ilists.c: Icon-to-C interface for simple Icon lists

link cfunc
April 26, 2002; Kostas Oikonomou
This file is in the public domain.

This file provides three procedures for translating homogeneous
lists of integers, reals, or strings to C arrays:

    IListVal(d) returns an array of C ints.
    RListVal(d) returns an array of C doubles.
    SListVal(d) returns an array of C char pointers (char *).
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Here is an example of using this interface:

1. gcc -I/opt/icon/ipl/cfuncs -shared -fPIC -o llib.so l.c
where "l.c" is the C fragment below.

#include "ilists.c"
int example(int argc, descriptor argv[])
{
  int *ia;
  double *ra;
  char *(*sa);
  int n;  int i;
  ArgList(1);  n = ListLen(argv[1]);
  ia = IListVal(argv[1]);
  for (i=0; i<n; i++) printf("%i ", ia[i]); printf("\n");
  ArgList(2);  n = ListLen(argv[2]);
  ra = RListVal(argv[2]);
  for (i=0; i<n; i++) printf("%f ", ra[i]); printf("\n");
  ArgList(3);  n = ListLen(argv[3]);
  printf("n = %i\n", n);
  sa = SListVal(argv[3]);
  for (i=0; i<n; i++) printf("%s ", sa[i]); printf("\n");
  Return;
}

2. The Icon program that loads "example" from the library llib.so:

procedure main()
   local e, L1, L2, L3
   e := loadfunc("./llib.so", "example")
   L1 := []
   every i := 1 to 5 do put(L1,10*i)
   L3 := ["abcd","/a/b/c","%&*()","","|"]
   e(L1,[1.1,2.2,-3.3,5.5555],L3)
   end