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* #:printer filed in language specification.
@ 2021-09-17 22:50 Justin Veilleux
  2021-09-18 14:47 ` Maxime Devos
  0 siblings, 1 reply; 6+ messages in thread
From: Justin Veilleux @ 2021-09-17 22:50 UTC (permalink / raw)
  To: guile-user

Hello, everyone.

To familiarize myself with guile's compiler tower, I implemented a 
lambda calculus interpreter using guile.

It works relatively well. However, I also wanted it to print a human 
readable version of the procedures created. (It is hard to tell whether 
#<procedure 1e39a38 (s)> is a correct church encoding of the number 3) 
With a lot of fiddling, I managed to write a function that turns a 
procedure into an S-expression.

However, when I tell guile to use it as a pretty printer using the 
#:printer keyword, the repl doesn't actually use it. What can I do to 
fix this ?





^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: #:printer filed in language specification.
  2021-09-17 22:50 #:printer filed in language specification Justin Veilleux
@ 2021-09-18 14:47 ` Maxime Devos
  2021-09-18 15:24   ` Justin Veilleux
  2021-09-19 12:11   ` Zelphir Kaltstahl
  0 siblings, 2 replies; 6+ messages in thread
From: Maxime Devos @ 2021-09-18 14:47 UTC (permalink / raw)
  To: Justin Veilleux, guile-user

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Justin Veilleux schreef op vr 17-09-2021 om 18:50 [-0400]:
> It works relatively well. However, I also wanted it to print a human 
> readable version of the procedures created. (It is hard to tell whether 
> #<procedure 1e39a38 (s)> is a correct church encoding of the number 3) 
> With a lot of fiddling, I managed to write a function that turns a 
> procedure into an S-expression.

The #:printer is only used by things like "guild compile -o ..." I think.

One option is to create ‘applicable structs’ (unfortunately they aren't
documented), setting the procedure to the actual procedure, and the record
printer (set-record-type-printer!) to something printing the S-exp of the
applicable struct.

Greetings,
Maxime

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: #:printer filed in language specification.
  2021-09-18 14:47 ` Maxime Devos
@ 2021-09-18 15:24   ` Justin Veilleux
  2021-09-19 12:11   ` Zelphir Kaltstahl
  1 sibling, 0 replies; 6+ messages in thread
From: Justin Veilleux @ 2021-09-18 15:24 UTC (permalink / raw)
  To: Maxime Devos, guile-user

Thanks a lot.

On September 18, 2021 10:47:56 a.m. EDT, Maxime Devos <maximedevos@telenet.be> wrote:
>Justin Veilleux schreef op vr 17-09-2021 om 18:50 [-0400]:
>> It works relatively well. However, I also wanted it to print a human 
>> readable version of the procedures created. (It is hard to tell whether 
>> #<procedure 1e39a38 (s)> is a correct church encoding of the number 3) 
>> With a lot of fiddling, I managed to write a function that turns a 
>> procedure into an S-expression.
>
>The #:printer is only used by things like "guild compile -o ..." I think.
>
>One option is to create ‘applicable structs’ (unfortunately they aren't
>documented), setting the procedure to the actual procedure, and the record
>printer (set-record-type-printer!) to something printing the S-exp of the
>applicable struct.
>
>Greetings,
>Maxime


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: #:printer filed in language specification.
  2021-09-18 14:47 ` Maxime Devos
  2021-09-18 15:24   ` Justin Veilleux
@ 2021-09-19 12:11   ` Zelphir Kaltstahl
  2021-09-19 12:24     ` Maxime Devos
  1 sibling, 1 reply; 6+ messages in thread
From: Zelphir Kaltstahl @ 2021-09-19 12:11 UTC (permalink / raw)
  To: Maxime Devos; +Cc: Guile User

Hi Maxim!

Do you know of any simple example anywhere for applicable structs? I might have
another use for them.

Regards,
Zelphir

On 9/18/21 4:47 PM, Maxime Devos wrote:
> Justin Veilleux schreef op vr 17-09-2021 om 18:50 [-0400]:
>> It works relatively well. However, I also wanted it to print a human 
>> readable version of the procedures created. (It is hard to tell whether 
>> #<procedure 1e39a38 (s)> is a correct church encoding of the number 3) 
>> With a lot of fiddling, I managed to write a function that turns a 
>> procedure into an S-expression.
> The #:printer is only used by things like "guild compile -o ..." I think.
>
> One option is to create ‘applicable structs’ (unfortunately they aren't
> documented), setting the procedure to the actual procedure, and the record
> printer (set-record-type-printer!) to something printing the S-exp of the
> applicable struct.
>
> Greetings,
> Maxime

-- 
repositories: https://notabug.org/ZelphirKaltstahl




^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: #:printer filed in language specification.
  2021-09-19 12:11   ` Zelphir Kaltstahl
@ 2021-09-19 12:24     ` Maxime Devos
  2021-09-20  8:04       ` Zelphir Kaltstahl
  0 siblings, 1 reply; 6+ messages in thread
From: Maxime Devos @ 2021-09-19 12:24 UTC (permalink / raw)
  To: Zelphir Kaltstahl; +Cc: Guile User

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Zelphir Kaltstahl schreef op zo 19-09-2021 om 12:11 [+0000]:
> Hi Maxim!
> 
> Do you know of any simple example anywhere for applicable structs? I might have
> another use for them.

From NEWS in the Guile source code:

  ** Applicable struct support

  One may now make structs from Scheme that may be applied as procedures.
  To do so, make a struct whose vtable is `<applicable-struct-vtable>'.
  That struct will be the vtable of your applicable structs; instances of
  that new struct are assumed to have the procedure in their first slot.
  `<applicable-struct-vtable>' is like Common Lisp's
  `funcallable-standard-class'. Likewise there is
  `<applicable-struct-with-setter-vtable>', which looks for the setter in
  the second slot. This needs to be better documented.

For a not-very-simple example, see modules/oop/gooops.scm in Guile's source code.
I don't know any simple examples.

Greetings,
Maxime.

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: #:printer filed in language specification.
  2021-09-19 12:24     ` Maxime Devos
@ 2021-09-20  8:04       ` Zelphir Kaltstahl
  0 siblings, 0 replies; 6+ messages in thread
From: Zelphir Kaltstahl @ 2021-09-20  8:04 UTC (permalink / raw)
  To: Maxime Devos; +Cc: Guile User

Hi Maxim!

Thank you for your reply!

I do not know how to create such a vtable, what it means to have a vtalbe which
is `<applicable-struct-vtable>` or how to set it for a struct, but I should have
a look at the manual and see, what comes up when searching for vtable.

Regards,
Zelphir

On 9/19/21 2:24 PM, Maxime Devos wrote:
> Zelphir Kaltstahl schreef op zo 19-09-2021 om 12:11 [+0000]:
>> Hi Maxim!
>>
>> Do you know of any simple example anywhere for applicable structs? I might have
>> another use for them.
> From NEWS in the Guile source code:
>
>   ** Applicable struct support
>
>   One may now make structs from Scheme that may be applied as procedures.
>   To do so, make a struct whose vtable is `<applicable-struct-vtable>'.
>   That struct will be the vtable of your applicable structs; instances of
>   that new struct are assumed to have the procedure in their first slot.
>   `<applicable-struct-vtable>' is like Common Lisp's
>   `funcallable-standard-class'. Likewise there is
>   `<applicable-struct-with-setter-vtable>', which looks for the setter in
>   the second slot. This needs to be better documented.
>
> For a not-very-simple example, see modules/oop/gooops.scm in Guile's source code.
> I don't know any simple examples.
>
> Greetings,
> Maxime.

-- 
repositories: https://notabug.org/ZelphirKaltstahl




^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2021-09-20  8:04 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-17 22:50 #:printer filed in language specification Justin Veilleux
2021-09-18 14:47 ` Maxime Devos
2021-09-18 15:24   ` Justin Veilleux
2021-09-19 12:11   ` Zelphir Kaltstahl
2021-09-19 12:24     ` Maxime Devos
2021-09-20  8:04       ` Zelphir Kaltstahl

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