amend cursor.sml's 'helpTillNextChr' function to work with new line break scheme, and use it to implement 'delete till' functionality starting with 'dt' (for example, 'dta' deletes till 'a', 'dts'detetes till 's', etc.)

fcore/app-update.sml

@@ -432,7 +432,7 @@ struct
     else
       let
         val buffer = LineGap.goToIdx (cursorIdx, buffer)
-        val otherIdx = fMove (buffer, cursorIdx, chr)
+        val otherIdx = fMove (buffer, cursorIdx, chr) + 1
 
         val low = Int.min (cursorIdx, otherIdx)
         val high = Int.max (cursorIdx, otherIdx)
@@ -574,7 +574,13 @@ struct
       case String.sub (str, strPos + 1) of
         #"t" => 
           (* todo: delete till chr, forwards *)
+          (case newCmd of
+            CHAR_EVENT chr =>
+              deleteToChr (app, 1, Cursor.tillNextChr, chr)
+          | KEY_ESC =>
               clearMode app
+          | RESIZE_EVENT (width, height) => 
+              resizeText (app, width, height))
       | #"T" => 
           (* todo: delete till chr, backwards *)
           clearMode app
@@ -662,9 +668,6 @@ struct
             CHAR_EVENT chr => handleChr (app, count, chr, str)
           | KEY_ESC => clearMode app
           | RESIZE_EVENT (width, height) => resizeText (app, width, height)
-        else if numLength + 1 < String.size str then
-          (* continue parsing. *)
-          parseAfterCount (numLength + 1, str, count, app, newCmd)
         else
           (* continue parsing. *)
           parseAfterCount (numLength, str, count, app, newCmd)

fcore/cursor.sml

@@ -1264,12 +1264,15 @@ struct
           (* tl is empty; just return absIdx *) 
           absIdx
 
-  fun helpTillNextChr (strPos, str, absIdx, stl, ltl, origIdx, findChr, lastNonLine) =
+  fun helpTillNextChr 
+    ( strPos, str, absIdx, stl, ltl
+    , origIdx, findChr, lastNonLine, lastLine
+    ) =
       if strPos = String.size str then
         case (stl, ltl) of
           (shd :: stl, lhd :: ltl) => 
             helpTillNextChr 
-            (0, shd, absIdx, stl, ltl, origIdx, findChr, lastNonLine)
+              (0, shd, absIdx, stl, ltl, origIdx, findChr, lastNonLine, lastLine)
         | (_, _) => 
             origIdx
       else 
@@ -1277,35 +1280,46 @@ struct
           val chr = String.sub (str, strPos)
         in
           if chr = findChr then
+            if lastLine = lastNonLine + 1 then
+              (* graphical-chr -> \n
+               * so return graphical-chr *)
               lastNonLine
+            else
+              Int.max (lastLine, lastNonLine)
           else
             let
+              val lastLine = 
+                if chr = #"\n" then
+                  absIdx
+                else
+                  lastLine
               val lastNonLine =
-              if chr = #"\n" orelse chr = #"\r" then
+                if chr = #"\n" then
                   lastNonLine
                 else
                   absIdx
             in
               helpTillNextChr
-              (strPos + 1, str, absIdx + 1, stl, ltl, origIdx, findChr, lastNonLine)
+                ( strPos + 1, str, absIdx + 1, stl, ltl
+                , origIdx, findChr, lastNonLine, lastLine
+                )
             end
         end
 
   fun startTillNextChr (shd, strIdx, absIdx, stl, ltl, findChr) =
     (* we want to start iterating from next char after strIdx *)
-    if strIdx - 1 < String.size shd then
+    if strIdx + 1 < String.size shd then
       helpTillNextChr 
-        (strIdx + 1, shd, absIdx + 1, stl, ltl, absIdx, findChr, absIdx)
+        (strIdx + 1, shd, absIdx + 1, stl, ltl, absIdx, findChr, absIdx, absIdx)
     else
       case (stl, ltl) of
         (stlhd :: stltl, ltlhd :: ltltl) =>
           helpTillNextChr
-            (0, stlhd, absIdx + 1, stltl, ltltl, absIdx, findChr, absIdx)
+            (0, stlhd, absIdx + 1, stltl, ltltl, absIdx, findChr, absIdx, absIdx)
       | (_, _) => 
           (* tl is empty; just return absIdx *) 
           absIdx
 
-
   fun nextChr (lineGap: LineGap.t, cursorIdx, chr, fStart) =
     let
       val {rightStrings, rightLines, idx = bufferIdx, ...} = lineGap
@@ -1328,7 +1342,7 @@ struct
                      val strIdx = strIdx - String.size shd
                    in 
                      fStart
-                       (shd, strIdx, cursorIdx, stltl, ltltl, chr)
+                       (stlhd, strIdx, cursorIdx, stltl, ltltl, chr)
                    end
                | (_, _) => cursorIdx)
           end

temp.txt

@@ -1,5 +1,5 @@
 signature TEXT_BUILDER =
-sig aaron baron carrot durian
+aaron baron carrot durian
   (* Prerequisite: LineGap is moved to requested line first. *)
   val build: int * int * LineGap.t * int * int
              -> MailboxType.t list