use concurrency for rebuilding search list after deletion so we don't block main thread on very, very large files

fcore/app-update.sml

@@ -9,6 +9,14 @@ struct
   fun clearMode app =
     AppWith.mode (app, NORMAL_MODE "", [])
 
+  fun withSearchList (app: app_type, searchList) =
+    let
+      val {buffer, searchString, cursorIdx, ...} = app
+      val app = AppWith.searchList (app, searchList, buffer, searchString)
+    in
+      Finish.buildTextAndClear (app, buffer, cursorIdx, searchList, [])
+    end
+
   fun resizeText (app: app_type, newWidth, newHeight) =
     let
       val
@@ -33,6 +41,7 @@ struct
         , newHeight
         , searchList
         , searchString
+        , []
         )
     in
       AppWith.bufferAndSize
@@ -44,7 +53,8 @@ struct
    * where the cursor may possibly jump off window by a wide marigin.
    * Since the cursor may move away a lot, it is best to recenter.
    * *)
-  fun buildTextAndClearAfterChr (app: app_type, buffer, cursorIdx, searchList) =
+  fun buildTextAndClearAfterChr
+    (app: app_type, buffer, cursorIdx, searchList, initialMsg) =
     let
       val {windowWidth, windowHeight, startLine, searchString, ...} = app
 
@@ -68,6 +78,7 @@ struct
         , windowHeight
         , searchList
         , searchString
+        , []
         )
 
       val mode = NORMAL_MODE ""
@@ -104,6 +115,7 @@ struct
         , windowHeight
         , searchList
         , searchString
+        , []
         )
     in
       AppWith.bufferAndCursorIdx
@@ -129,6 +141,7 @@ struct
         , windowHeight
         , searchList
         , searchString
+        , []
         )
 
       val mode = NORMAL_MODE ""
@@ -169,6 +182,7 @@ struct
         , windowHeight
         , searchList
         , searchString
+        , []
         )
 
       val mode = NORMAL_MODE ""
@@ -211,6 +225,7 @@ struct
           , windowHeight
           , searchList
           , searchString
+          , []
           )
 
         val mode = NORMAL_MODE ""
@@ -253,6 +268,7 @@ struct
             , windowHeight
             , searchList
             , searchString
+            , []
             )
         in
           AppWith.bufferAndCursorIdx
@@ -283,6 +299,7 @@ struct
             , windowHeight
             , searchList
             , searchString
+            , []
             )
         in
           AppWith.bufferAndCursorIdx
@@ -309,12 +326,12 @@ struct
       val buffer = LineGap.goToIdx (cursorIdx, buffer)
       val cursorIdx = Cursor.firstNonSpaceChr (buffer, cursorIdx)
     in
-      Finish.buildTextAndClear (app, buffer, cursorIdx, #searchList app)
+      Finish.buildTextAndClear (app, buffer, cursorIdx, #searchList app, [])
     end
 
   fun helpMoveToChr (app: app_type, buffer, cursorIdx, count, fMove, chr) =
     if count = 0 then
-      buildTextAndClearAfterChr (app, buffer, cursorIdx, #searchList app)
+      buildTextAndClearAfterChr (app, buffer, cursorIdx, #searchList app, [])
     else
       let
         (* move LineGap to cursorIdx, which is necessary for finding newCursorIdx *)
@@ -335,6 +352,7 @@ struct
       CHAR_EVENT chr => moveToChr (app, count, fMove, chr)
     | KEY_ESC => clearMode app
     | RESIZE_EVENT (width, height) => resizeText (app, width, height)
+    | WITH_SEARCH_LIST searchList => withSearchList (app, searchList)
 
   fun handleGo (count, app, newCmd) =
     case newCmd of
@@ -346,12 +364,19 @@ struct
          | _ => clearMode app)
     | KEY_ESC => clearMode app
     | RESIZE_EVENT (width, height) => resizeText (app, width, height)
+    | WITH_SEARCH_LIST searchList => withSearchList (app, searchList)
 
   (* text-delete functions *)
   (** equivalent of vi's 'x' command **)
-  fun helpRemoveChr (app: app_type, buffer, searchList, cursorIdx, count) =
+  fun helpRemoveChr (app: app_type, buffer, cursorIdx, count) =
     if count = 0 then
-      Finish.buildTextAndClear (app, buffer, cursorIdx, searchList)
+      let
+        val buffer = LineGap.goToEnd buffer
+        val initialMsg = [SEARCH (buffer, #searchString app)]
+      in
+        Finish.buildTextAndClear
+          (app, buffer, cursorIdx, SearchList.empty, initialMsg)
+      end
     else
       let
         val buffer = LineGap.goToIdx (cursorIdx, buffer)
@@ -374,9 +399,9 @@ 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, searchList, cursorIdx, 0)
+          helpRemoveChr (app, buffer, cursorIdx, 0)
         else if cursorIsStart then
-          helpRemoveChr (app, buffer, searchList, cursorIdx, 0)
+          helpRemoveChr (app, buffer, cursorIdx, 0)
         else if nextIsEnd then
           let
             (* delete char at cursor and then decrement cursorIdx by 1
@@ -384,8 +409,6 @@ struct
             val searchString = #searchString app
             val buffer = LineGap.delete (cursorIdx, 1, buffer)
 
-            val (buffer, searchList) = SearchList.build (buffer, searchString)
-
             val cursorIdx =
               if
                 Cursor.isPrevChrStartOfLine (buffer, cursorIdx)
@@ -393,21 +416,19 @@ struct
               then cursorIdx
               else cursorIdx - 1
           in
-            helpRemoveChr (app, buffer, searchList, cursorIdx, count - 1)
+            helpRemoveChr (app, buffer, cursorIdx, count - 1)
           end
         else
           let
             val searchString = #searchString app
             val buffer = LineGap.delete (cursorIdx, 1, buffer)
-
-            val (buffer, searchList) = SearchList.build (buffer, searchString)
           in
-            helpRemoveChr (app, buffer, searchList, cursorIdx, count - 1)
+            helpRemoveChr (app, buffer, cursorIdx, count - 1)
           end
       end
 
   fun removeChr (app: app_type, count) =
-    helpRemoveChr (app, #buffer app, #searchList app, #cursorIdx app, count)
+    helpRemoveChr (app, #buffer app, #cursorIdx app, count)
 
   fun helpDelete (app: app_type, buffer, cursorIdx, otherIdx, count, fMove) =
     (* As a small optimisation to reduce allocations, 
@@ -426,8 +447,9 @@ struct
 
         val buffer = LineGap.delete (low, length, buffer)
 
+        val buffer = LineGap.goToEnd buffer
         val searchString = #searchString app
-        val (buffer, searchList) = SearchList.build (buffer, searchString)
+        val initialMsg = [SEARCH (buffer, searchString)]
 
         (* If we have deleted from the buffer so that cursorIdx
         * is no longer a valid idx,
@@ -435,7 +457,8 @@ struct
         val buffer = LineGap.goToIdx (low, buffer)
         val cursorIdx = Cursor.clipIdx (buffer, low)
       in
-        Finish.buildTextAndClear (app, buffer, cursorIdx, searchList)
+        Finish.buildTextAndClear
+          (app, buffer, cursorIdx, SearchList.empty, initialMsg)
       end
     else
       let
@@ -463,11 +486,12 @@ struct
 
       val buffer = LineGap.delete (low, length, buffer)
 
-      val (buffer, searchList) = SearchList.build (buffer, searchString)
+      val buffer = LineGap.goToEnd buffer
+      val initialMsg = [SEARCH (buffer, searchString)]
 
       val buffer = LineGap.goToIdx (low, buffer)
     in
-      Finish.buildTextAndClear (app, buffer, low, searchList)
+      Finish.buildTextAndClear (app, buffer, low, SearchList.empty, initialMsg)
     end
 
   fun deleteToEndOfLine (app: app_type) =
@@ -489,12 +513,8 @@ struct
           val lastChr = Cursor.viDlr (buffer, cursorIdx, 1)
           val length = lastChr - cursorIdx
           val buffer = LineGap.delete (cursorIdx, length, buffer)
-
-          (* delete from searchList and map *)
-          val searchString = #searchString app
-          val (buffer, searchList) = SearchList.build (buffer, searchString)
         in
-          helpRemoveChr (app, buffer, searchList, cursorIdx, 1)
+          helpRemoveChr (app, buffer, cursorIdx, 1)
         end
     end
 
@@ -509,11 +529,13 @@ struct
       val length = finishIdx - startIdx
       val buffer = LineGap.delete (startIdx, length, buffer)
 
-      val (buffer, searchList) = SearchList.build (buffer, searchString)
+      val buffer = LineGap.goToEnd buffer
+      val initialMsg = [SEARCH (buffer, searchString)]
 
       val buffer = LineGap.goToIdx (startIdx, buffer)
     in
-      Finish.buildTextAndClear (app, buffer, startIdx, searchList)
+      Finish.buildTextAndClear
+        (app, buffer, startIdx, SearchList.empty, initialMsg)
     end
 
   fun helpDeleteLineBack (app, buffer, low, high, count) =
@@ -523,12 +545,14 @@ struct
         val length = high - low
         val buffer = LineGap.delete (low, length, buffer)
 
+        val buffer = LineGap.goToEnd buffer
         val searchString = #searchString app
-        val (buffer, searchList) = SearchList.build (buffer, searchString)
+        val initialMsg = [SEARCH (buffer, searchString)]
 
         val buffer = LineGap.goToIdx (low, buffer)
       in
-        Finish.buildTextAndClear (app, buffer, low, searchList)
+        Finish.buildTextAndClear
+          (app, buffer, low, SearchList.empty, initialMsg)
       end
     else
       let
@@ -575,9 +599,11 @@ struct
       val length = high - low
 
       val buffer = LineGap.delete (low, length, buffer)
-      val (buffer, searchList) = SearchList.build (buffer, searchString)
+
+      val buffer = LineGap.goToEnd buffer
+      val initialMsg = [SEARCH (buffer, searchString)]
     in
-      Finish.buildTextAndClear (app, buffer, low, searchList)
+      Finish.buildTextAndClear (app, buffer, low, SearchList.empty, initialMsg)
     end
 
   fun helpDeleteToChr
@@ -589,10 +615,12 @@ struct
         val length = high - low
         val buffer = LineGap.delete (low, length, buffer)
 
+        val buffer = LineGap.goToEnd buffer
         val searchString = #searchString app
-        val (buffer, searchList) = SearchList.build (buffer, searchString)
+        val initialMsg = [SEARCH (buffer, searchString)]
       in
-        buildTextAndClearAfterChr (app, buffer, low, searchList)
+        buildTextAndClearAfterChr
+          (app, buffer, low, SearchList.empty, initialMsg)
       end
     else
       let
@@ -625,6 +653,9 @@ struct
       val buffer = LineGap.delete (0, cursorIdx, buffer)
       val (buffer, searchList) = SearchList.build (buffer, searchString)
 
+      val buffer = LineGap.goToEnd buffer
+      val initialMsg = [SEARCH (buffer, #searchString app)]
+
       val cursorIdx = 0
       val startLine = 0
       val buffer = LineGap.goToIdx (cursorIdx, buffer)
@@ -637,6 +668,7 @@ struct
         , windowHeight
         , searchList
         , searchString
+        , initialMsg
         )
 
       val mode = NORMAL_MODE ""
@@ -767,6 +799,7 @@ struct
            | _ => clearMode app)
       | KEY_ESC => clearMode app
       | RESIZE_EVENT (width, height) => resizeText (app, width, height)
+      | WITH_SEARCH_LIST searchList => withSearchList (app, searchList)
     else
       (* have to continue parsing string *)
       case String.sub (str, strPos + 1) of
@@ -776,27 +809,31 @@ struct
              CHAR_EVENT chr =>
                deleteToChr (app, 1, Cursor.tillNextChr, op+, chr)
            | KEY_ESC => clearMode app
-           | RESIZE_EVENT (width, height) => resizeText (app, width, height))
+           | RESIZE_EVENT (width, height) => resizeText (app, width, height)
+           | WITH_SEARCH_LIST searchList => withSearchList (app, searchList))
       | #"T" =>
           (* delete till chr, backwards *)
           (case newCmd of
              CHAR_EVENT chr =>
                deleteToChr (app, 1, Cursor.tillPrevChr, op-, chr)
            | KEY_ESC => clearMode app
-           | RESIZE_EVENT (width, height) => resizeText (app, width, height))
+           | RESIZE_EVENT (width, height) => resizeText (app, width, height)
+           | WITH_SEARCH_LIST searchList => withSearchList (app, searchList))
       | #"f" =>
           (case newCmd of
              CHAR_EVENT chr =>
                deleteToChr (app, count, Cursor.toNextChr, op+, chr)
            | KEY_ESC => clearMode app
-           | RESIZE_EVENT (width, height) => resizeText (app, width, height))
+           | RESIZE_EVENT (width, height) => resizeText (app, width, height)
+           | WITH_SEARCH_LIST searchList => withSearchList (app, searchList))
       | #"F" =>
           (* delete to chr, backwards *)
           (case newCmd of
              CHAR_EVENT chr =>
                deleteToChr (app, count, Cursor.toPrevChr, op-, chr)
            | KEY_ESC => clearMode app
-           | RESIZE_EVENT (width, height) => resizeText (app, width, height))
+           | RESIZE_EVENT (width, height) => resizeText (app, width, height)
+           | WITH_SEARCH_LIST searchList => withSearchList (app, searchList))
       | #"g" =>
           (* same events as handleGo *)
           (case newCmd of
@@ -807,7 +844,8 @@ struct
                 | #"g" => deleteToStart app
                 | _ => clearMode app)
            | KEY_ESC => clearMode app
-           | RESIZE_EVENT (width, height) => resizeText (app, width, height))
+           | RESIZE_EVENT (width, height) => resizeText (app, width, height)
+           | WITH_SEARCH_LIST searchList => withSearchList (app, searchList))
       | _ => clearMode app
 
   (* useful reference as list of non-terminal commands *)
@@ -849,6 +887,7 @@ struct
         CHAR_EVENT chr => handleChr (app, 1, chr, str)
       | KEY_ESC => clearMode app
       | RESIZE_EVENT (width, height) => resizeText (app, width, height)
+      | WITH_SEARCH_LIST searchList => withSearchList (app, searchList)
     else if String.size str = 1 then
       case newCmd of
         CHAR_EVENT chr =>
@@ -857,6 +896,7 @@ struct
            | NONE => parseAfterCount (0, str, 1, app, newCmd))
       | KEY_ESC => clearMode app
       | RESIZE_EVENT (width, height) => resizeText (app, width, height)
+      | WITH_SEARCH_LIST searchList => withSearchList (app, searchList)
     else
       let
         val numLength = getNumLength (0, str)
@@ -872,6 +912,7 @@ struct
             CHAR_EVENT chr => handleChr (app, count, chr, str)
           | KEY_ESC => clearMode app
           | RESIZE_EVENT (width, height) => resizeText (app, width, height)
+          | WITH_SEARCH_LIST searchList => withSearchList (app, searchList)
         else
           (* continue parsing. *)
           parseAfterCount (numLength, str, count, app, newCmd)

fcore/finish.sml

@@ -2,7 +2,7 @@ structure Finish =
 struct
   open AppType
 
-  fun buildTextAndClear (app: app_type, buffer, cursorIdx, searchList) =
+  fun buildTextAndClear (app: app_type, buffer, cursorIdx, searchList, msgs) =
     let
       val {windowWidth, windowHeight, startLine, searchString, ...} = app
 
@@ -18,7 +18,7 @@ struct
       val buffer = LineGap.goToLine (startLine, buffer)
       val lineIdx = TextBuilder.getLineAbsIdx (startLine, buffer)
 
-      val drawMsg = TextBuilder.build
+      val msgs = TextBuilder.build
         ( startLine
         , cursorIdx
         , buffer
@@ -26,11 +26,12 @@ struct
         , windowHeight
         , searchList
         , searchString
+        , msgs
         )
 
       val mode = NORMAL_MODE ""
     in
       AppWith.bufferAndCursorIdx
-        (app, buffer, cursorIdx, mode, startLine, searchList, drawMsg)
+        (app, buffer, cursorIdx, mode, startLine, searchList, msgs)
     end
 end

fcore/move.sml

@@ -12,7 +12,7 @@ functor MakeMove(Fn: MOVE): MAKE_MOVE =
 struct
   fun helpMove (app: AppType.app_type, buffer, cursorIdx, count) =
     if count = 0 then
-      Finish.buildTextAndClear (app, buffer, cursorIdx, #searchList app)
+      Finish.buildTextAndClear (app, buffer, cursorIdx, #searchList app, [])
     else
       (* move LineGap to cursorIdx, which is necessary for finding newCursorIdx *)
       let
@@ -62,7 +62,7 @@ struct
       val buffer = LineGap.goToIdx (cursorIdx, buffer)
       val cursorIdx = Fn.fMove (buffer, cursorIdx, count)
     in
-      Finish.buildTextAndClear (app, buffer, cursorIdx, #searchList app)
+      Finish.buildTextAndClear (app, buffer, cursorIdx, #searchList app, [])
     end
 end
 

fcore/text-builder.sml

@@ -4,43 +4,22 @@ sig
   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
+  val build:
-             -> MailboxType.t list
+    int
+    * int
+    * LineGap.t
+    * int
+    * int
+    * SearchList.t
+    * string
+    * MailboxType.t list
+    -> MailboxType.t list
 end
 
 structure TextBuilder :> TEXT_BUILDER =
 struct
   open TextConstants
 
-  fun accToDrawMsg (textAcc, cursorAcc, bgAcc) =
-    let
-      open MailboxType
-      open DrawMsg
-
-      val textAcc = Vector.concat textAcc
-      val bgAcc = Vector.concat bgAcc
-
-      val textMsg = REDRAW_TEXT textAcc
-      val cursorMsg = REDRAW_CURSOR cursorAcc
-      val bgMsg = REDRAW_BG bgAcc
-    in
-      [DRAW bgMsg, DRAW textMsg, DRAW cursorMsg]
-    end
-
-  (* builds text from a string with char-wrap.
-   * char-wrap is a similar concept to word-wrap, 
-   * but it breaks on character in the middle of a word.
-   *
-   * Will likely want multiple versions of these two mutually recursive
-   * functions for each selection and cursor type:
-   * cursor over an individual character, 
-   * range selection where multiple characters are selected, etc.
-   *
-   * Todo: 
-   * - Possibly add visual horizontal indentation when char-wrap occurs
-   *   on an indented line *)
-  (* same as buildTextStringAfterCursor, except this keeps track of absolute
-   * index and cursor pos too *)
   type env_data =
     { r: Real32.real
     , g: Real32.real
@@ -57,8 +36,40 @@ struct
     (* fw/fh = float window width and float window height *)
     , fw: Real32.real
     , fh: Real32.real
+    , msgs: MailboxType.t list
     }
 
+  fun accToDrawMsg (textAcc, cursorAcc, bgAcc, env: env_data) =
+    let
+      open MailboxType
+      open DrawMsg
+
+      val msgs = #msgs env
+
+      val textAcc = Vector.concat textAcc
+      val bgAcc = Vector.concat bgAcc
+
+      val textMsg = REDRAW_TEXT textAcc
+      val cursorMsg = REDRAW_CURSOR cursorAcc
+      val bgMsg = REDRAW_BG bgAcc
+    in
+      DRAW bgMsg :: DRAW textMsg :: DRAW cursorMsg :: msgs
+    end
+
+  (* builds text from a string with char-wrap.
+   * char-wrap is a similar concept to word-wrap, 
+   * but it breaks on character in the middle of a word.
+   *
+   * Will likely want multiple versions of these two mutually recursive
+   * functions for each selection and cursor type:
+   * cursor over an individual character, 
+   * range selection where multiple characters are selected, etc.
+   *
+   * Todo: 
+   * - Possibly add visual horizontal indentation when char-wrap occurs
+   *   on an indented line *)
+  (* same as buildTextStringAfterCursor, except this keeps track of absolute
+   * index and cursor pos too *)
   fun buildTextString
     ( pos
     , str
@@ -159,7 +170,7 @@ struct
                   )
               end
           else
-            accToDrawMsg (acc, cursorAcc, bgAcc)
+            accToDrawMsg (acc, cursorAcc, bgAcc, env)
       | chr =>
           let
             val chrFun = Vector.sub (CozetteAscii.asciiTable, Char.ord chr)
@@ -213,7 +224,7 @@ struct
                     )
                 end
               else
-                accToDrawMsg (acc, cursorAcc, bgAcc)
+                accToDrawMsg (acc, cursorAcc, bgAcc, env)
             else
               (* equal to cursor *)
               let
@@ -278,7 +289,7 @@ struct
                       )
                   end
                 else
-                  accToDrawMsg (acc, cursorAcc, bgAcc)
+                  accToDrawMsg (acc, cursorAcc, bgAcc, env)
               end
           end
     else
@@ -299,7 +310,7 @@ struct
             , bgAcc
             , env
             )
-      | [] => accToDrawMsg (acc, cursorAcc, bgAcc)
+      | [] => accToDrawMsg (acc, cursorAcc, bgAcc, env)
 
   fun isInSearchRange (absIdx, searchPos, searchHd, searchLen) =
     let val searchIdx = Vector.sub (searchHd, searchPos)
@@ -329,21 +340,21 @@ struct
     , searchLen
     ) =
     if searchPos = Vector.length searchHd then
-          (* exhausted search list so call normal build function *)
+      (* exhausted search list so call normal build function *)
-          buildTextString
+      buildTextString
-            ( pos
+        ( pos
-            , str
+        , str
-            , acc
+        , acc
-            , posX
+        , posX
-            , posY
+        , posY
-            , startX
+        , startX
-            , tl
+        , tl
-            , absIdx
+        , absIdx
-            , cursorPos
+        , cursorPos
-            , cursorAcc
+        , cursorAcc
-            , bgAcc
+        , bgAcc
-            , env
+        , env
-            )
+        )
     else if pos < String.size str then
       case String.sub (str, pos) of
         #" " =>
@@ -474,7 +485,7 @@ struct
                   )
               end
           else
-            accToDrawMsg (acc, cursorAcc, bgAcc)
+            accToDrawMsg (acc, cursorAcc, bgAcc, env)
       | chr =>
           let
             val chrFun = Vector.sub (CozetteAscii.asciiTable, Char.ord chr)
@@ -582,7 +593,7 @@ struct
                     )
                 end
               else
-                accToDrawMsg (acc, cursorAcc, bgAcc)
+                accToDrawMsg (acc, cursorAcc, bgAcc, env)
             else
               (* equal to cursor *)
               let
@@ -652,7 +663,7 @@ struct
                       )
                   end
                 else
-                  accToDrawMsg (acc, cursorAcc, bgAcc)
+                  accToDrawMsg (acc, cursorAcc, bgAcc, env)
               end
           end
     else
@@ -676,7 +687,7 @@ struct
             , searchPos
             , searchLen
             )
-      | [] => accToDrawMsg (acc, cursorAcc, bgAcc)
+      | [] => accToDrawMsg (acc, cursorAcc, bgAcc, env)
 
   (* gets line start idx, relative to right hd *)
   fun helpGetLineStartIdx (startLine, curLine, rLnHd) =
@@ -718,6 +729,7 @@ struct
     , windowHeight
     , searchList: SearchList.t
     , searchString
+    , msgs
     ) =
     let
       val {rightStrings, rightLines, line = curLine, idx = curIdx, ...} =
@@ -742,44 +754,45 @@ struct
               , hr = 0.211
               , hg = 0.219
               , hb = 0.25
+              , msgs = msgs
               }
 
             val cursorAcc = Vector.fromList []
             val searchPos = BinSearch.equalOrMore (absIdx, searchList)
           in
             if searchPos < Vector.length searchList then
-                   buildTextStringSearch
+              buildTextStringSearch
-                     ( startIdx
+                ( startIdx
-                     , rStrHd
+                , rStrHd
-                     , []
+                , []
-                     , 5
+                , 5
-                     , 5
+                , 5
-                     , 5
+                , 5
-                     , rStrTl
+                , rStrTl
-                     , absIdx
+                , absIdx
-                     , cursorPos
+                , cursorPos
-                     , cursorAcc
+                , cursorAcc
-                     , []
+                , []
-                     , env
+                , env
-                     , searchList
+                , searchList
-                     , searchPos
+                , searchPos
-                     , String.size searchString
+                , String.size searchString
-                     )
+                )
             else
-                 buildTextString
+              buildTextString
-                   ( startIdx
+                ( startIdx
-                   , rStrHd
+                , rStrHd
-                   , []
+                , []
-                   , 5
+                , 5
-                   , 5
+                , 5
-                   , 5
+                , 5
-                   , rStrTl
+                , rStrTl
-                   , absIdx
+                , absIdx
-                   , cursorPos
+                , cursorPos
-                   , cursorAcc
+                , cursorAcc
-                   , []
+                , []
-                   , env
+                , env
-                   )
+                )
           end
       | (_, _) =>
           (* requested line goes beyond the buffer,

message-types/input-msg.sml

@@ -1,2 +1,8 @@
 structure InputMsg =
-struct datatype t = CHAR_EVENT of char | KEY_ESC | RESIZE_EVENT of int * int end
+struct
+  datatype t =
+    CHAR_EVENT of char
+  | KEY_ESC
+  | RESIZE_EVENT of int * int
+  | WITH_SEARCH_LIST of int vector
+end

message-types/mailbox-type.sml

@@ -1 +1,2 @@
-structure MailboxType = struct datatype t = DRAW of DrawMsg.t end
+structure MailboxType =
+struct datatype t = DRAW of DrawMsg.t | SEARCH of LineGap.t * string end

shell/search-thread.sml

@@ -0,0 +1,14 @@
+structure SearchThread =
+struct
+  open CML
+
+  (* Prerequisite to sending message: move buffer to end. *)
+  fun loop (searchMailbox, inputMailbox) =
+    let
+      val (buffer, searchString) = Mailbox.recv searchMailbox
+      val (_, searchList) = SearchList.build (buffer, searchString)
+      val () = Mailbox.send (inputMailbox, InputMsg.WITH_SEARCH_LIST searchList)
+    in
+      loop (searchMailbox, inputMailbox)
+    end
+end

shell/shell.sml

@@ -6,6 +6,7 @@ struct
   (* create mailboxes for CML communication *)
   val inputMailbox = Mailbox.mailbox ()
   val drawMailbox = Mailbox.mailbox ()
+  val searchMailbox = Mailbox.mailbox ()
 
   fun frameBufferSizeCallback (width, height) =
     Mailbox.send (inputMailbox, RESIZE_EVENT (width, height))
@@ -79,7 +80,9 @@ struct
 
       val _ = CML.spawn (fn () => GlDraw.loop (drawMailbox, window))
       val _ = CML.spawn (fn () =>
-        UpdateThread.loop (app, inputMailbox, drawMailbox))
+        UpdateThread.loop (app, inputMailbox, drawMailbox, searchMailbox))
+      val _ = CML.spawn (fn () =>
+        SearchThread.loop (searchMailbox, inputMailbox))
     in
       ()
     end

shell/update-thread.sml

@@ -4,18 +4,21 @@ struct
   open MailboxType
   open InputMsg
 
-  fun sendMsg (msg, drawMailbox) =
+  fun sendMsg (msg, drawMailbox, searchMailbox) =
-    case msg of DRAW msg => Mailbox.send (drawMailbox, msg)
+    case msg of
+      DRAW msg => Mailbox.send (drawMailbox, msg)
+    | SEARCH (buffer, searchString) =>
+        Mailbox.send (searchMailbox, (buffer, searchString))
 
-  fun sendMsgs (msgList, drawMailbox) =
+  fun sendMsgs (msgList, drawMailbox, searchMailbox) =
     case msgList of
       hd :: tl =>
-        let val _ = sendMsg (hd, drawMailbox)
+        let val _ = sendMsg (hd, drawMailbox, searchMailbox)
-        in sendMsgs (tl, drawMailbox)
+        in sendMsgs (tl, drawMailbox, searchMailbox)
         end
     | [] => ()
 
-  fun loop (app: AppType.app_type, inputMailbox, drawMailbox) =
+  fun loop (app: AppType.app_type, inputMailbox, drawMailbox, searchMailbox) =
     let
       val inputMsg = Mailbox.recv inputMailbox
       val () =
@@ -33,8 +36,8 @@ struct
       val app = AppUpdate.update (app, inputMsg)
                 handle e => ExceptionLogger.log e
 
-      val () = sendMsgs (#msgs app, drawMailbox)
+      val () = sendMsgs (#msgs app, drawMailbox, searchMailbox)
     in
-      loop (app, inputMailbox, drawMailbox)
+      loop (app, inputMailbox, drawMailbox, searchMailbox)
     end
 end

shf.mlb

@@ -47,6 +47,7 @@ in
 end
 
 shell/exception-logger.sml
+shell/search-thread.sml
 shell/update-thread.sml
 shell/gl-shaders.sml
 shell/gl-draw.sml