simplify and rewrite function 'del' in search-list.sml

fcore/app-update.sml

@@ -363,9 +363,34 @@ struct
 
   (* text-delete functions *)
   (** equivalent of vi's 'x' command **)
-  fun helpRemoveChr (app: app_type, buffer, cursorIdx, count) =
+  fun helpRemoveChr (app: app_type, buffer, searchList, cursorIdx, count) =
     if count = 0 then
-      buildTextAndClear (app, buffer, cursorIdx)
+      let
+        val {windowWidth, windowHeight, startLine, searchString, ...} =
+          app
+
+        (* move LineGap to first line displayed on screen *)
+        val buffer = LineGap.goToLine (startLine, buffer)
+
+        (* get new startLine which may move screen depending on cursor movements *)
+        val startLine = TextWindow.getStartLine
+          (buffer, startLine, cursorIdx, windowWidth, windowHeight)
+
+        (* move buffer to new startLine as required by TextBuilder.build *)
+        val buffer = LineGap.goToLine (startLine, buffer)
+
+        val drawMsg = TextBuilder.build
+          ( startLine, cursorIdx, buffer
+          , windowWidth, windowHeight
+          , searchList, searchString
+          )
+
+        val mode = NORMAL_MODE ""
+        val newApp = AppWith.onDelete
+          (app, buffer, cursorIdx, mode, startLine, searchList)
+      in
+        (newApp, drawMsg)
+      end
     else
       let
         val buffer = LineGap.goToIdx (cursorIdx, buffer)
@@ -388,14 +413,17 @@ struct
           (* vi simply doesn't do anything on 'x' command
            * when cursor is at start of line, and next chr is line break 
            * so skip to end of loop by passing count of 0 *)
-          helpRemoveChr (app, buffer, cursorIdx, 0)
+          helpRemoveChr (app, buffer, searchList, cursorIdx, 0)
         else if cursorIsStart then
-          helpRemoveChr (app, buffer, cursorIdx, 0)
+          helpRemoveChr (app, buffer, searchList, cursorIdx, 0)
         else if nextIsEnd then
           let
             (* delete char at cursor and then decrement cursorIdx by 1
              * if cursorIdx is not 0 *)
             val buffer = LineGap.delete (cursorIdx, 1, buffer)
+            val searchList = SearchList.delete (cursorIdx, 1, searchList)
+            val searchList = SearchList.mapFrom (cursorIdx, ~1, searchList)
+
             val cursorIdx =
               if
                 Cursor.isPrevChrStartOfLine (buffer, cursorIdx)
@@ -403,16 +431,20 @@ struct
               then cursorIdx
               else cursorIdx - 1
           in
-            helpRemoveChr (app, buffer, cursorIdx, count - 1)
+            helpRemoveChr (app, buffer, searchList, cursorIdx, count - 1)
           end
         else
-          let val buffer = LineGap.delete (cursorIdx, 1, buffer)
-          in helpRemoveChr (app, buffer, cursorIdx, count - 1)
+          let 
+            val buffer = LineGap.delete (cursorIdx, 1, buffer)
+            val searchList = SearchList.delete (cursorIdx, 1, searchList)
+            val searchList = SearchList.mapFrom (cursorIdx, ~1, searchList)
+          in 
+            helpRemoveChr (app, buffer, searchList, cursorIdx, count - 1)
           end
       end
 
   fun removeChr (app: app_type, count) =
-    helpRemoveChr (app, #buffer app, #cursorIdx app, count)
+    helpRemoveChr (app, #buffer app, #searchList app, #cursorIdx app, count)
 
   fun helpDelete (app: app_type, buffer, cursorIdx, otherIdx, count, fMove) =
     (* As a small optimisation to reduce allocations, 
@@ -470,8 +502,10 @@ struct
           val lastChr = Cursor.viDlr (buffer, cursorIdx)
           val length = lastChr - cursorIdx
           val buffer = LineGap.delete (cursorIdx, length, buffer)
+
+          (* todo: delete from searchList and map *)
         in
-          helpRemoveChr (app, buffer, cursorIdx, 1)
+          helpRemoveChr (app, buffer, #searchList app, cursorIdx, 1)
         end
     end
 

fcore/app-with.sml

@@ -75,6 +75,31 @@ struct
       }
     end
 
+  fun onDelete
+    (app: app_type, newBuffer, newCursorIdx, newMode, newStartLine, newSearchList) =
+    let
+      val
+        { mode = _
+        , buffer = _
+        , cursorIdx = _
+        , startLine = _
+        , searchList = _
+        , searchString
+        , windowWidth
+        , windowHeight
+        } = app
+    in
+      { mode = newMode
+      , buffer = newBuffer
+      , cursorIdx = newCursorIdx
+      , startLine = newStartLine
+      , searchList = newSearchList
+      , searchString = searchString
+      , windowWidth = windowWidth
+      , windowHeight = windowHeight
+      }
+    end
+
   fun mode (app: app_type, newMode) =
     let
       val

fcore/search-list.sml

@@ -8,13 +8,26 @@ sig
   val delete: int * int * t -> t
 
   val goToNum: int * t -> t
-  val mapFromNum: int * int * t -> t
+  val mapFrom: int * int * t -> t
 end
 
 structure SearchList :> SEARCH_LIST =
 struct
   type t = {left: int vector list, right: int vector list}
 
+  (* temp function for testing *)
+  fun printlst (left, right) =
+    let
+      val left = List.rev left
+      val lst = List.concat [left, right]
+      val v = Vector.concat lst
+      val _ = print "\nstart print list:\n"
+      val _ = Vector.map (fn el => print (" " ^ Int.toString el ^ ",")) v
+      val _ = print "\nend print list\n"
+    in
+      ()
+    end
+
   val targetLength = 1024
 
   val empty: t = {left = [], right = []}
@@ -379,54 +392,25 @@ struct
           val rfirst = Vector.sub (rhd, 0)
         in
           if start < rfirst then
-            (case left of
-               lhd :: ltl =>
-                 let
-                   val llast = Vector.sub (lhd, Vector.length lhd - 1)
-                 in
-                   if
-                     start < llast
-                   then
-                     if finish < rfirst then
-                       (* start < rfirst and start < llast and finish < rfirst
-                        * move left and delete *)
-                       moveLeftAndDelete (start, finish, left, right)
-                     else
-                       (* start < rfirst and start < llast and finish >= rfirst
-                        * in middle; delete from both sides *)
-                       delFromLeftAndRight (start, finish, left, right)
-                   else if
-                     start = llast
-                   then
-                     if finish < rfirst then
-                       (* start < rfirst, start = llast, and finish < rfirst
-                        * so just have to delete left from here *)
-                       delLeftFromHere (start, left, right)
-                     else
-                       (* start < rfirst, start = llast, finish >= rfirst
-                        * in middle; delete from both sides *)
-                       delFromLeftAndRight (start, finish, left, right)
-                   else (* start > llast and start < rfirst *) if
-                     finish >= rfirst
-                   then
-                     (* delete right from here *)
-                     delRightFromHere (finish, left, right)
-                   else
-                     (* start < rfirst and finish < rfirst
-                      * so just return *)
-                     {left = left, right = right}
-                 end
-             | [] =>
-                 (* start < rfirst 
-                  * but left is empty.
-                  * All we can do is 1. Delete right or 2. Return *)
-                 if finish < rfirst then {left = left, right = right}
-                 else delRightFromHere (finish, left, right))
+            if finish < rfirst then
+              (case left of
+                lhd :: ltl =>
+                  let
+                    val llast = Vector.sub (lhd, Vector.length lhd - 1)
+                  in
+                    if finish = llast then
+                      delLeftFromHere (start, left, right)
+                    else
+                      moveLeftAndDelete (start, finish, left, right)
+                  end
+              | [] =>
+                  {left = left, right = right})
+            else
+              (* finish >= rfirst *)
+              delFromLeftAndRight (start, finish, left, right)
           else if start = rfirst then
             delRightFromHere (finish, left, right)
-          else
-            (* start > rfirst 
-             * move right and then start deleting *)
+          else 
             moveRightAndDelete (start, finish, left, right)
         end
     | [] =>
@@ -435,13 +419,11 @@ struct
              let
                val llast = Vector.sub (lhd, Vector.length lhd - 1)
              in
-               if start < llast then
-                 if finish <= llast then
-                   moveRightAndDelete (start, finish, left, right)
-                 else
-                   delLeftFromHere (finish, left, right)
+               if finish >= llast then
+                 delLeftFromHere (start, left, right)
                else
-                 moveRightAndDelete (start, finish, left, right)
+                 (* finish < last *)
+                 moveLeftAndDelete (start, finish, left, right)
              end
          | [] =>
              (* left and right are both empty *)
@@ -493,7 +475,7 @@ struct
         end
     | [] => {left = left, right = right}
 
-  fun mapFromNum (num, mapBy, lst) =
+  fun mapFrom (num, mapBy, lst) =
     let
       (* goToNum always places vector where num was found to the right list *)
       val {left, right} = goToNum (num, lst)