c99_table_ex.c

#include <stddef.h>
#include <stdio.h>

typedef void MyFunc(void);

typedef struct {
  int a;
  int b;
  MyFunc *c;
} MyTransition;

typedef struct {
  size_t x;
  size_t y;
} MyDim;

#define MyTableXY(n, dim_y, dim_x, ...)                                        \
  struct {                                                                     \
    MyDim dim;                                                                 \
    MyTransition transitions[dim_y][dim_x];                                    \
  } n = {.dim = {.x = dim_x, .y = dim_y}, .transitions = {__VA_ARGS__}}

#define MyTableXYToArg(t) &t.dim, &t.transitions[0][0]
#define MyTableXYArg(d, t) MyDim const *d, MyTransition const *t
#define MyTableXYTrans(t, y, x) t.transitions[y][x]

static void printTable(MyTableXYArg(dim, trans)) {
  printf("Dim x = %lu, Dim y = %lu\n\n", dim->x, dim->y);
  for (size_t cnt = 0; cnt < dim->x * dim->y; cnt++) {
    printf("{%d, %d}", trans[cnt].a, trans[cnt].b);
    if ((cnt + 1) % dim->x == 0) {
      printf("\n");
    } else {
      printf(", ");
    }
  }
  printf("\n");
}

static void foo(void) { printf("foo\n"); }
static void bar(void) { printf("bar\n"); }

int main(void) {
  MyTableXY(myTable, 3, 2, {{0, 1, &foo}, {2, 3, &bar}});

  printTable(MyTableXYToArg(myTable));
  MyTableXYTrans(myTable, 0, 0).c();
  MyTableXYTrans(myTable, 0, 1).c();

  return 0;
}