Re: Multiple environments

Hi!
Theoretically, the way is
  *(load "module.so" local-eval)*
where is
*(define local-eval (let ((e (scheme-report-environment 5 #t))) (lambda
(sexp) (eval sexp e)))))*

In reality the chicken version  of (scheme-report-environment version
[mutable])
does not take the second parameter (mutable #t),
how it say  'scheme module' docs
https://wiki.call-cc.org/man/5/Module%20scheme#eval

Error: bad argument count - received 2 but expected 1: #<procedure
(scheme#scheme-report-environment n)>

So I think not just global vars but dynamic parameters and form
(parametrize...) the only way
https://wiki.call-cc.org/man/5/Module%20(chicken%20base)#parameters
or I'm wrong.


вс, 16 июн. 2024 г. в 12:27, <[email protected]>:

> > I’m looking for an elegant way how to manage multiple environments
> (global bindings) to build a concurrency simulator. The input of my
> simulator is the number of actors/coroutines/etc. I would like to have
> fully separate environments for these coroutines, so they can mutate
> variables with same name and won’t affect each other. The communication
> between each actor is not done via shared variables.
> >
> > [...]
> >
> > I know I could use variables in the lambda scope, but I would prefer to
> avoid restricting the actors implementation.
> >
> > I have a prototype in Racket, where I use make-base-namespace to create
> namespaces for each actor. I can then call eval with the lambda as first
> argument and the mutable namespace as second.
> >
> > Would somebody in the mailing list have a suggestion how to handle this
> in an elegant way in CHICKEN?
>
> Hi!
>
> You can use modules in combination with "eval" to isolate global
> environments.
> First you create a module at runtime using via "(eval '(module ...))" and
> then
> evaluate an expression in the context of the module by using
> "module-environment",
> passing this env as a second argument to eval. This has several
> restrictions,
> though, so it is not equivalent to the way your Racket implementation
> works.
>
> Also you probably want to compile your code instead of evaluation code at
> runtime. Would it be possible to use a different syntax for global variable
> accesses (both read and write, so something like "get" and "put"
> operations)?
> That would make the implementation much easier and also has the benefit of
> making global accesses more obvious to the one reading the code and it also
> helps to make the code more portable to other Scheme implementations.
>
> Is the set of globals fixed or can an actor extend this set? Do you want to
> compile your code (I assume you do)? Do you want these globals to be fully
> equivalent to normal global bindings?
>
>
> felix
>
>
>