initial implementation of building search list

fcore/build-search-list.sml

@@ -0,0 +1,81 @@
+structure BuildSearchList =
+struct
+  fun helpNextMatch (idx, hd, tl, absIdx, searchString, matchedChrs) =
+    if idx = String.size hd then
+      case tl of
+        tlhd :: tltl =>
+          helpNextMatch (0, tlhd, tltl, absIdx, searchString, matchedChrs)
+      | [] => 
+          NONE
+    else
+      let
+        val hdChr = String.sub (hd, idx)
+        val searchChr = String.sub (searchString, matchedChrs)
+      in
+        if hdChr = searchChr then
+          if matchedChrs + 1 = String.size searchString then
+            let
+              val matchedIdx = absIdx - String.size searchString - 1
+            in
+              SOME matchedIdx
+            end
+          else
+            helpNextMatch 
+              (idx + 1, hd, tl, absIdx + 1, searchString, matchedChrs + 1)
+        else
+          helpNextMatch (idx + 1, hd, tl, absIdx + 1, searchString, 0)
+      end
+
+  fun nextMatch (bufferIdx, absIdx, rightStrings, searchString) =
+    case rightStrings of
+      hd :: tl =>
+        let 
+          val strIdx = absIdx - bufferIdx
+        in
+          if strIdx < String.size hd then
+            helpNextMatch (strIdx, hd, tl, absIdx, searchString, 0)
+          else
+            (case tl of
+              tlhd :: tltl =>
+                let
+                  val strIdx = strIdx - String.size hd
+                in
+                  helpNextMatch (strIdx, tlhd, tltl, absIdx, searchString, 0)
+                end
+            | [] => NONE)
+        end
+    | [] => NONE
+
+  fun helpBuild (app, origIdx, absIdx, buffer, searchString, searchList) =
+    let
+      val buffer = LineGap.goToIdx (absIdx, buffer)
+      val {idx = bufferIdx, rightStrings, ...} = buffer
+    in
+      case nextMatch (bufferIdx, absIdx, rightStrings, searchString) of
+        SOME matchedIdx =>
+          let
+            val searchList = SearchList.append (matchedIdx, searchList)
+          in
+            helpBuild 
+              (app, origIdx, matchedIdx, buffer, searchString, searchList)
+          end
+      | NONE =>
+          let
+            val buffer = LineGap.goToIdx (origIdx, buffer)
+            val searchList = SearchList.goToNum (origIdx, searchList)
+          in
+            AppWith.searchListAndBuffer (app, searchList, buffer)
+          end
+    end
+
+  fun build (app, cursorIdx, buffer, searchString) =
+    if String.size searchString > 0 then
+      let
+        val buffer = LineGap.goToStart buffer
+      in
+        helpBuild 
+          (app, cursorIdx, 0, buffer, searchString, SearchList.empty)
+      end
+    else
+      app
+end