create text builder function to call for normal mode

fcore/text-builder/normal-mode-text-builder.sml

@@ -0,0 +1,115 @@
+structure NormalModeTextBuilder =
+struct
+  structure Utils = TextBuilderUtils
+
+  (* Prerequisite to all functions in this structure: 
+   * - Move buffer to startLine before calling any function. *)
+
+  fun startBuild
+    ( startLine
+    , cursorPos
+    , buffer: LineGap.t
+    , windowWidth
+    , windowHeight
+    , floatWindowWidth
+    , floatWindowHeight
+    , searchList
+    , searchString
+    , visualScrollColumn
+    , acc
+    ) =
+    let
+      val {rightStrings, rightLines, line = curLine, idx = curIdx, ...} = buffer
+    in
+      case (rightStrings, rightLines) of
+        (shd :: stl, lhd :: ltl) =>
+          let
+            (* get relative index of line to start building from *)
+            val strPos =
+              Utils.getRelativeLineStartFromRightHead (startLine, curLine, lhd)
+              + 1
+            (* get absolute idx of line *)
+            val absIdx = curIdx + strPos
+            val searchPos = BinSearch.equalOrMore (absIdx, searchList)
+
+            val env = Utils.initEnv
+              ( windowWidth
+              , windowHeight
+              , floatWindowWidth
+              , floatWindowHeight
+              , searchList
+              , String.size searchString
+              , visualScrollColumn
+              , startLine
+              )
+            val {startX, startY, ...} = env
+          in
+            TextBuilderWithHighlight.build
+              ( strPos
+              , shd
+              , stl
+              , lhd
+              , ltl
+              , startX
+              , startY
+              , 0
+              , startLine
+              , absIdx
+              , cursorPos
+              , env
+              , acc
+              , searchPos
+              )
+          end
+      | (_, _) => acc
+    end
+
+  fun buildWithExisting
+    ( startLine
+    , cursorPos
+    , buffer: LineGap.t
+    , windowWidth
+    , windowHeight
+    , searchList: SearchList.t
+    , searchString
+    , visualScrollColumn
+    , acc
+    ) =
+    startBuild
+      ( startLine
+      , cursorPos
+      , buffer
+      , windowWidth
+      , windowHeight
+      , Real32.fromInt windowWidth
+      , Real32.fromInt windowHeight
+      , searchList
+      , searchString
+      , visualScrollColumn
+      , []
+      )
+
+  fun build
+    ( startLine
+    , cursorPos
+    , buffer: LineGap.t
+    , windowWidth
+    , windowHeight
+    , searchList: SearchList.t
+    , searchString
+    , visualScrollColumn
+    ) =
+    startBuild
+      ( startLine
+      , cursorPos
+      , buffer
+      , windowWidth
+      , windowHeight
+      , Real32.fromInt windowWidth
+      , Real32.fromInt windowHeight
+      , searchList
+      , searchString
+      , visualScrollColumn
+      , []
+      )
+end

fcore/text-builder/text-builder-utils.sml

@@ -235,4 +235,40 @@ struct
   fun advanceSearchPos (absIdx, searchPos, env) =
     if isAfterSearchRange (absIdx, searchPos, env) then searchPos + 1
     else searchPos
+
+  (* gets line start idx, relative to right hd *)
+  fun getRelativeLineStartFromRightHead (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 getAbsoluteLineStartFromRightHead (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 getLineAbsIdxFromBuffer (startLine, buffer: LineGap.t) =
+    let
+      val {rightLines, line = curLine, idx = curIdx, ...} = buffer
+    in
+      case rightLines of
+        rLnHd :: _ =>
+          getAbsoluteLineStartFromRightHead (curIdx, startLine, curLine, rLnHd)
+      | [] =>
+          raise Fail
+            "text-builder-utils.sml 268:\ 
+            \should never call function when at end of buffer"
+    end
 end