migrate nim pkg to nix

runtimes/default.nix

@@ -30,4 +30,5 @@ args: {
     "perl" = import ./perl.nix args;
     "octave" = import ./octave.nix args;
     "ocaml" = import ./ocaml.nix args;
+    "nim" = import ./nim.nix args;
 }

runtimes/nim.nix

@@ -0,0 +1,32 @@
+{pkgs, piston, ...}:
+let
+    pkg = pkgs.nim; 
+in piston.mkRuntime {
+    language = "nim";
+    version = pkg.version;
+    aliases = [];
+
+    compile = ''
+        ${pkg}/bin/nim --hints:off --out:out --nimcache:./ c "$@"
+        chmod +x out
+    '';
+
+    run = ''
+        shift
+        ./out "$@"
+    '';
+
+    tests = [
+        (piston.mkTest {
+            files = {
+                "test.nim" = ''
+                    echo("OK")
+                '';
+            };
+            args = [];
+            stdin = "";
+            packages = [];
+            main = "test.nim";
+        })
+    ];
+}