Re: About adding new egg "varg"

[Mario Domenech Goulart via Chicken-users]

Hi,

On Sat, 6 Dec 2025 16:43:28 + li lu  wrote:

> Yes it was similar to DSSSL,
> but I think there are some differences between DSSSL and *varg*:
>
> - DSSSL define that parameters should keep particular type order:
>   - required parameter(similar to `#:literal` in *varg*)
>   - `#!optional` parameter(similar to `#:without-value` in *varg*)
>   - `#!rest` parameter(similar to `#:literal` when set `#:enable-unknown` in 
> *varg*)
>   - `#!key` parameter(similar to `#:with-value` in *varg*)
>
>   *varg* does not require parameters are in particular order,
>   they are parsed by matching keywords between procedure
>   definition and procedure call
>
> - DSSSL set `#!optional` parameters to `#f` if
>   they are not bind to a default value and not presented in function call.
>   Usually I hope it can be explicit set or not, but not `#f` or others.
>
> - In DSSSL, usually `#!optional` parameters cannot show its meaning in
>   procedure calling, I have to move to procedure definition to get it.
>   In *varg*, by defining meaningful keyword,
>   I can know what this parameter is at the calling place,
>   without searching other code
>
> Those are what I try to improve about parameter parsing in *varg*

Fair enough.  Thanks for elaborating on the differences between varg and
DSSSL.  I was mostly checking whether you were aware of the support for
DSSSL (which you are).

Your egg has been added to CHICKEN 5 and CHICKEN 6.  Thanks.

All the best.
Mario
-- 
https://parenteses.org/mario

Re: About adding new egg "varg"

[siiky via Chicken-users]

Hi,

> Actually the required egg /varg/ was extracted from another project 
> https://github.com/riku-ri/libyaml.ss  libyaml.ss>. And libyaml.ss build the C/C++ source by chicken- 
> install using gcc/clang options. I’m not sure if win32/MinGW also 
> work. Anyway you’re right, /varg.ss/ actually did not require the 
> platform specified functions. So I remove it in the new commit(did 
> not release yet)

Makes sense.

> I added another example including how to get values and print them
> The new example is a little bit log so did not show it here

Thanks, that makes it a bit clearer.

> Personally I preffered |cond| than other condition syntax, because 
> it can add multiple steps in a branch, without wrapping additional | 
> let| or |begin|

Actually that's also a plus of `when`/`unless`:

(when (= ans 42)
  (do-thing)
  (do-other-thing))

But as I said, it's a matter of style.

siiky

Re: About adding new egg "varg"

[Mario Domenech Goulart via Chicken-users]

Hi,

On Sat, 6 Dec 2025 05:27:26 + li lu via Chicken-users 
 wrote:

> Thanks for advice, there are some explanation about the confusion:
>
> * About the platform
>
> * Actually the required egg varg was extracted from another project 
> https://github.com/riku-ri/libyaml.ss. And
>  libyaml.ss build the C/C++ source by chicken-install using gcc/clang 
> options. I’m not sure if win32/MinGW also work.
>  Anyway you’re right, varg.ss actually did not require the platform specified 
> functions. So I remove it in the new
>  commit(did not release yet)
>
> * About the usage
>
> * I added another example including how to get values and print them
>  The new example is a little bit log so did not show it here
>
> * https://github.com/riku-ri/varg.ss/blob/main/docs/usage.md#examples
> * https://riku-ri.github.io/varg.ss/docs/usage.html#examples
>
> * About the condition syntax
>
> * Personally I preffered cond than other condition syntax, because it can add 
> multiple steps in a branch, without
>  wrapping additional let or begin
>
> Hope that these can clarify your confusion.

Thanks for sharing your code and for the clarifications.

Just to make sure we are not adding something that already exists
natively in CHICKEN in a slightly different form: CHICKEN supports
extended DSSSL style parameter lists, which seem to provide a similar
functionality.  It's not standard Scheme and is bit hidden in the
manual: https://wiki.call-cc.org/man/5/Module%20scheme#procedures
(scroll a bit down or look for "As an extension to R5RS, CHICKEN also
supports "extended" DSSSL style parameter lists").

Using the cp case as an example:

(define (cp from to #!key mode force)
  (pp `((force ,force) (mode ,mode) (from ,from) (to ,to

(cp "tmp/a" "tmp/b")
;; => ((force #f) (mode #f) (from "tmp/a") (to "tmp/b"))

(cp "tmp/a" "tmp/b" force: #t)
;; => ((force #t) (mode #f) (from "tmp/a") (to "tmp/b"))

(cp "tmp/a" "tmp/b" force: #t mode: #o777)
;; => ((force #t) (mode 511) (from "tmp/a") (to "tmp/b"))

(cp "tmp/a" "tmp/b" mode: #o777)
;; => ((force #f) (mode 511) (from "tmp/a") (to "tmp/b"))

All the best.
Mario
-- 
https://parenteses.org/mario

About adding new egg "varg"

[li lu via Chicken-users]

Hi all,

I made a egg about parsing procedure parameters, release-info URI is:
- 
https://github.com/riku-ri/varg.ss/releases/latest/download/varg.ss.release-inf

Hope that it can be add to online location

Thanks