[Chicken-users] C_alloc OK before C_invoke? (was Re: Constructing parameter lists in C)

[Daniel B. Faken]

On Thu, 21 Jul 2005, Daniel B. Faken wrote:
>
[....]
> 
> Now a preferable solution would be to construct the parameter list,
> as a C_word (scheme-object) via C_list(...), and either
> * use C_callback(scmfn, arglist) for callbacks or
> * use a single entry-point 'scm_applyfn' that takes two
>   scheme-object args and just calls (apply scmfn arglist).

On a related note: is it OK to call C_alloc() to construct data to be 
passed via CHICKEN_invoke()?
  The manual entry for C_alloc() says "..Note that stack-allocated data 
objects have to be passed to Scheme callback functions... This is really 
only usable for callback procedure invokations, make sure not to use it in 
normal code..."
  - but I'm not sure if the point is to not re-use C_alloc() memory or if 
this really means 'only proper callbacks' i.e. after entering scheme.

The C_parameter type taken by CHICKEN_invoke() has a C_word/scheme-object 
field, which would seem to indicate there is some way to pass general 
scheme-objects..
  If NOT with C_alloc(), then how would one construct a non-immediate 
object? (e.g. where would the first arg to C_list() come from?)

  Thanks again!

cheers,
Daniel