Re: Using C-Predicates in Eclipse

Georg Fette wrote:
> 
> Hiho,
> I have now managed to link my external C++-function to a eclipse-function,
> but when I call it in eclipse it simply crashes with a windows-"bad memory
> reference error" and my eclipse-ide is closed. When I made some tests with
> my C++-function I found out, that the crash happens, when the
> input-parameter is unified. This is my code:
> 
> #include <eclipseclass.h>
> 
> extern "C" __declspec(dllexport) int p_test() {
>     char *myString;
> 
>     ec_get_string(ec_arg(1), &myString);
>     return EC_succeed;
> }
> 
> Do I use the ec_get_string-function in a wrong way ?
> Thx for answers.
> 
> Georg


You need to use the C++ interface functions/methods.
See "Embedding and Interfacing Manual"
Appendix "Summary of C++ Interface Functions"
"Decomposing ECLiPSe terms in C++"

EC_word EC_arg(int i) 
     returns the i'th argument of the predicate call. 

int EC_word::is_string(char **) 

     checks whether the EC_word is a string (or atom) and converts
     it to a C++ string. This string is volatile, ie. it should be
     copied when it is required to survive resuming of ECLiPSe. 

int EC_word::is_string(char **, long *) 

     checks whether the EC_word is a string (or atom) and converts
     it to a C++ string. This string is volatile, ie. it should be
     copied when it is required to survive resuming of ECLiPSe. The
     string's length is returned in the second argument. 



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 Joachim Schimpf              /             phone: +44 20 7594 8187
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