Implement Nat.length_nat as an external primitive

ocaml · Oct 26, 2023 · 88f1ed2 · 88f1ed2
1 parent f90804a
commit 88f1ed2
Show file tree

Hide file tree

Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/src/nat.ml b/src/nat.ml
@@ -67,7 +67,7 @@ external lxor_digit_nat: nat -> int -> nat -> int -> unit = "lxor_digit_nat"
 external initialize_nat: unit -> unit = "initialize_nat"
 let _ = initialize_nat()
 
-let length_nat (n : nat) = Obj.size (Obj.repr n) - 1
+external length_nat : nat -> int = "length_nat" [@@noalloc]
 
 let length_of_digit = Sys.word_size;;
 

diff --git a/src/nat.mli b/src/nat.mli
@@ -30,7 +30,7 @@ external nth_digit_nat: nat -> int -> int = "nth_digit_nat"
 external set_digit_nat_native: nat -> int -> nativeint -> unit
                              = "set_digit_nat_native"
 external nth_digit_nat_native: nat -> int -> nativeint = "nth_digit_nat_native"
-val length_nat : nat -> int
+external length_nat : nat -> int = "length_nat" [@@noalloc]
 external num_digits_nat: nat -> int -> int -> int = "num_digits_nat"
 external num_leading_zero_bits_in_digit: nat -> int -> int
                                        = "num_leading_zero_bits_in_digit"