handle \r\n pair in 'viL' function

fcore/cursor.sml

@@ -12,13 +12,34 @@ struct
             val strIdx = cursorIdx - bufferIdx
           in
             if strIdx < String.size hd - 2 then
-              (* increment if there is a character after where cursor is *)
+              (* increment if there is a character after where cursor is 
-              cursorIdx + 1
+               * but first, check if we are in a \r\n pair; 
+               * if we are, then increment cursor by 2 *)
+              if
+                String.size hd > strIdx + 2
+                andalso String.sub (hd, strIdx + 1) = #"\r"
+                andalso String.sub (hd, strIdx + 2) = #"\n"
+              then
+                (* increment cursor by 2 if we are inside \r\n pair *)
+                cursorIdx + 2
+              else
+                (* inccrement cursor by 1 if we are not inside \r\n pair *)
+                cursorIdx + 1
             else
               (case tl of
                  _ :: _ =>
-                   (* if there is another string after current head, we can increment cursorIdx *)
+                   (* if there is another string after current head, we can increment cursorIdx 
-                   cursorIdx + 1
+                    * however, first we need to check if next string is \r\n pair. *)
+                   if
+                     String.size hd > strIdx + 2
+                     andalso String.sub (hd, strIdx + 1) = #"\r"
+                     andalso String.sub (hd, strIdx + 2) = #"\n"
+                   then
+                     (* increment cursor by 2 if we are inside \r\n pair *)
+                     cursorIdx + 2
+                   else
+                     (* inccrement cursor by 1 if we are not inside \r\n pair *)
+                     cursorIdx + 1
                | _ =>
                    (* if there is no string after current head, return original cursorIdx *)
                    cursorIdx)

fcore/text-builder.sml

@@ -227,7 +227,7 @@ struct
               buildTextStringBeforeCursor
                 ( pos + 2, str, acc, startX, posY + ySpace, startX
                 , windowWidth, windowHeight, fWindowWidth, fWindowHeight
-                , r, g, b, tl, absIdx + 1, cursorPos, hr, hg, hb
+                , r, g, b, tl, absIdx + 2, cursorPos, hr, hg, hb
                 )
             else 
               buildTextStringBeforeCursor
@@ -332,7 +332,7 @@ struct
               buildTextStringWithinCursor
                 ( pos + 2, str, acc, startX, posY + ySpace, startX
                 , windowWidth, windowHeight, fWindowWidth, fWindowHeight
-                , r, g, b, tl, absIdx + 1, cursorPos, cursorAcc, hr, hg, hb
+                , r, g, b, tl, absIdx + 2, cursorPos, cursorAcc, hr, hg, hb
                 )
             else 
               buildTextStringWithinCursor