Use `~W` for general objects, not `~S`

[jpellegrini]

Hi @egallesio !

Error messages do not know what the object is, so they shouldn't assume it's not circular:

(define c (list 1 2 3 4))
(set-cdr! (cdddr c) (cdr c))
(+ c)
  => loops

[jpellegrini]

Maybe this also happens in other files. I just checked number.c...

[jpellegrini]

I have added patches for other files (not all of them)...

But I wonder if it wouldn't make sense to have a single directive, ~S, that would already deal properly with circular structures?

[egallesio]

You are right @jpellegrini,

I should have seen this.

But I wonder if it wouldn't make sense to have a single directive, ~S, that would already deal properly with circular structures?

That would be probably a better solution. We could make ~S and ~W be equivalent in error messages. For errors, the format parsing is done in the specific function print_format in file src/error.c. This should be easier than passing on all files (and when we have an error, the overhead implied by ~W doesn't matter).

[egallesio]

Hi @jpellegrini, I have modified the formatting function for errors. Now, both ~S and ~W use write* to print the culprit in an error message. Thanks for signaling the problem. Since, it should resolve the problem, I close this PR, but you can reopen it, if needed.

[jpellegrini]

Great news! :smile: