Re: [eclipse-users] more questions although there are no replies :(

J. Manuel Velasco wrote:
> 
> // Try  to call the prolog main function defined in prologCode
> post_goal(term(EC_functor("main",4), A,B,C,D, Result));

main/4 has 4 arguments, but you are giving 5: A,B,C,D,Result.


> if (EC_resume() == EC_succeed)
> {
>    // Asingnation error
>    // prologOutput = Result;

My previous mails contained sample code for how to test types
and get return values from the EC_refs.  See also
http://eclipse-clp.org/eclipse/doc/embedding/embroot009.html#toc16


> [eclipse 2]: main(A,B,C,D).
> lists.eco  loaded traceable 0 bytes in 0.00 seconds
> 
> A = A
> B = B
> C = C
> D = D
> 
> 
> Constraints:
> (2) ctr_orient(1, C_255, A_269, B_283, [lm], 1)
> (4) ctr_orient(1, D_1187, C_255, B_283, [lm], 1)
> (5) ctr_orient(3, D_1187, A_269, B_283, [lf, l, lm], 2)
> (9) ctr_orient(5, D_1187, C_255, A_269, [lm, ibl, bl, sb, br], 2)
> Yes (0.01s cpu)
> 
> But from C++ I don't know how to get the result of the CHR execution.

This is not a "result".  A result is when A,B,C,D have values
and there are no more pending constraints.  You have to think
properly what kind of data you want to return to C++ (strings,
numbers, whatever).  Then you compute that data in Eclipse and
instantiate your main goal's output variables to those results.
Then you extract these variable values from the corresponding
EC_refs in C++.

Keep in mind that C++ has no idea about logical variables or
constraints, so deal with these things on the Eclipse side,
and pass only simple data types across the C++/Eclipse boundary.
Some general remarks about Eclipse embedding are here:
http://eclipse-clp.org/eclipse/archive/eclipse-users/0823.html


-- Joachim