extract reusable function which can be used when a search string is changed, in NORMAL_SEARCH_MODE

fcore/normal-mode/normal-search-mode-with.sml

@@ -37,4 +37,33 @@ struct
       , cursorIdx = cursorIdx
       }
     end
+
+  fun changeTempSearchString
+    (app: app_type, newBuffer, newStartLine, newMode, newMsgs) =
+    let
+      val
+        { mode = _
+        , buffer = _
+        , searchString
+        , searchList
+        , startLine = _
+        , msgs = _
+        , bufferModifyTime
+        , windowWidth
+        , windowHeight
+        , cursorIdx
+        } = app
+    in
+      { mode = newMode
+      , buffer = newBuffer
+      , startLine = newStartLine
+      , msgs = newMsgs
+      , searchString = searchString
+      , searchList = searchList
+      , bufferModifyTime = bufferModifyTime
+      , windowWidth = windowWidth
+      , windowHeight = windowHeight
+      , cursorIdx = cursorIdx
+      }
+    end
 end