[racket] eval in a module language

[Joop Ringelberg]

Hello all,

I write a program in Racket that I subsequently compile with Bigloo. So I restrict myself to forms and functions known to Bigloo. In order to ease the transition between the two, I've created a module language that recognizes (a subset of) Bigloo module statements. This works well enough: in Racket, the Bigloo modules are converted to plain racket modules and Bigloo recognizes its modules, too.

However, I run into a problem with eval. 

When I use the following sequence in such a module:

(define-namespace-anchor a)

(define ns (namespace-anchor->namespace a))

(eval (x 1) ns)

I get the message:

procedure application: expected procedure, given: #<void>;

The same example would work in a context where racket is used (no error messages).

This is part of the module language file:

(define-syntax-rule (module-begin (module moduleName clause ...) stmt ...)

  (#%module-begin

   clause ...

   stmt ...))

The above three expressions would wind up in the stmt's.

I think that the namespace anchor is not defined in the right phase. However, I don't know how to change that. But maybe I am wrong.

Any suggestions?

Thanks in advance,

Joop Ringelberg

[Matthias Felleisen]

On May 31, 2012, at 3:36 PM, Joop Ringelberg wrote:

>
> (define-namespace-anchor a)
> (define ns (namespace-anchor->namespace a))
> (eval (x 1) ns)
>
> I get the message:
> procedure application: expected procedure, given: #<void>;
>

This is not enough code. What is x? Do you mean '(x 1)? -- Matthias

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[Joop Ringelberg]

Matthias,

I apologise for the incomplete example.

And I apologise, too, for the email: it turns out to be a false alarm.

On stripping my module language file to make a small and complete example I noticed that I had included a syntax-rule for the bigloo module expression keyword "eval" - effectively ignoring it which of course explains what happens.

Thank you.

Joop

On Thu, May 31, 2012 at 11:34 PM, Matthias Felleisen <matt...@ccs.neu.edu> wrote:

On May 31, 2012, at 3:36 PM, Joop Ringelberg wrote:

>
> (define-namespace-anchor a)
> (define ns (namespace-anchor->namespace a))
> (eval (x 1) ns)
>
> I get the message:
> procedure application: expected procedure, given: #<void>;
>

This is not enough code. What is x? Do you mean '(x 1)? -- Matthias

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