Merge pull request #7 from kit-ty-kate/ppxlib

Switch from OMP to ppxlib

Author: kit-ty-kate

.travis.yml

@@ -7,8 +7,6 @@ env:
   global:
   - PACKAGE="ppx_getenv"
   matrix:
-  - DISTRO=debian-stable OCAML_VERSION=4.02
-  - DISTRO=debian-stable OCAML_VERSION=4.03
   - DISTRO=debian-stable OCAML_VERSION=4.04
   - DISTRO=debian-stable OCAML_VERSION=4.05
   - DISTRO=debian-stable OCAML_VERSION=4.06

dune-project

@@ -14,7 +14,7 @@
   (synopsis "A sample syntax extension using OCaml's new extension points API")
   (tags ("syntax"))
   (depends
-    (ocaml (>= 4.02.0))
-    (ocaml-migrate-parsetree (>= 1.7.0))
+    (ocaml (>= 4.04.0))
+    (ppxlib (>= 0.9.0))
     (ounit2 :with-test)
     (odoc :with-doc)))

ppx_getenv.opam

@@ -10,8 +10,8 @@ homepage: "https://github.com/ocaml-ppx/ppx_getenv"
 bug-reports: "https://github.com/ocaml-ppx/ppx_getenv/issues"
 depends: [
   "dune" {>= "2.0"}
-  "ocaml" {>= "4.02.0"}
-  "ocaml-migrate-parsetree" {>= "1.7.0"}
+  "ocaml" {>= "4.04.0"}
+  "ppxlib" {>= "0.9.0"}
   "ounit2" {with-test}
   "odoc" {with-doc}
 ]

src/dune

@@ -2,4 +2,4 @@
   (name ppx_getenv)
   (public_name ppx_getenv)
   (kind ppx_rewriter)
-  (libraries ocaml-migrate-parsetree))
+  (libraries ppxlib))

src/ppx_getenv.ml

@@ -1,35 +1,20 @@
-open Migrate_parsetree.OCaml_411.Ast
-let ocaml_version = Migrate_parsetree.Versions.ocaml_411
-
-open Ast_mapper
-open Ast_helper
-open Asttypes
-open Parsetree
+open Ppxlib
+open Ppxlib.Ast_helper
 
 let getenv s = try Sys.getenv s with Not_found -> ""
 
-let getenv_mapper _config _cookies =
-  (* Our getenv_mapper only overrides the handling of expressions in the default mapper. *)
-  { default_mapper with
-    expr = fun mapper expr ->
-      match expr with
-      (* Is this an extension node? *)
-      | { pexp_desc =
-          (* Should have name "getenv". *)
-          Pexp_extension ({ txt = "getenv"; loc }, pstr); _ } ->
-        begin match pstr with
-        | (* Should have a single structure item, which is evaluation of a constant string. *)
-          PStr [{ pstr_desc =
-                  Pstr_eval ({ pexp_loc  = loc;
-                               pexp_desc = Pexp_constant (Pconst_string (sym, s_loc, None)); _ }, _); _ }] ->
-          (* Replace with a constant string with the value from the environment. *)
-          Exp.constant ~loc (Pconst_string (getenv sym, s_loc, None))
-        | _ ->
-          raise (Location.Error (
-                  Location.error ~loc "[%getenv] accepts a string, e.g. [%getenv \"USER\"]"))
-        end
-      (* Delegate to the default mapper. *)
-      | x -> default_mapper.expr mapper x;
-  }
+let expander ~loc ~path:_ = function
+  | (* Should have a single structure item, which is evaluation of a constant string. *)
+    PStr [{ pstr_desc =
+            Pstr_eval ({ pexp_loc  = loc;
+                         pexp_desc = Pexp_constant (Pconst_string (sym, None)); _ }, _); _ }] ->
+      (* Replace with a constant string with the value from the environment. *)
+      Exp.constant ~loc (Pconst_string (getenv sym, None))
+  | _ ->
+      Location.raise_errorf ~loc "[%%getenv] accepts a string, e.g. [%%getenv \"USER\"]"
+
+let extension =
+  Context_free.Rule.extension
+    (Extension.declare "getenv" Expression Ast_pattern.(__) expander)
 
-let () = Migrate_parsetree.Driver.register ~name:"getenv" ocaml_version getenv_mapper
+let () = Ppxlib.Driver.register_transformation ~rules:[extension] "ppx_getenv"