bug#52112: Compilation of macro returning record type fails

bug#52112: Compilation of macro returning record type fails

[Jean Abou Samra]

Record types are self-evaluating:

scheme@(guile-user)> (eval (make-record-type 'my-record '()) 
(current-module))
$1 = #<record-type my-record>

Yet, when a macro returns a record type, Guile fails
to byte-compile the code, even though the execution
(via the evaluator) works fine. Here is a simple example:


(define-macro (my-macro)
   (make-record-type 'my-record-2 '()))

(display (my-macro))
(newline)


Execution log:


$ guile --no-auto-compile test.scm
#<record-type my-record-2>

$ guile test.scm
;;; note: auto-compilation is enabled, set GUILE_AUTO_COMPILE=0
;;;       or pass the --no-auto-compile argument to disable.
;;; compiling /home/jean/test.scm
;;; WARNING: compilation of /home/jean/test.scm failed:
;;; unhandled constant #<record-type my-record-2>
#<record-type my-record-2>

This is with Guile version 3.0.5.130-5a1e7.

bug#52112: Compilation of macro returning record type fails

[Taylan Kammer]

On 25.11.2021 18:45, Jean Abou Samra wrote:
> Record types are self-evaluating:
> 
> scheme@(guile-user)> (eval (make-record-type 'my-record '()) (current-module))
> $1 = #<record-type my-record>
> 
> Yet, when a macro returns a record type, Guile fails
> to byte-compile the code, even though the execution
> (via the evaluator) works fine. Here is a simple example:
> 
> 
> (define-macro (my-macro)
>   (make-record-type 'my-record-2 '()))
> 
> (display (my-macro))
> (newline)
> 
> 
> Execution log:
> 
> 
> $ guile --no-auto-compile test.scm
> #<record-type my-record-2>
> 
> $ guile test.scm
> ;;; note: auto-compilation is enabled, set GUILE_AUTO_COMPILE=0
> ;;;       or pass the --no-auto-compile argument to disable.
> ;;; compiling /home/jean/test.scm
> ;;; WARNING: compilation of /home/jean/test.scm failed:
> ;;; unhandled constant #<record-type my-record-2>
> #<record-type my-record-2>
> 
> This is with Guile version 3.0.5.130-5a1e7.

I don't think that's supposed to work.  I find it surprising that
record-type objects are self-evaluating, and in any case they can't
be turned into bytecode.

Your macro could return code that evaluates to a record definition.
Would that solve your use-case?

-- 
Taylan

bug#52112: Compilation of macro returning record type fails

[Jean Abou Samra]

Thanks for your reply.

Le 26/11/2021 à 19:54, Taylan Kammer a écrit :
> I don't think that's supposed to work.  I find it surprising that
> record-type objects are self-evaluating, and in any case they can't
> be turned into bytecode.
>
> Your macro could return code that evaluates to a record definition.
> Would that solve your use-case?


Yes, that is how I solved it in LilyPond
(https://gitlab.com/lilypond/lilypond/-/merge_requests/1026).

I was also somewhat surprised to see that
record types are self-evaluating. I don't
know where to check in R6RS what the expected
behavior would be. At any rate, it seems that
there is an inconsistency between the interpreter
and the compiler that would warrant resolving
either way.