Using in C a function defined in guile

Using in C a function defined in guile

[Vladimir Zhbanov]

Hi, guilers.

After speaking with a man who doesn't like scheme and wants to make all
his work in C, I wonder if there is an easy way to make the procedures
wholly written in Guile available in C, besides any kind of 'eval'.
Looking through the guile info I didn't found anything other.

Thanks,
  Vladimir

Re: Using in C a function defined in guile

[Taylan Ulrich Bayırlı/Kammer]

Vladimir Zhbanov <vzhbanov@gmail.com> writes:

> Hi, guilers.
>
> After speaking with a man who doesn't like scheme and wants to make all
> his work in C, I wonder if there is an easy way to make the procedures
> wholly written in Guile available in C, besides any kind of 'eval'.
> Looking through the guile info I didn't found anything other.

You might want to look into the Dynamic FFI section of the Guile Info
manual: (info "(guile) Dynamic FFI")

Web version:
http://www.gnu.org/software/guile/manual/html_node/Dynamic-FFI.html

In summary, you can get pointers to Guile procedures via
'procedure->pointer' ('scm_procedure_to_pointer' in the C API).

Working with complicated struct types might be somewhat uncomfortable,
and I'm working on https://github.com/taylanub/scheme-bytestructures to
solve that, but I haven't worked on integrating it with the FFI much
yet.  On the meanwhile there's (info "(guile) Foreign Structs").

Web:
http://www.gnu.org/software/guile/manual/html_node/Foreign-Structs.html

You might also want to go through the rest of the FFI chapter of the
manual to see if there's anything useful for you:
(info "(guile) Foreign Function Interface")

Web:
http://www.gnu.org/software/guile/manual/html_node/Foreign-Function-Interface.html

> Thanks,
>   Vladimir

That's my limited knowledge.
Hope it helps,
Taylan

Re: Using in C a function defined in guile

[Panicz Maciej Godek]

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2015-09-06 16:10 GMT+02:00 Vladimir Zhbanov <vzhbanov@gmail.com>:

> Hi, guilers.
>
> After speaking with a man who doesn't like scheme and wants to make all
> his work in C, I wonder if there is an easy way to make the procedures
> wholly written in Guile available in C, besides any kind of 'eval'.
> Looking through the guile info I didn't found anything other


This is because this is contrary to the intended use of Guile (which
focuses on having C procedures available in Scheme rather than other way
around).

I think that you may take a look at something that compiles Scheme code to
C, like Gambit, Chicken, Scheme->C or Stalin.

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Re: Using in C a function defined in guile

[Vladimir Zhbanov]

On Sun, Sep 06, 2015 at 05:23:38PM +0200, Panicz Maciej Godek wrote:
> 2015-09-06 16:10 GMT+02:00 Vladimir Zhbanov <vzhbanov@gmail.com>:
> 
> > Hi, guilers.
> >
> > After speaking with a man who doesn't like scheme and wants to make all
> > his work in C, I wonder if there is an easy way to make the procedures
> > wholly written in Guile available in C, besides any kind of 'eval'.
> > Looking through the guile info I didn't found anything other
> 
> 
> This is because this is contrary to the intended use of Guile (which
> focuses on having C procedures available in Scheme rather than other way
> around).
> 
> I think that you may take a look at something that compiles Scheme code to
> C, like Gambit, Chicken, Scheme->C or Stalin.

Sorry, I won't use them, the project in question is gEDA and (I hope) it
hardly will use any other Scheme dialect in the near future.

Thanks,
  Vladimir

Re: Using in C a function defined in guile

[Mike Gran]

On Sunday, September 6, 2015 7:10 AM, Vladimir Zhbanov <vzhbanov@gmail.com> wrote:


>
>
>Hi, guilers.
>
>After speaking with a man who doesn't like scheme and wants to make all
>his work in C, I wonder if there is an easy way to make the procedures
>wholly written in Guile available in C, besides any kind of 'eval'.
>Looking through the guile info I didn't found anything other.

The simplest way to implement such a thing is using
functions like scm_c_eval_string, where one creates a string
containing Guile code and executes it.

There are more complicated strategies that might be slightly faster.
One could get a variable that contains a procedure by using
scm_c_public_lookup.  Then, the procedure itself can be extracted
by using scm_variable_ref.  And it can be called using
The scm_call_0, scm_call_1 family of functions.

There is an example in the manual here
http://www.gnu.org/software/guile/manual/html_node/Accessing-Modules-from-C.html

-Mike

Re: Using in C a function defined in guile

[Arne Babenhauserheide]

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Am Sonntag, 6. September 2015, 16:09:06 schrieb Mike Gran:
> The simplest way to implement such a thing is using
> functions like scm_c_eval_string, where one creates a string
> containing Guile code and executes it.
> …
> There is an example in the manual here
> http://www.gnu.org/software/guile/manual/html_node/Accessing-Modules-from-C.html

That’s much better than what I wrote. Please don’t let yourself get stuck on my mail.

Best wishes,
Arne

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Re: Using in C a function defined in guile

[Vladimir Zhbanov]

Mike, thank you!

It seems to be the info I searched for.

Thanks,
  Vladimir

Re: Using in C a function defined in guile

[Arne Babenhauserheide]

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Hi Vadimir,

Am Sonntag, 6. September 2015, 17:10:01 schrieb Vladimir Zhbanov:
> After speaking with a man who doesn't like scheme and wants to make all
> his work in C, I wonder if there is an easy way to make the procedures
> wholly written in Guile available in C, besides any kind of 'eval'.
> Looking through the guile info I didn't found anything other.

The manual shows how to call Guile functions from your program:
http://www.gnu.org/software/guile/manual/guile.html#Guile-Initialization-Functions

The sample however embeds a full Guile shell:
http://www.gnu.org/software/guile/manual/guile.html#A-Sample-Guile-Main-Program

If I recall correctly, if you only want to provide the Scheme
functions, stick to scm_init_guile and scm_with_guile.

See Initializing Guile from the API reference:
http://www.gnu.org/software/guile/manual/guile.html#Initialization

Best wishes,
Arne

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Re: Using in C a function defined in guile

[Vladimir Zhbanov]

On Sun, Sep 06, 2015 at 06:21:35PM +0200, Arne Babenhauserheide wrote:
> Hi Vadimir,
> 
> Am Sonntag, 6. September 2015, 17:10:01 schrieb Vladimir Zhbanov:
> > After speaking with a man who doesn't like scheme and wants to make all
> > his work in C, I wonder if there is an easy way to make the procedures
> > wholly written in Guile available in C, besides any kind of 'eval'.
> > Looking through the guile info I didn't found anything other.
> 
> The manual shows how to call Guile functions from your program:
> http://www.gnu.org/software/guile/manual/guile.html#Guile-Initialization-Functions
> 
> The sample however embeds a full Guile shell:
> http://www.gnu.org/software/guile/manual/guile.html#A-Sample-Guile-Main-Program
> 
> If I recall correctly, if you only want to provide the Scheme
> functions, stick to scm_init_guile and scm_with_guile.
> 
> See Initializing Guile from the API reference:
> http://www.gnu.org/software/guile/manual/guile.html#Initialization

Thank you, Arne.

I've already read all the sections you're referring to here.

Cheers,
  Vladimir

Re: Using in C a function defined in guile

[David Kastrup]

Vladimir Zhbanov <vzhbanov@gmail.com> writes:

> Hi, guilers.
>
> After speaking with a man who doesn't like scheme and wants to make all
> his work in C, I wonder if there is an easy way to make the procedures
> wholly written in Guile available in C, besides any kind of 'eval'.
> Looking through the guile info I didn't found anything other.

C++ allows for some syntactically nicer techniques.

Cf
<URL:http://git.savannah.gnu.org/cgit/lilypond.git/commit/?id=652f454fae6ed31ced7f9c3ce22dbc5752460a8c>
for an implementation in a large-scale C++/GUILE project.  The
interesting files are those created from scratch in the patch (green in
the diffstat).

-- 
David Kastrup