ocamlPackages.yojson: 1.2.3 -> 1.3.3

pkgs/development/ocaml-modules/yojson/default.nix

···
 { stdenv, fetchzip, ocaml, findlib, cppo, easy-format, biniou }:
 let
   pname = "yojson";
-  version = "1.2.3";
+  param =
+  if stdenv.lib.versionAtLeast ocaml.version "4.01" then {
+    version = "1.3.3";
+    sha256 = "02l11facbr6bxrxq95vrcp1dxapp02kv7g4gq8rm62pb3dj5c6g7";
+  } else {
+    version = "1.2.3";
+    sha256 = "10dvkndgwanvw4agbjln7kgb1n9s6lii7jw82kwxczl5rd1sgmvl";
+  };
 in
 stdenv.mkDerivation {
 
-  name = "ocaml-${pname}-${version}";
+  name = "ocaml${ocaml.version}-${pname}-${param.version}";
 
   src = fetchzip {
-    url = "https://github.com/mjambon/${pname}/archive/v${version}.tar.gz";
-    sha256 = "10dvkndgwanvw4agbjln7kgb1n9s6lii7jw82kwxczl5rd1sgmvl";
+    url = "https://github.com/mjambon/${pname}/archive/v${param.version}.tar.gz";
+    inherit (param) sha256;
   };
 
   buildInputs = [ ocaml findlib ];