Specman: Error in on-the-fly generating of list of lists with all different values - specman

Question

I try to generate on-the-fly list of list of uint (my_list_of_list) with all different values (I have a variable num_of_ms_in_each_g : list of uint, that keeps lengths of every list inside my_list_of_list):
var my_list_of_list : list of list of uint;
gen my_list_of_list keeping {
for each (g) using index (g_idx) in it {
g.size() == num_of_ms_in_each_g[g_idx];
for each (m) using index (m_idx) in g {
// Error in the next line:
m not in it[0..g_idx-1][0..num_of_ms_in_each_g[g_idx]-1];
m not in it[g_idx][0..max(0, m_idx-1)];
};
};
Explanation for the code algorithm: generate m (the value) that was not yet in any list of uint (g) before, and does not appear in current list for previous indexes.
I get compilation error:
*** Error: 'm' is of type 'uint', while expecting type 'list of uint' or
'list of list of uint'.
Do you have any idea how to solve the compilation error? (it[0..g_idx-1][0..num_of_ms_in_each_g[g_idx]-1] is uint..) Or maybe another way to generate on-the-fly list of list of uint with all different values?
Thank you for your help.

Answer 1

I would reduce the complexity of this constraint by using a sort of a unified list that contains all the items, and then
Break this list into the desired list of list ( as It is easier to generate a single unique list).
Also, in general, it is best to keep all non-generative operations outside of the constraints since it could be done procedurally
Afterwards which will improve the overall performance of generating such a field set.
I would do this using the following code:
var unified_list:list of uint;
var my_list_of_list : list of list of uint;
gen unified_list keeping {
it.size()==num_of_ms_in_each_g.sum(it);
it.all_different(it);
};
for each in num_of_ms_in_each_g {
var temp_list:list of uint;
for i from 0 to it-1 {
temp_list.add(unified_list.pop0());
};
my_list_of_list.add(temp_list);
};
thanks

Answer 2

Actually, the expression it[0..g_idx-1][0..num_of_ms_in_each_g[g_idx]-1] is of type list of list of uint. The operator list[from..to] produces a sub list. In your code you apply it twice to it which first produces a sublist and then produces a sublist of the sublist.
The second such constraint in your code works, because it[g_idx] does not produce a sublist, but rather accesses a list item, which is of type list of uint and then produces a sublist.
To produce an all different list of list I would do something like:
var my_list_of_list : list of list of uint;
for each (sz) in num_of_ms_in_each_g {
var l : list of uint;
gen l keeping {
it.size() == sz;
it.all_different(it);
// not it.has(it in my_list_of_list.flatten());
// for better performance
for each (itm) in it {
itm not in my_list_of_list.flatten();
};
};
my_list_of_list.add(l);
};