Add support for the seq package for 4.07+

CHANGES.md

@@ -53,6 +53,8 @@ unreleased
 - Look for jsoo runtime in the same dir as the `js_of_ocaml` binary
   when the ocamlfind package is not available (#1467, @nobj)
 
+- Make the `seq` package available for OCaml >= 4.07 (#1714, @rgrinberg)
+
 1.6.2 (05/12/2018)
 ------------------
 

src/meta.ml

@@ -248,6 +248,7 @@ let builtins ~stdlib_dir ~version:ocaml_version =
   let bytes = dummy "bytes" in
   let result = dummy "result" in
   let uchar = dummy "uchar" in
+  let seq = dummy "seq" in
   let threads =
     { name = Some (Lib_name.of_string_exn ~loc:None "threads")
     ; entries =
@@ -284,6 +285,11 @@ let builtins ~stdlib_dir ~version:ocaml_version =
         uchar :: base
       else
         base in
+    let base =
+      if Ocaml_version.stdlib_includes_seq ocaml_version then
+        seq :: base
+      else
+        base in
     (* We do not rely on an "exists_if" ocamlfind variable,
        because it would produce an error message mentioning
        a "hidden" package (which could be confusing). *)

src/ocaml_version.ml

@@ -34,3 +34,6 @@ let stdlib_includes_uchar version =
 
 let stdlib_includes_bigarray version =
   version >= (4, 07, 0)
+
+let stdlib_includes_seq version =
+  version >= (4, 07, 0)

src/ocaml_version.mli

@@ -35,3 +35,6 @@ val stdlib_includes_uchar : t -> bool
 
 (** Whether the standard library includes the [Bigarray] module *)
 val stdlib_includes_bigarray : t -> bool
+
+(** Whether the standard library includes the [Seq] module *)
+val stdlib_includes_seq : t -> bool