Re: [Yap-users] compiling projects

[Vitor S. C. <vi...@bi...>]

Hi Erick,

>=20
> I have both prolog code and external predicates written in C++.
>=20

ok.

> I would like to know if there is a way to produce one single executable
> file with yap 4.3.19. Otherwise, could someone tell me a convenient way
> to compile my project?
>=20

Yap is compiled as follows: first we create a libYap.a library with
the files in the C directory. Then we link this library with the
console/yap.c file. yap.c sets up the system and then calls the
top-level.

To change the top-level you likely want to hack over yap.c. yap.c
essentially initialises everything and then calls the predicate $live
over and over again. You can change your top-level by editing $live.

To extend Yap with new builtins one solution is to add files in the C
directory. In this case you will have functions of the form

/* returns either TRUE or FALSE */
static Int
p_whatever(void)
{
  /* get input args */
  Term t1 =3D Deref(ARG1);
  Term t2 =3D Deref(ARG2);
  /* check possible typing errors */
  if (IsVarTerm(t1)) {
   /* set up an error */
   Error(INSTANTIATION_ERROR, t1, "my message";
   /* fail */
   return(FALSE);
  }
  /* do something useful and place the result in term tf */
  tf =3D something_really_nice(t1, t2);
  /* we're done */
  return(unify(tf,ARG3));
}

at the end of the file you need to add your new predicates, which is
quite simple:

/* this is not static */
InitMyStuff()
{=20
  /* first argument is the name, second is arity, third is C-function,
last is flags (0 is safe) */
  InitCPred("whatever", 3, p_whatever, 0);
}

last, you need to call InitMyStuff from somewhere. A good place is
C/stdpreds.c in the function

InitCPreds();

> Thanks in advance for your help,
> Regards,
> Erick.
>=20

Hope this helps and feel free to ask more questions,

Regards,

V=EDtor