Re: [Caml-list] MetaOCaml error while running generated code that

["Ömer Sinan Ağacan" <omeragacan@gmail.com>]

> The fix that I have mentioned in the previous message seems to
> work. Before the line with Runcode.run in the file r2.ml, add this
> line
>
>   let () = Clflags.recursive_types := true
>
> When compiling the code, you have to add the flag -I +compiler-lib flag to the
> metacocamlc command line.

I just tried this on my program and now it's failing with this error:

  ➜  unlambda git:(master) ✗ ./unlambda_metaocaml programs/Hello.unl -compile
  Fatal error: exception Symtable.Error(_)

Does that look familiar?

Here's the diff of my changes:

  diff --git a/Makefile b/Makefile
  index 31ab193..4340429 100644
  --- a/Makefile
  +++ b/Makefile
  @@ -6,7 +6,7 @@ unlambda_idris: Unlambda.idr
      idris $< -o $@

   unlambda_metaocaml: Syntax.cmo UnlambdaInterp.cmo UnlambdaCont.cmo
Lift.cmo CmdArgs.cmo UnlambdaStaged.cmo UnlambdaCompiler.cmo
UnlambdaMain.ml
  - metaocamlc -rectypes $^ -o $@ -g
  + metaocamlc -rectypes -I +compiler-lib $^ -o $@ -g

   qbf_metaocaml: QBFSyntax.cmo QBFEval.cmo QBFMain.ml
      metaocamlc $^ -o $@ -g
  diff --git a/UnlambdaMain.ml b/UnlambdaMain.ml
  index 6a6f72f..8627283 100644
  --- a/UnlambdaMain.ml
  +++ b/UnlambdaMain.ml
  @@ -122,6 +122,7 @@ let _ =
         end
       end
     else if opts.compile then
  +    let _ = Clflags.recursive_types := true in
       let _ = Runcode.run (UnlambdaCompiler.compile exp_s) (fun x -> x) in
       ()
     else begin

2015-05-10 12:34 GMT-04:00  <oleg@okmij.org>:
>
> I was kind of hoping for a simpler example. So, I wrote one myself. It
> has two files:
>
> the file r1.ml
>   let auto'apply g = g g
>   let fix f = auto'apply (fun x n -> f (auto'apply x) n)
>
> the file r2.ml, first version
>   let c =
>    .<let fact self n = if n = 0 then 1 else n * self (n-1) in R1.fix fact 5>.
>   let r = Runcode.run c
>   let () = Printf.printf "The result is %d\n" r
>
> If we build the executable as
>       metaocamlc  -rectypes r1.ml r2.ml
>
> and run the result, we see the error you have reported:
>
> File "_none_", line 1:
> Error: Unit  imports from R1, which uses recursive types.
>        The compilation flag -rectypes is required
>
> Fatal error: exception Failure("Error type-checking generated code: scope extrusion?")
>
>
> The fix that I have mentioned in the previous message seems to
> work. Before the line with Runcode.run in the file r2.ml, add this
> line
>
>   let () = Clflags.recursive_types := true
>
> When compiling the code, you have to add the flag -I +compiler-lib flag to the
> metacocamlc command line.
>
> The resulting executable runs and prints the expected result.
>
>> I'm not using REPL. I still tried to do this but (Meta)OCaml REPL is so
>> ridiculously bad I couldn't even manage to load all the dependencies of
>> my program...
> I guess the mileage really varies: I do all my OCaml and MetaOCaml
> development using REPL.
>
> Well, MetaOCaml distribution includes the file to link your own REPL.
> I guess one can easily make MetaOCaml-enabled utop (by linking in the
> necessary libraries and the tiny object file that sets up the
> necessary environment and registers the code printers).
>
>