Add predefined types for tagged int8 and int16 (#3347)

added predefined types for int8 and int16, along with modules for them in Stdlib_beta

otherlibs/stdlib_beta/.ocamlformat

@@ -0,0 +1,15 @@
+# Please make a pull request to change this file.
+# Keep the remainder of this file in sync with other .ocamlformat files in this repo.
+assignment-operator=begin-line
+cases-exp-indent=2
+doc-comments=before
+dock-collection-brackets=false
+if-then-else=keyword-first
+module-item-spacing=sparse
+parens-tuple=multi-line-only
+sequence-blank-line=compact
+space-around-lists=false
+space-around-variants=false
+type-decl=sparse
+wrap-comments=true
+version=0.24.1

otherlibs/stdlib_beta/.ocamlformat-enable

@@ -1,3 +1,7 @@
-stdlib_beta.mli
+int8.ml
+int8.mli
+int16.ml
+int16.mli
+int_wrapper.ml
 stdlib_beta.ml
-
+stdlib_beta.mli

otherlibs/stdlib_beta/dune

@@ -24,7 +24,10 @@
    -safe-string
    -strict-formats
    -extension-universe
-   beta))
+   beta
+   -extension
+   small_numbers_beta
+   ))
  (ocamlopt_flags
   (:include %{project_root}/ocamlopt_flags.sexp))
  (library_flags

otherlibs/stdlib_beta/int16.ml

@@ -0,0 +1,30 @@
+(**************************************************************************)
+(*                                                                        *)
+(*                                 OCaml                                  *)
+(*                                                                        *)
+(*                 Jacob Van Buren, Jane Street, New York                 *)
+(*                                                                        *)
+(*   Copyright 2024 Jane Street Group LLC                                 *)
+(*                                                                        *)
+(*   All rights reserved.  This file is distributed under the terms of    *)
+(*   the GNU Lesser General Public License version 2.1, with the          *)
+(*   special exception on linking described in the file LICENSE.          *)
+(*                                                                        *)
+(**************************************************************************)
+
+[@@@ocaml.flambda_o3]
+
+type t = int16
+
+include
+  Int_wrapper.Make
+    (Int_wrapper)
+    (struct
+      type nonrec t = t
+
+      let int_size = 16
+
+      external inject : t -> int = "%identity"
+
+      external unchecked_project : int -> t = "%identity"
+    end)

otherlibs/stdlib_beta/int16.mli

@@ -0,0 +1,24 @@
+(**************************************************************************)
+(*                                                                        *)
+(*                                 OCaml                                  *)
+(*                                                                        *)
+(*                 Jacob Van Buren, Jane Street, New York                 *)
+(*                                                                        *)
+(*   Copyright 2024 Jane Street Group LLC                                 *)
+(*                                                                        *)
+(*   All rights reserved.  This file is distributed under the terms of    *)
+(*   the GNU Lesser General Public License version 2.1, with the          *)
+(*   special exception on linking described in the file LICENSE.          *)
+(*                                                                        *)
+(**************************************************************************)
+
+(** Signed 16-bit integer values.
+
+    These integers are {16} bits wide and use two's complement representation.
+    All operations are taken modulo 2{^16}. They do not fail on overflow. *)
+
+(** The type for 16-bit integer values. *)
+type t = int16 [@@immediate]
+
+(** @inline *)
+include Int_wrapper.S with type t := int16

otherlibs/stdlib_beta/int8.ml

@@ -0,0 +1,30 @@
+(**************************************************************************)
+(*                                                                        *)
+(*                                 OCaml                                  *)
+(*                                                                        *)
+(*                 Jacob Van Buren, Jane Street, New York                 *)
+(*                                                                        *)
+(*   Copyright 2024 Jane Street Group LLC                                 *)
+(*                                                                        *)
+(*   All rights reserved.  This file is distributed under the terms of    *)
+(*   the GNU Lesser General Public License version 2.1, with the          *)
+(*   special exception on linking described in the file LICENSE.          *)
+(*                                                                        *)
+(**************************************************************************)
+
+[@@@ocaml.flambda_o3]
+
+type t = int8
+
+include
+  Int_wrapper.Make
+    (Int_wrapper)
+    (struct
+      type nonrec t = t
+
+      let int_size = 8
+
+      external inject : t -> int = "%identity"
+
+      external unchecked_project : int -> t = "%identity"
+    end)

otherlibs/stdlib_beta/int8.mli

@@ -0,0 +1,24 @@
+(**************************************************************************)
+(*                                                                        *)
+(*                                 OCaml                                  *)
+(*                                                                        *)
+(*                 Jacob Van Buren, Jane Street, New York                 *)
+(*                                                                        *)
+(*   Copyright 2024 Jane Street Group LLC                                 *)
+(*                                                                        *)
+(*   All rights reserved.  This file is distributed under the terms of    *)
+(*   the GNU Lesser General Public License version 2.1, with the          *)
+(*   special exception on linking described in the file LICENSE.          *)
+(*                                                                        *)
+(**************************************************************************)
+
+(** Signed 8-bit integer values.
+
+    These integers are {8} bits wide and use two's complement representation.
+    All operations are taken modulo 2{^8}. They do not fail on overflow. *)
+
+(** The type for 8-bit integer values. *)
+type t = int8 [@@immediate]
+
+(** @inline *)
+include Int_wrapper.S with type t := int8