const cst_val *set_car(cst_val *v1, const cst_val *v2)
{
/* destructive set car, be careful you have a pointer to current cdr */
if (!cst_val_consp(v1))
{
cst_errmsg("VAL: tried to set car of non-consp cell\n");
cst_error();
return NULL;
}
else
{
val_dec_refcount(CST_VAL_CAR(v1));
val_inc_refcount(v1);
CST_VAL_CAR(v1) = (cst_val *)v2;
}
return v1;
}
void delete_val(cst_val *v)
{
if (v)
{
if (cst_val_consp(v))
{
delete_val(CST_VAL_CAR(v));
delete_val(CST_VAL_CDR(v));
cst_free(v);
}
else if (val_dec_refcount(v) == 0)
{
if (CST_VAL_TYPE(v) == CST_VAL_TYPE_STRING)
cst_free(CST_VAL_VOID(v));
else if (CST_VAL_TYPE(v) >= CST_VAL_TYPE_FIRST_FREE)
(cst_val_defs[CST_VAL_TYPE(v)/2].delete_function)(CST_VAL_VOID(v));
cst_free(v);
}
}
}
