Port bobp to rust

rust_src/src/editfns.rs

@@ -41,3 +41,11 @@ pub fn eobp() -> LispObject {
     let buffer_ref = ThreadState::current_buffer();
     LispObject::from_bool(buffer_ref.zv() == buffer_ref.pt)
 }
+
+/// Return t if point is at the beginning of the buffer.  If the
+/// buffer is narrowed, this means the beginning of the narrowed part.
+#[lisp_fn]
+pub fn bobp() -> LispObject {
+    let buffer_ref = ThreadState::current_buffer();
+    LispObject::from_bool(buffer_ref.pt == buffer_ref.begv)
+}

rust_src/src/lib.rs

@@ -85,6 +85,7 @@ pub use math::Flss;
 pub use math::Fleq;
 pub use math::arithcompare;
 pub use editfns::Feobp;
+pub use editfns::Fbobp;
 
 // Widely used in the C codebase.
 pub use lists::Fsetcar;
@@ -317,5 +318,6 @@ pub extern "C" fn rust_init_syms() {
         defsubr(&*editfns::Spoint);
         defsubr(&*editfns::Sbuffer_size);
         defsubr(&*editfns::Seobp);
+        defsubr(&*editfns::Sbobp);
     }
 }

src/editfns.c

@@ -1167,16 +1167,6 @@ At the beginning of the buffer or accessible region, return 0.  */)
   return temp;
 }
 
-DEFUN ("bobp", Fbobp, Sbobp, 0, 0, 0,
-       doc: /* Return t if point is at the beginning of the buffer.
-If the buffer is narrowed, this means the beginning of the narrowed part.  */)
-  (void)
-{
-  if (PT == BEGV)
-    return Qt;
-  return Qnil;
-}
-
 DEFUN ("bolp", Fbolp, Sbolp, 0, 0, 0,
        doc: /* Return t if point is at the beginning of a line.  */)
   (void)
@@ -5419,7 +5409,6 @@ functions if all the text being accessed has this property.  */);
   defsubr (&Sposition_bytes);
   defsubr (&Sbyte_to_position);
 
-  defsubr (&Sbobp);
   defsubr (&Sbolp);
   defsubr (&Seolp);
   defsubr (&Sfollowing_char);