Remove most Str.split

Not needed

Author: chenglou

src/FindFiles.ml

@@ -46,11 +46,11 @@ let isSourceFile name =
   || Filename.check_suffix name ".mli"
 
 let compiledNameSpace name =
-  Str.split (Str.regexp_string "-") name
+  String.split_on_char '-' name
   |> List.map String.capitalize_ascii
   |> String.concat ""
   (* Remove underscores??? Whyyy bucklescript, whyyyy *)
-  |> Str.split (Str.regexp_string "_")
+  |> String.split_on_char '_'
   |> String.concat ""
 
 let compiledBaseName ~namespace name =

src/MarkdownOfOCamldoc.ml

@@ -24,7 +24,7 @@ let sliceToEnd text num =
   if ln <= num then "" else String.sub text num (ln - num)
 
 let stripLeft text =
-  let lines = Str.split (Str.regexp_string "\n") text in
+  let lines = String.split_on_char '\n' text in
   let rec loop lines =
     match lines with
     | [] -> 0
@@ -122,7 +122,7 @@ let convertItem item =
         match String.trim lang = "" with
         | true -> "ml"
         | false ->
-          let parts = Str.split (Str.regexp_string ";") (String.trim lang) in
+          let parts = String.split_on_char ';' (String.trim lang) in
           if
             List.mem "ml" parts || List.mem "ocaml" parts || List.mem "re" parts
             || List.mem "reason" parts

src/Packages.ml

@@ -79,7 +79,7 @@ let newBsPackage rootPath =
                    match item |> Json.string with
                    | None -> opens
                    | Some s -> (
-                     let parts = Utils.split_on_char ' ' s in
+                     let parts = String.split_on_char ' ' s in
                      match parts with
                      | "-open" :: name :: _ -> name :: opens
                      | _ -> opens))

src/PartialParser.ml

@@ -44,7 +44,7 @@ let findCallFromArgument text offset =
         let i1 = skipWhite text (i - 1) in
         let i0 = startOfLident text i1 in
         let funLident = String.sub text i0 (i1 - i0 + 1) in
-        Str.split (Str.regexp_string ".") funLident
+        String.split_on_char '.' funLident
       | ')' -> loop ~i:(i - 1) ~nClosed:(nClosed + 1)
       | _ -> loop ~i:(i - 1) ~nClosed
     else []
@@ -134,7 +134,7 @@ let isLowercaseIdent id =
 let findCompletable text offset =
   let mkPath s =
     let len = String.length s in
-    let parts = Str.split (Str.regexp_string ".") s in
+    let parts = String.split_on_char '.' s in
     let parts =
       match s.[len - 1] = '.' with true -> parts @ [""] | false -> parts
     in
@@ -143,7 +143,7 @@ let findCompletable text offset =
       match findJsxContext text (offset - len - 1) with
       | None -> Cpath parts
       | Some componentName ->
-        Cjsx (Str.split (Str.regexp_string ".") componentName, id))
+        Cjsx (String.split_on_char '.' componentName, id))
     | _ -> Cpath parts
   in
   let mkPipe off partialName =
@@ -200,7 +200,7 @@ let findOpens text offset =
       | [] -> SharedTypes.Tip "place holder"
       | one :: rest -> Nested (one, loop rest)
     in
-    loop (o |> Str.split (Str.regexp_string "."))
+    loop (o |> String.split_on_char '.')
   in
   let add o = opens := (o |> pathOfModuleOpen) :: !opens in
   let maybeOpen i0 =

src/PrepareUtils.ml

@@ -22,7 +22,7 @@ let trimFirst num string =
   | false -> ""
 
 let cleanOffStars doc =
-  let lines = Str.split (Str.regexp_string "\n") doc in
+  let lines = String.split_on_char '\n' doc in
   let rec loop lines =
     match lines with
     | [] -> None

src/Utils.ml

@@ -1,18 +1,3 @@
-(*
-  steal from OCaml stdlib
-  https://github.com/ocaml/ocaml/blob/7c9c210884e1b46f21af5bb4dfab995bb3336cf7/stdlib/string.ml#L205-L214
-*)
-let split_on_char sep s =
-  let open String in
-  let r = ref [] in
-  let j = ref (length s) in
-  for i = length s - 1 downto 0 do
-    if unsafe_get s i = sep then (
-      r := sub s (i + 1) (!j - i - 1) :: !r;
-      j := i)
-  done;
-  sub s 0 !j :: !r
-
 let topLoc fname =
   {
     Location.loc_start =