Re: [Chicken-hackers] simplifying loading/linking/import (long)

[Felix Winkelmann]

> The obvious reason would be a failure to compile with -j or -J.  It's
> probably surprising to newbies that it's not enough to write (module foo
> ...) in a file "foo.scm" and then say "(use foo)" at the REPL; you have
> to compile "foo.scm" with -J at the very least.

That's true. The "obvious" solution (to load the .so and "import" the
module bindings) is only obvious to those who understand the
underlying implementation.

> 
>> 
>> * libchicken contains a number of entry-points, one for each library
>>   unit that comes with the core system. The registry must already have
>>   entries for these. Users might want to have to use a similar
>>   physical structure of their code, so we will have to provide means
>>   to add "default" registry entries, I think (I'm not completely
>>   sure right now - the resolution of the entry-points happens
>>   automatically by the linker, but we have to make later "import"s
>>   aware of this.)
> 
> IMO this should be a special case for libchicken.  I see no reason why
> ordinary users should bundle multiple modules into a single .so file.

It must be possible, though. There must at least be some low-level
operation available. 

> 
>> * Currently "(declare (unit ...))" calls the entry-point,
>>   _initializing_ the compilation unit. Later "import"s will just
>>   incorporate the bindings. Do we want to initialize the compilation
>>   unit on the first "import"? If yes, we need to separate the notions
>>   of declaring an externally available entry-point and calling it, the
>>   latter being done (we hope) transparently by "import".
> 
> Well, that is what `use` already does, no?

"use" only does that the first time a dynamically loadable extension
is loaded. Static entry-points (declared via "(declare (unit ...))")
are called at the start of the toplevel code of the current
compilation unit, before everything else (specifically, it produces a
"##core#callunit" special form, inserted before the actual user code.


felix