Initial commit

Setup a nix flake for an ocaml setup with mruby dependency

src/dune

@@ -0,0 +1,9 @@
+(executable
+ (name main)
+ (libraries ctypes-foreign)
+ (flags     :standard
+            -cclib -Wl,--export-dynamic
+            -cclib -L%{env:MRUBY_LIB=../libs/mruby/build/host/lib}
+            -cclib -Wl,--whole-archive
+            -cclib -lmruby
+            -cclib -Wl,--no-whole-archive))

src/main.ml

@@ -0,0 +1,20 @@
+open Ctypes
+open Foreign
+
+type mrb = unit ptr
+
+let mrb : mrb typ = ptr void
+let mrb_open = foreign "mrb_open" (void @-> returning mrb)
+let mrb_close = foreign "mrb_close" (mrb @-> returning void)
+
+let mrb_load_string =
+  foreign "mrb_load_string" (mrb @-> string @-> returning void)
+
+let () =
+  let mrb_instance = mrb_open () in
+
+  print_endline "Executing Ruby code from OCaml:";
+  let _ = mrb_load_string mrb_instance "puts 'hello1234'.match?(/hello\\d+/)" in
+
+  mrb_close mrb_instance;
+  print_endline "mruby instance closed successfully."