[CM] SDL is unchanged still but here's another for ImGui

[chohag at jtan.com]

Norman Gray writes:
> 
> Matthew, hello.
>
> On 7 Jul 2024, at 20:32, chohag at jtan.com wrote:
>
> > On the other hand in both cases what's left is mostly writing the
> > S7 interface functions which for the most part should require only
> > naming the constant or function. Anyone like writing long lists of
> > repetetive code?
>
> Writing no; generating... sometimes.

Indeed consider that tongue in cheek. I expect (hope!) by the end
there'll be a higher ratio of generated:written code. At this early
stage I'm more concerned with feeling out how the API will be
exported and a little bit of repetition isn't a huge problem yet.

There's also still a few features of S7 I'm not taking advantage
of yet like function signatures and I wouldn't like to have to
inject them into tangled up macros.

> Faced with a similar problem, I've used s7 to generate C before.  Specifically, I can point towards util-extra.c.in at [1], which includes #(...) forms within the source, which expand to C, using a very simple function in scheme-macro-filter.scm there.

Thanks I'll take a look. I tend to lean toward CPP macros through
familiarity but that may change as I build up a body of code, provided
I can keep magic out of the build process.

> I take the opportunity to mention this, partly to join in very late on a snd/s7 list thread of a month or so ago, expressing communal enthusiasm for s7 (thread 's7 got some love in the Lisp game jam').  The program I'm pointing to does a lot of its
> work in s7, although (in the terms of the blogpost which started that thread) I can't tell if it uses the 'icing' or 'cake' model: C calls s7 main calls C calls s7.  The point of this paragraph is to log that I've become more and more of an s7 fan,
> in the sense that it seems to have exactly the right tone to match the extension problem very well.  So thanks, Bill.

This is essentially why I've settled on S7. There's no "FFI" as
such, instead I can flit back and forth between S7 and C seamlessly
as needed. I guess that makes S7 the ... fork?

Matthew