Sig,
I wonder whether that should be on by default. I have had some real
frustrations with FFI of late, and something like this might have avoided the
problem. Unless it is easily discoverable, off is almost the same as
non-existent.
Any rumblings on Spock? It would be nice to have even a facade that unifies
the FFI/NB/Alien on all platforms. It would indelicate to mention that this
was supposed to happen in January<g>. I never really expected to see it that
soon, given the problems I had going from 1.1.1 to 1.3 with FFI, and my
rotating errors with Alien callbacks. I changed a bunch of FFI calls (in ways
that I genuinely think should not have been necessary) and retreated to C
functions for GSL callbacks. The latter is frustrating, BAD for my eventually
being able to release a GSL binding (make that REALLY BAD), but not all bad
because C++ is a better formula translator that Smalltalk, and the number
crunching runs at native speeds.
I think these things *can* work - they just don't at present, and the
FFI/NB/Alien split makes it hard to know what to try.
Bill
________________________________________
From: pharo-project-boun...@lists.gforge.inria.fr
[pharo-project-boun...@lists.gforge.inria.fr] on behalf of Igor Stasenko
[siguc...@gmail.com]
Sent: Friday, April 20, 2012 10:46 AM
To: Pharo-project@lists.gforge.inria.fr
Subject: Re: [Pharo-project] [NativeBoost] Generic failure errors when using
nil for void* and char* arguments
On 20 April 2012 15:59, Jan van de Sandt <jvdsa...@gmail.com> wrote:
> Hello,
>
> I use NativeBoost to call some icu4c functions. This works fine most of the
> time. But now I run into the problem that when I pass nil as the argument
> value for one or more void* / char* parameters I get an error. When I pass a
> value or an empty ByteArray than it works.
>
> According to the icu4c documentation I should be able to pass NULL as an
> argument value.
>
> What am I missing?
>
For pointers, there is an options in callouts, #optCoerceNilToNull
which should be set,
then you can invoke the call with nil as argument, which will convert
it to C NULL.
By default this option is OFF, because extra check means extra cycles.
You can control a callout options by either per function call (see
NBBasicExamples>>readDoubleFrom:)
or for all methods of your class as a whole, like:
MyClass class>>ffiCalloutOptions
"by default, return all pointers as an instance of external address "
^ #(
+ optReturnPtrAsExternalAddress
+ optCoerceNilToNull "passing nil as pointer, will convert it
to null(0) "
)
> Jan.
--
Best regards,
Igor Stasenko.
