C API - null symbols

Community Support
1

linking from Stack Overflow here. Can anyone help me out?

2

Not an expert on this matter, but can you try comparing the values instead? Also, may need to cast explicitly to symbol:

K test (K x) { K ns = ks((S)""); if (abs(x->t) != KS) { R krr((S)"type"); } if (x->t > 0) { K res = ktn(KB,x->n); for (int i=0;i<x->n;++i){ if (ks(kS(x)[i])->s == ns->s) { kG(res)[i] = 1; } else { kG(res)[i] = 0; } } R res; } else { if (x->s == ns->s) { R kb(1); } else { R kb(0); } }}
3

Not an expert on this matter, but can you try comparing the values instead? Also, may need to cast explicitly to symbol:

K test (K x) { K ns = ks((S)""); if (abs(x->t) != KS) { R krr((S)"type"); } if (x->t > 0) { K res = ktn(KB,x->n); for (int i=0;i<x->n;++i){ if (ks(kS(x)[i])->s == ns->s) { kG(res)[i] = 1; } else { kG(res)[i] = 0; } } R res; } else { if (x->s == ns->s) { R kb(1); } else { R kb(0); } }}

?

4

Hi Ethel,

I responded to the post.

You only care about the the underlying char array in each case so you need to compare this rather than the entire k object

Also ensure any k objects are dereferenced when finished with

Thanks

5

if you make ‘ns’ static, you don’t need to allocate it each time and then remember to free it afterwards.

this requires the use of g++ instead of gcc (and also the ‘extern “C”’ wrapper).

i see you are using some of the macros in k.h.  if we go ‘all-in’, we can also remove the stinking loops and conditionals. the result is, imho, much easier to read:

extern “C” {
K1(test) {
  ZK ns = ks((S)“”);
  K r;
 
  SW(xt) {
    CS(-KS,r = kb(xs==ns->s));
    CS( KS,r = ktn(KB,xn); DO(xn,kG(r)[i] = ns->s==xS[i]));
    CD:    r = krr((S)“type”);
  }
  R r;
}
}

here are a few tests:

q)x:``foo

q)test x
10b
q)test each x
10b
q)test enlist x
'type
  [0]  test enlist x
       ^