cond(itionals) with optional execution of statements
hello, i wrote a little macro (file condx.scm) that allow : cond(itionals) with optional execution of statements before: (define-syntax condx (syntax-rules (exec) ((_) (error 'condx "No else clause")) ((_ (else e ...)) (let () e ...)) ((_ (exec s ...) d1 ...) (let () s ... (condx d1 ...))) ((_ (t e ...) tail ...) (if t (let () e ...) (condx tail ...) use it like that: mattei@macbook-pro-touch-bar library-FunctProg % guile GNU Guile 3.0.7 Copyright (C) 1995-2021 Free Software Foundation, Inc. Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'. This program is free software, and you are welcome to redistribute it under certain conditions; type `,show c' for details. Enter `,help' for help. scheme@(guile-user)> (load "condx.scm") ;;; note: auto-compilation is enabled, set GUILE_AUTO_COMPILE=0 ;;; or pass the --no-auto-compile argument to disable. ;;; compiling /Users/mattei/Dropbox/git/library-FunctProg/condx.scm ;;; compiled /Users/mattei/.cache/guile/ccache/3.0-LE-8-4.5/Users/mattei/Dropbox/git/library-FunctProg/condx.scm.go scheme@(guile-user)> (define x 1) (condx ((= x 7) 'never) (exec (define y 3) (set! x 7)) ((= y 1) 'definitely_not) (exec (set! y 10) (define z 2)) ((= x 7) (+ x y z)) (else 'you_should_not_be_here)) $1 = 19 i share it to have idea about critics or idea to improve it as it will be part of a Scheme extension to scheme language that will include other features have a good day Damien condx.scm Description: Binary data
Re: Trouble creating SRFI-9 Record in C
maybe add
(define (make-foo-x a b) (make-foo a b))
then call make-foo-x (or reverse names)
On 9/10/21 7:27 PM, paul wrote:
Good day guile-users,
I am having a struggle with SRFI-9 records. They look very
convenient, so i'd like to use them in my Guile scripts. However, i'm
not sure how to correctly construct them from C-land. I have
something like the following:
```
(define-record-type
(make-foo a b)
foo?
(a foo-a)
(b foo-b))
```
In Guile land, that works great. Now, i want to create a foo in C and
pass it to a function in the Guile script. I do something like the
following:
```
scm_c_primitive_load("foo.scm");
scm_call_5(scm_variable_ref(scm_c_lookup("make-foo")),
scm_from_utf8_string("blah"),
scm_from_int32(Int32(42)))
```
However, this results in an error:
guile: uncaught exception:
Wrong type to apply: #
I've tried with and without (define-module foo) at the top of the
file, that doesn't seem to make a difference. I've been able to work
around the issue by defining a wrapper (define (foo-prime a b)
(make-foo a b)) and using that in C as shown above, but that feels
ugly. I'm probably missing something obvious, but trawling the
mailing list didn't turn up anything i could understand.
Does anyone see what i'm doing wrong, or can i simply not use SRFI-9
records in this way?
Thanks, 🙌
p.
Re: Trouble creating SRFI-9 Record in C
Hey Matt,
Yeah that was exactly my workaround 🙂 I was wondering whether i could use the
syntax transformer more "directly" from C, or something like that.
Thanks,
paul
> On 11 Sep 2021, at 23:31, Matt Wette wrote:
>
> maybe add
>
> (define (make-foo-x a b) (make-foo a b))
>
> then call make-foo-x (or reverse names)
>
>> On 9/10/21 7:27 PM, paul wrote:
>> Good day guile-users,
>>
>> I am having a struggle with SRFI-9 records. They look very convenient, so
>> i'd like to use them in my Guile scripts. However, i'm not sure how to
>> correctly construct them from C-land. I have something like the following:
>>
>> ```
>> (define-record-type
>> (make-foo a b)
>> foo?
>> (a foo-a)
>> (b foo-b))
>> ```
>>
>> In Guile land, that works great. Now, i want to create a foo in C and pass
>> it to a function in the Guile script. I do something like the following:
>>
>> ```
>> scm_c_primitive_load("foo.scm");
>> scm_call_5(scm_variable_ref(scm_c_lookup("make-foo")),
>> scm_from_utf8_string("blah"),
>> scm_from_int32(Int32(42)))
>> ```
>>
>> However, this results in an error:
>>
>> guile: uncaught exception:
>> Wrong type to apply: #
>>
>> I've tried with and without (define-module foo) at the top of the file, that
>> doesn't seem to make a difference. I've been able to work around the issue
>> by defining a wrapper (define (foo-prime a b) (make-foo a b)) and using that
>> in C as shown above, but that feels ugly. I'm probably missing something
>> obvious, but trawling the mailing list didn't turn up anything i could
>> understand.
>>
>> Does anyone see what i'm doing wrong, or can i simply not use SRFI-9 records
>> in this way?
>>
>> Thanks, 🙌
>> p.
>>
>
>
