feat(jid): use uchars for JID parsing

1 files changed, 19 insertions, 35 deletions

diff --git a/lib/jid.ml b/lib/jid.ml
index b06a00c..ec24a30 100644
--- a/lib/jid.ml
+++ b/lib/jid.ml
@@ -29,41 +29,25 @@ let string_of_uchars (u : uchars) =
   List.iter (Buffer.add_utf_8_uchar buf) u;
   Buffer.to_bytes buf |> String.of_bytes
 
-let of_string (jid : string) : t =
-  let open Uchar in
-  let len = String.length jid in
-  let rec to_localpart i =
-    if i <= 0 then
-      None
-    else
-      let c = String.get_utf_8_uchar jid i in
-      if not (utf_decode_is_valid c)
-      then raise InvalidUTF8
-      else
-        let k = utf_decode_length c in
-        match utf_decode_uchar c |> to_char with
-        | '@' -> Some (i + 1)
-        | _ -> to_localpart (i - k)
-  and to_resourcepart i =
-    if i >= len then
-      None
-    else
-      let c = String.get_utf_8_uchar jid i in
-      if not (utf_decode_is_valid c)
-      then raise InvalidUTF8
-      else
-        let k = utf_decode_length c in
-        match utf_decode_uchar c |> to_char with
-        | '/' -> Some i
-        | _ -> to_resourcepart (i + k)
-  in let r = to_resourcepart 0 in
-     let rv = Option.value ~default:len r in
-     let l = to_localpart (rv-1) in
-     let lv = Option.value ~default:0 l in
-     {
-       localpart = Option.map (fun i -> String.sub jid 0 (i-1)) l;
-       resourcepart = Option.map (fun i -> String.sub jid (i+1) (len-i-1)) r;
-       domainpart = String.sub jid lv (rv-lv);
+let of_string (jid : uchars) : t =
+  let open List in
+  let dend, resourcepart =
+    find_mapi (fun i c ->
+        if c = Uchar.of_char '/'
+        then Some (i, drop i jid |> string_of_uchars)
+        else None) jid
+    |> Option.fold ~none:(length jid, None) ~some:(fun (i, s) -> i, Some s)
+  and dstart, localpart =
+    rev jid
+    |> find_mapi (fun i c ->
+           if c = Uchar.of_char '@'
+           then Some (i, take i jid |> rev |> string_of_uchars)
+           else None)
+    |> Option.fold ~none:(0, None) ~some:(fun (i, s) -> i, Some s)
+  in {
+       localpart;
+       resourcepart;
+       domainpart = drop dstart jid |> take (dend-dstart) |> string_of_uchars
      }
 
 let to_string ({ localpart; domainpart; resourcepart } : t) =