buildDunePackage: new support function; use it to refactor some OCaml derivations

pkgs/development/tools/ocaml/merlin/default.nix

@@ -1,23 +1,17 @@
-{ stdenv, fetchzip, ocaml, findlib, dune, yojson }:
+{ stdenv, fetchzip, buildDunePackage, yojson }:
 
-assert stdenv.lib.versionAtLeast ocaml.version "4.02";
-
-let
+buildDunePackage rec {
+  pname = "merlin";
   version = "3.2.2";
-in
 
-stdenv.mkDerivation {
-
-  name = "merlin-${version}";
+  minimumOCamlVersion = "4.02";
 
   src = fetchzip {
     url = "https://github.com/ocaml/merlin/archive/v${version}.tar.gz";
     sha256 = "15ssgmwdxylbwhld9p1cq8x6kadxyhll5bfyf11dddj6cldna3hb";
   };
 
-  buildInputs = [ ocaml findlib dune yojson ];
-
-  inherit (dune) installPhase;
+  buildInputs = [ yojson ];
 
   meta = with stdenv.lib; {
     description = "An editor-independent tool to ease the development of programs in OCaml";

pkgs/development/tools/ocaml/ocaml-top/default.nix

@@ -1,33 +1,25 @@
-{ stdenv, fetchzip, ncurses
-, ocamlPackages
-, dune
-}:
+{ stdenv, fetchzip, ncurses, ocamlPackages }:
 
-stdenv.mkDerivation rec {
+with ocamlPackages; buildDunePackage rec {
+  pname = "ocaml-top";
   version = "1.1.5";
-  name = "ocaml-top-${version}";
+
   src = fetchzip {
     url = "https://github.com/OCamlPro/ocaml-top/archive/${version}.tar.gz";
     sha256 = "1d4i6aanrafgrgk4mh154k6lkwk0b6mh66rykz33awlf5pfqd8yv";
   };
 
-  buildInputs = [ ncurses dune ]
-  ++ (with ocamlPackages; [ ocaml ocp-build findlib lablgtk ocp-index ]);
+  buildInputs = [ ncurses ocp-build lablgtk ocp-index ];
 
   configurePhase = ''
     export TERM=xterm
     ocp-build -init
   '';
 
-  buildPhase = "jbuilder build";
-
-  inherit (dune) installPhase;
-
   meta = {
     homepage = https://www.typerex.org/ocaml-top.html;
     license = stdenv.lib.licenses.gpl3;
     description = "A simple cross-platform OCaml code editor built for top-level evaluation";
-    platforms = ocamlPackages.ocaml.meta.platforms or [];
     maintainers = with stdenv.lib.maintainers; [ vbgl ];
   };
 }

pkgs/development/tools/ocaml/ocamlformat/default.nix

@@ -1,15 +1,10 @@
-{ stdenv, fetchFromGitHub, ocamlPackages, dune }:
+{ stdenv, fetchFromGitHub, ocamlPackages }:
 
-with ocamlPackages;
-
-if !stdenv.lib.versionAtLeast ocaml.version "4.05"
-then throw "ocamlformat is not available for OCaml ${ocaml.version}"
-else
-
-stdenv.mkDerivation rec {
-  version = "0.8";
+with ocamlPackages; buildDunePackage rec {
   pname = "ocamlformat";
-  name = "${pname}-${version}";
+  version = "0.8";
+
+  minimumOCamlVersion = "4.05";
 
   src = fetchFromGitHub {
     owner = "ocaml-ppx";
@@ -19,9 +14,6 @@ stdenv.mkDerivation rec {
   };
 
   buildInputs = [
-    ocaml
-    dune
-    findlib
     base
     cmdliner
     fpath
@@ -34,17 +26,10 @@ stdenv.mkDerivation rec {
     tools/gen_version.sh src/Version.ml version
   '';
 
-  buildPhase = ''
-    dune build -p ocamlformat
-  '';
-
-  inherit (dune) installPhase;
-
   meta = {
-    homepage = "https://github.com/ocaml-ppx/ocamlformat";
+    inherit (src.meta) homepage;
     description = "Auto-formatter for OCaml code";
     maintainers = [ stdenv.lib.maintainers.Zimmi48 ];
     license = stdenv.lib.licenses.mit;
-    inherit (ocamlPackages.ocaml.meta) platforms;
   };
 }