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niedz., 20 lis 2022 o 23:41 Per Bothner <per@bothner.com> napisał(a):
>
>
> On 11/19/22 06:37, Panicz Maciej Godek via Kawa wrote:
> > When I try to use this code from yet another module -- more specifically,
> > this one:
> >
> >
> https://github.com/panicz/grasp-android/blob/master/stages/retreat/GRASP/src/panel.scm#L130
> >
> > as
> >
> > (define-mapping (on-key-press code) never)
> >
> > I get the error message
> >
> > define-constant is only allowed in a <body>
> >
> > but when I use the expanded version
> >
> > (define on-key-press (mapping (code) never))
> >
> > everything works.
> >
> > I wonder what could be the reason of Kawa's behavior.
>
> Kawa is presumably complaining that the define-early-constant is
> in a non-<body> context.
>
> This is allowed:
> (begin (define-early-constant ...) ...)
>
> This is not:
> (list (define-early-constant ...) ...)
>
> One of the problems with Scheme S-expression-based syntax is that
> it is sometimes tricky to tell what parenthesis does what.
> For example, it is easy to end up with this after some macro-expansion:
>
> ((define-early-constant ...))
>
>
I understand this message the way you explained it
-- it just doesn't make sense in my context.
There seems to be an issue with module dependency resolution.
The problematic expansion was in the (panel) module.
It contains a dependency on the (mapping) module.
The main module (either grasp-terminal.scm or grasp-desktop.scm)
included (import (panel)), and the compilation failed with the above
message.
But when I add (import (mapping)) to the main module -- before the
(import (panel)) clause -- the compilation succeeds. (However, if I add it
after (import (panel)) -- it still breaks).
I realized that I ran into that problem early on during my work,
but instead of reporting it, I just started including module dependencies
transitively in the "right order". This is a workaround, but I think
that there might be some issue between reflection, macro expansion
and module dependency loading.
I'll let you know if I manage to find a minimal set of modules which break
in this way.