Port multibyte-string-p to rust

rust_src/src/lib.rs

@@ -80,6 +80,7 @@ pub use strings::Fstring_equal;
 pub use strings::Fstring_as_multibyte;
 pub use strings::Fstring_to_multibyte;
 pub use strings::Fstring_to_unibyte;
+pub use strings::Fmultibyte_string_p;
 pub use vectors::Flength;
 pub use vectors::Fsort;
 pub use lists::merge;
@@ -168,6 +169,7 @@ pub extern "C" fn rust_init_syms() {
         defsubr(&*strings::Sstringp);
         defsubr(&*strings::Sbase64_encode_string);
         defsubr(&*strings::Sbase64_decode_string);
+        defsubr(&*strings::Smultibyte_string_p);
         defsubr(&*strings::Sstring_bytes);
         defsubr(&*strings::Sstring_equal);
         defsubr(&*strings::Sstring_as_multibyte);

rust_src/src/strings.rs

@@ -201,3 +201,10 @@ fn string_to_unibyte(string: LispObject) -> LispObject {
         string
     }
 }
+
+/// Return t if OBJECT is a multibyte string.
+/// Return nil if OBJECT is either a unibyte string, or not a string.
+#[lisp_fn]
+fn multibyte_string_p(object: LispObject) -> LispObject {
+    LispObject::from_bool(object.as_string().map_or(false, |s| s.is_multibyte()))
+}

src/data.c

@@ -286,17 +286,6 @@ DEFUN ("vectorp", Fvectorp, Svectorp, 1, 1, 0,
   return Qnil;
 }
 
-DEFUN ("multibyte-string-p", Fmultibyte_string_p, Smultibyte_string_p,
-       1, 1, 0,
-       doc: /* Return t if OBJECT is a multibyte string.
-Return nil if OBJECT is either a unibyte string, or not a string.  */)
-  (Lisp_Object object)
-{
-  if (STRINGP (object) && STRING_MULTIBYTE (object))
-    return Qt;
-  return Qnil;
-}
-
 DEFUN ("char-table-p", Fchar_table_p, Schar_table_p, 1, 1, 0,
        doc: /* Return t if OBJECT is a char-table.  */)
   (Lisp_Object object)
@@ -3187,7 +3176,6 @@ syms_of_data (void)
   defsubr (&Sinteractive_form);
   defsubr (&Stype_of);
   defsubr (&Skeywordp);
-  defsubr (&Smultibyte_string_p);
   defsubr (&Svectorp);
   defsubr (&Schar_table_p);
   defsubr (&Svector_or_char_table_p);