)
-      val buffer = LineGap.goToIdx (cursorIdx, buffer)
-      val cursorIdx = fMove (buffer, cursorIdx)
+        (* move LineGap to first line displayed on screen, and build new text *)
+        val buffer = LineGap.goToLine (startLine, buffer)
+        val drawMsg = TextBuilder.build
+          (startLine, cursorIdx, buffer, windowWidth, windowHeight)
 
-      (* todo: get new startLine if cursor has moved out of screen *)
+        val mode = NORMAL_MODE ""
+        val newApp = AppWith.bufferAndCursorIdx (app, buffer, cursorIdx, mode)
+      in
+        (newApp, drawMsg)
+      end
+    else
+      let
+        (* move LineGap to cursorIdx, which is necessary for finding newCursorIdx *)
+        val buffer = LineGap.goToIdx (cursorIdx, buffer)
+        val cursorIdx = fMove (buffer, cursorIdx)
+      in
+        helpMoveForwards (app, buffer, cursorIdx, count - 1, fMove)
+      end
 
-      (* move LineGap to first line displayed on screen, and build new text *)
-      val buffer = LineGap.goToLine (startLine, buffer)
-      val drawMsg = TextBuilder.build
-        (startLine, cursorIdx, buffer, windowWidth, windowHeight)
-
-      val newApp = AppWith.bufferAndCursorIdx (app, buffer, cursorIdx)
-    in
-      (newApp, drawMsg)
+  fun moveForwards (app: app_type, count, fMove) =
+    let val {cursorIdx, buffer, ...} = app
+    in helpMoveForwards (app, buffer, cursorIdx, count, fMove)
     end
 
   fun firstNonSpaceChr (app: app_type) =
     let
-      val {buffer, windowWidth, windowHeight, startLine, cursorIdx, ...} = app
+      val {buffer, cursorIdx, windowWidth, windowHeight, startLine, ...} = app
 
       (* move LineGap and buffer to start of line *)
       val buffer = LineGap.goToIdx (cursorIdx, buffer)
@@ -78,30 +98,79 @@ struct
       val drawMsg = TextBuilder.build
         (startLine, cursorIdx, buffer, windowWidth, windowHeight)
 
-      val newApp = AppWith.bufferAndCursorIdx (app, buffer, cursorIdx)
+      val mode = NORMAL_MODE ""
+      val newApp = AppWith.bufferAndCursorIdx (app, buffer, cursorIdx, mode)
     in
       (newApp, drawMsg)
     end
 
-  fun handleChr (app: app_type, chr) =
+  (* number of characters which are integers *)
+  fun getNumLength (pos, str) =
+    if pos = String.size str then
+      pos
+    else
+      let
+        val chr = String.sub (str, pos)
+      in
+        if chr >= #"0" andalso chr <= #"9" then getNumLength (pos + 1, str)
+        else pos
+      end
+
+  fun handleChr (app: app_type, count, chr, str) =
     case chr of
-      #"h" => moveBackward (app, Cursor.viH) 
-    | #"j" => moveFowrards (app, Cursor.viJ)
-    | #"k" => moveBackward (app, Cursor.viK)
-    | #"l" => moveFowrards (app, Cursor.viL)
-    | #"0" => moveBackward (app, Cursor.vi0)
-    | #"$" => moveFowrards (app, Cursor.viDlr)
-    | #"w" => moveFowrards (app, Cursor.nextWord)
-    | #"W" => moveFowrards (app, Cursor.nextWORD)
-    | #"b" => moveBackward (app, Cursor.prevWord)
-    | #"B" => moveBackward (app, Cursor.prevWORD)
-    | #"e" => moveFowrards (app, Cursor.endOfWord)
-    | #"E" => moveFowrards (app, Cursor.endOfWORD)
+      #"h" => moveBackward (app, count, Cursor.viH)
+    | #"j" => moveForwards (app, count, Cursor.viJ)
+    | #"k" => moveBackward (app, count, Cursor.viK)
+    | #"l" => moveForwards (app, count, Cursor.viL)
+    | #"0" => moveBackward (app, 1, Cursor.vi0)
+    | #"$" => moveForwards (app, 1, Cursor.viDlr)
+    | #"w" => moveForwards (app, count, Cursor.nextWord)
+    | #"W" => moveForwards (app, count, Cursor.nextWORD)
+    | #"b" => moveBackward (app, count, Cursor.prevWord)
+    | #"B" => moveBackward (app, count, Cursor.prevWORD)
+    | #"e" => moveForwards (app, count, Cursor.endOfWord)
+    | #"E" => moveForwards (app, count, Cursor.endOfWORD)
     | #"^" => firstNonSpaceChr app
-    | _ => (app, [])
+    | _ =>
+        (* user may be entering a cmd with more than one chr
+         * such as "2dw" to delete two word
+         * so add current chr to mode, and save it in the app state *)
+        let
+          val str =
+            if chr >= #"0" andalso chr <= #"9" then str ^ Char.toString chr
+            else ""
+          val mode = NORMAL_MODE str
+          val newApp = AppWith.mode (app, mode)
+        in
+          (newApp, [])
+        end
+
+  fun parseNormalModeCommand (app, str, newCmd) =
+    if String.size str = 0 then
+      case newCmd of
+        RESIZE_EVENT (width, height) => resizeText (app, width, height)
+      | CHAR_EVENT chr => handleChr (app, 1, chr, str)
+    else
+      let
+        val numLength = getNumLength (0, str)
+        val count = String.substring (str, 0, numLength)
+        val count =
+          case Int.fromString count of
+            SOME x => x
+          | NONE => 1
+      in
+        if numLength = String.size str then
+          (* reached end of str; str only contained numbers *)
+          case newCmd of
+            RESIZE_EVENT (width, height) => resizeText (app, width, height)
+          | CHAR_EVENT chr => handleChr (app, count, chr, str)
+        else
+          (* todo: continue parsing. *)
+          raise Match
+      end
+
+  fun updateNormalMode (app, str, msg) = parseNormalModeCommand (app, str, msg)
 
   fun update (app, msg) =
-    case msg of
-      RESIZE_EVENT (width, height) => resizeText (app, width, height)
-    | CHAR_EVENT chr => handleChr (app, chr)
+    case #mode app of NORMAL_MODE str => updateNormalMode (app, str, msg)
 end

fcore/app-with.sml

@@ -22,13 +22,18 @@ struct
       }
     end
 
-  fun bufferAndCursorIdx (app: app_type, newBuffer, newCursorIdx) =
+  fun bufferAndCursorIdx (app: app_type, newBuffer, newCursorIdx, newMode) =
     let
       val
-        {mode, buffer = _, cursorIdx = _, windowWidth, windowHeight, startLine} =
-        app
+        { mode = _
+        , buffer = _
+        , cursorIdx = _
+        , windowWidth
+        , windowHeight
+        , startLine
+        } = app
     in
-      { mode = mode
+      { mode = newMode
       , buffer = newBuffer
       , cursorIdx = newCursorIdx
       , windowWidth = windowWidth
@@ -36,4 +41,18 @@ struct
       , startLine = startLine
       }
     end
+
+  fun mode (app: app_type, newMode) =
+    let
+      val {mode = _, buffer, cursorIdx, windowWidth, windowHeight, startLine} =
+        app
+    in
+      { mode = newMode
+      , buffer = buffer
+      , cursorIdx = cursorIdx
+      , windowWidth = windowWidth
+      , windowHeight = windowHeight
+      , startLine = startLine
+      }
+    end
 end