address todo in text-builder.sml by adding prerequisite: always call SearchList.goToNum before calling TextBuilder.build

fcore/app-update.sml

@@ -28,6 +28,9 @@ struct
         } = app
 
       val newBuffer = LineGap.goToLine (startLine, buffer)
+      val lineIdx = TextBuilder.getLineAbsIdx (startLine, buffer)
+      val searchList = SearchList.goToNum (lineIdx, searchList)
+
       val drawMsg = TextBuilder.build
         ( startLine
         , cursorIdx
@@ -38,7 +41,8 @@ struct
         , searchString
         )
 
-      val newApp = AppWith.bufferAndSize (app, newBuffer, newWidth, newHeight)
+      val newApp = 
+        AppWith.bufferAndSize (app, newBuffer, newWidth, newHeight, searchList)
     in
       (newApp, drawMsg)
     end
@@ -47,7 +51,8 @@ struct
     let
       val {windowWidth, windowHeight, startLine, searchString, ...} = app
 
-      (* move LineGap to first line displayed on screen *)
+      (* move LineGap to first line displayed on screen 
+       * and move searchList to line's start idx as well *)
       val buffer = LineGap.goToLine (startLine, buffer)
 
       (* get new startLine which may move screen depending on cursor movements *)
@@ -56,6 +61,8 @@ struct
 
       (* move buffer to new startLine as required by TextBuilder.build *)
       val buffer = LineGap.goToLine (startLine, buffer)
+      val lineIdx = TextBuilder.getLineAbsIdx (startLine, buffer)
+      val searchList = SearchList.goToNum (lineIdx, searchList)
 
       val drawMsg = TextBuilder.build
         ( startLine
@@ -90,8 +97,11 @@ struct
       val startLine = TextWindow.getStartLine
         (buffer, startLine, cursorIdx, windowWidth, windowHeight)
 
-      (* move buffer to new startLine as required by TextBuilder.build *)
+      (* move buffer to new startLine as required by TextBuilder.build 
+       * and move searchList to idx where line starts as well *)
       val buffer = LineGap.goToLine (startLine, buffer)
+      val lineIdx = TextBuilder.getLineAbsIdx (startLine, buffer)
+      val searchList = SearchList.goToNum (lineIdx, searchList)
 
       val drawMsg = TextBuilder.build
         ( startLine
@@ -128,6 +138,8 @@ struct
         (buffer, cursorIdx, origLine, windowWidth, windowHeight div 2)
 
       val buffer = LineGap.goToLine (startLine, buffer)
+      val lineIdx = TextBuilder.getLineAbsIdx (startLine, buffer)
+      val searchList = SearchList.goToNum (lineIdx, searchList)
 
       val newApp = AppWith.bufferAndCursorIdx
         (app, buffer, cursorIdx, NORMAL_MODE "", startLine, searchList)
@@ -155,6 +167,7 @@ struct
       val cursorIdx = 0
       val startLine = 0
       val buffer = LineGap.goToIdx (cursorIdx, buffer)
+      val searchList = SearchList.goToNum (0, searchList)
 
       val drawMsg = TextBuilder.build
         ( startLine
@@ -195,6 +208,9 @@ struct
         end
 
       val buffer = LineGap.goToLine (bufferLine, buffer)
+      val lineIdx = TextBuilder.getLineAbsIdx (bufferLine, buffer)
+      val searchList = SearchList.goToNum (lineIdx, searchList)
+
       val drawMsg = TextBuilder.build
         ( bufferLine
         , bufferIdx
@@ -236,6 +252,8 @@ struct
           (buffer, cursorIdx, origLine, windowWidth, windowHeight div 2)
 
         val buffer = LineGap.goToLine (startLine, buffer)
+        val lineIdx = TextBuilder.getLineAbsIdx (startLine, buffer)
+        val searchList = SearchList.goToNum (lineIdx, searchList)
 
         val newApp = AppWith.bufferAndCursorIdx
           (app, buffer, cursorIdx, NORMAL_MODE "", startLine, searchList)
@@ -297,6 +315,8 @@ struct
       val cursorIdx = Cursor.matchPair (buffer, cursorIdx)
 
       val buffer = LineGap.goToLine (startLine, buffer)
+      val lineIdx = TextBuilder.getLineAbsIdx (startLine, buffer)
+      val searchList = SearchList.goToNum (lineIdx, searchList)
     in
       if
         TextWindow.isCursorVisible
@@ -327,6 +347,8 @@ struct
             (buffer, cursorIdx, startLine, windowWidth, windowHeight div 2)
 
           val buffer = LineGap.goToLine (startLine, buffer)
+          val lineIdx = TextBuilder.getLineAbsIdx (startLine, buffer)
+          val searchList = SearchList.goToNum (lineIdx, searchList)
 
           val newApp = AppWith.bufferAndCursorIdx
             (app, buffer, cursorIdx, NORMAL_MODE "", startLine, searchList)
@@ -700,6 +722,7 @@ struct
       val cursorIdx = 0
       val startLine = 0
       val buffer = LineGap.goToIdx (cursorIdx, buffer)
+      val searchList = SearchList.goToNum (0, searchList)
 
       val drawMsg = TextBuilder.build
         ( startLine

fcore/app-with.sml

@@ -26,14 +26,15 @@ struct
       }
     end
 
-  fun bufferAndSize (app: app_type, newBuffer, newWidth, newHeight) =
+  fun bufferAndSize
+    (app: app_type, newBuffer, newWidth, newHeight, newSearchList) =
     let
       val
         { mode
         , buffer = _
         , windowWidth = _
         , windowHeight = _
-        , searchList
+        , searchList = _
         , searchString
         , startLine
         , cursorIdx
@@ -43,7 +44,7 @@ struct
       , buffer = newBuffer
       , windowWidth = newWidth
       , windowHeight = newHeight
-      , searchList = searchList
+      , searchList = newSearchList
       , searchString = searchString
       , startLine = startLine
       , cursorIdx = cursorIdx

fcore/text-builder.sml

@@ -1,5 +1,8 @@
 signature TEXT_BUILDER =
 sig
+  (* Prerequisites: LineGap is moved to requested line first. *)
+  val getLineAbsIdx: int * LineGap.t -> int
+
   (* Prerequisites: LineGap is moved to requested line first. *)
   val build: int * int * LineGap.t * int * int * SearchList.t * string
              -> MailboxType.t list
@@ -459,6 +462,45 @@ struct
          | [] =>
              accToDrawMsg (acc, cursorAcc, bgAcc)
 
+  (* gets line start idx, relative to right hd *)
+  fun helpGetLineStartIdx (startLine, curLine, rLnHd) =
+    if startLine > curLine then
+      let
+        val lnPos = startLine - curLine - 1
+      in
+        Vector.sub (rLnHd, lnPos) + 1
+      end
+    else
+      0
+
+  (* gets line start idx, absolute *)
+  fun helpGetLineAbsIdx (curIdx, startLine, curLine, rLnHd) =
+    let
+      val startIdx =
+        if startLine > curLine then
+          let
+            val lnPos = startLine - curLine - 1
+          in
+            Vector.sub (rLnHd, lnPos) + 1
+          end
+        else
+          0
+    in
+      curIdx + startIdx
+    end
+
+  fun getLineAbsIdx (startLine, lineGap: LineGap.t) =
+      let
+        val {rightLines, line = curLine, idx = curIdx, ...} = lineGap
+      in
+        case rightLines of
+          rLnHd :: _ =>
+            helpGetLineAbsIdx (curIdx, startLine, curLine, rLnHd)
+        | [] => 
+            (* should never happen *)
+            0
+      end
+
   fun build
     ( startLine, cursorPos, lineGap: LineGap.t
     , windowWidth, windowHeight
@@ -470,30 +512,11 @@ struct
         case (rightStrings, rightLines) of
           (rStrHd :: rStrTl, rLnHd :: _) =>
             let
-              (* get index of line to start building from *)
-              val startIdx =
-                if startLine > curLine then
-                  let
-                    val lnPos = startLine - curLine - 1
-                    val startIdx = Vector.sub (rLnHd, lnPos)
-                  in
-                    if
-                      String.sub (rStrHd, startIdx) = #"\r"
-                      andalso startIdx < String.size rStrHd - 1
-                      andalso String.sub (rStrHd, startIdx + 1) = #"\n"
-                    then 
-                      (* handle \r\n pair *) 
-                      startIdx + 2
-                    else startIdx + 1
-                  end
-                else
-                  0
+              (* get relative index of line to start building from *)
+              val startIdx = helpGetLineStartIdx (startLine, curLine, rLnHd)
+              (* get absolute idx of line *)
               val absIdx = curIdx + startIdx
 
-              (* todo: make going to absIdx a prerequisite for using this
-               * function *)
-              val searchList = SearchList.goToNum (absIdx, searchList)
-
               val windowData = 
                 { w = windowWidth
                 , h = windowHeight