Using a cl_object in Lisp
I am using CFFI with ECL to interface to a C++ library, which has a C++ class with a data member of type 'cl_object'. Simplified, my C++ code is: class LispObject { public: cl_object object; }; extern "C" cl_object getObject(LispObject* lo) { return lo->object; } extern "C" void setObject(LispObject* lo, cl_object clo) { lo->object = clo; } The full code is: https://common-lisp.net/viewvc/clive/trunk/src/extensions/corral/CliveCorral/LispObjectImpl.hpp?revision=149&view=markup#l59 Can I somehow declare the 'cl_object' type for the 'getValue()' and 'setValue()' functions using CFFI 'defcfun' to get and set ECL objects? Is there a technique using the lower-level FFI? I am looking for a way to do this without compiling C code embedded in Lisp, which I am aware ECL can do. Thank you for any ideas! -- Stewart Milberger Kavalogic, Inc.
To clarify, the issue is not with C++, which I am successfully wrapping with C. The actual issue is using the c_object type in Lisp--if it comes back as a CFFI pointer, how can I use it in Lisp as a Lisp object? Is there something like: (ffi:pointer-to-lisp-object ptr) -- Stewart Milberger Kavalogic, Inc. ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ On July 28, 2018 2:46 PM, Stewart M. <sjm-mail@protonmail.com> wrote:
I am using CFFI with ECL to interface to a C++ library, which has a C++ class with a data member of type 'cl_object'. Simplified, my C++ code is:
class LispObject { public: cl_object object; };
extern "C" cl_object getObject(LispObject* lo) { return lo->object; } extern "C" void setObject(LispObject* lo, cl_object clo) { lo->object = clo; }
The full code is:
Can I somehow declare the 'cl_object' type for the 'getValue()' and 'setValue()' functions using CFFI 'defcfun' to get and set ECL objects? Is there a technique using the lower-level FFI? I am looking for a way to do this without compiling C code embedded in Lisp, which I am aware ECL can do.
Thank you for any ideas!
-- Stewart Milberger Kavalogic, Inc.
Hi Stewart, cl_object's are declared as :object type in ECL's ffi, so (ffi:def-function "getObject" ((lo :pointer-void)) :returning :object) (ffi:def-function "setObject" ((lo :pointer-void) (clo :object))) should work. CFFI does not support this as far as i know. Hope that helps, Marius Gerbershagen Am 29.07.2018 um 00:40 schrieb Stewart M.:
To clarify, the issue is not with C++, which I am successfully wrapping with C.
The actual issue is using the c_object type in Lisp--if it comes back as a CFFI pointer, how can I use it in Lisp as a Lisp object? Is there something like:
(ffi:pointer-to-lisp-object ptr)
-- Stewart Milberger Kavalogic, Inc.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ On July 28, 2018 2:46 PM, Stewart M. <sjm-mail@protonmail.com> wrote:
I am using CFFI with ECL to interface to a C++ library, which has a C++ class with a data member of type 'cl_object'. Simplified, my C++ code is:
class LispObject { public: cl_object object; };
extern "C" cl_object getObject(LispObject* lo) { return lo->object; } extern "C" void setObject(LispObject* lo, cl_object clo) { lo->object = clo; }
The full code is:
Can I somehow declare the 'cl_object' type for the 'getValue()' and 'setValue()' functions using CFFI 'defcfun' to get and set ECL objects? Is there a technique using the lower-level FFI? I am looking for a way to do this without compiling C code embedded in Lisp, which I am aware ECL can do.
Thank you for any ideas!
-- Stewart Milberger Kavalogic, Inc.
I found a link to a similar question: https://stackoverflow.com/questions/44494613/embeddable-common-lisp-ecl-load... I was looking for a more direct way. -- Stewart Milberger Kavalogic, Inc.
participants (2)
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Marius Gerbershagen -
Stewart M.