Re: Question about how to check a symbol is bound

[felix . winkelmann]

> On 28/06/2023 14:09, felix.winkelmann@bevuta.com wrote:
> >>
> >> (define-object-type bar
> >>     (field-1 name-of-library#foo)
> >>     (field-2 name-of-other-library#some-other-type))
> >>
> >> ...even though calling symbol-value on those symbols at run time works
> >> just fine. It seems that the symbols imported into the environment at
> >> macro expansion time are handled differently in some way.
> >>
> >
> > I guess during expansion identifiers are renamed to some internal gensym
> > and thus not accessible by name (which is the whole point of a hygienic
> > macro system). Could you not register the "foo" type in a expansion time
> > hash table?
>
> Alas, the requirement is that things like "foo" are part of the lexical
> environment - so can be imported from modules, renamed, be hidden inside
> local scopes, all that stuff!
>

I guess some macro wizard will come up with a way to do this.
But I still think that keeping an expansion/compile-time registry and
accessing it using procedure macros (via "strip-syntax"ed identifiers
to drop all renaming artifacts) is a possible solution.


felix