allocate len creates a C array of size len intialized with zeros of blst_fr

erase c overwrites a C array c with zeros of blst_fr

length c returns the length of a C array c

get c i returns the i-th element of a C array c

copy c returns a copy of a C array c

to_string c returns the string representation of a C array c

to_array c converts a C array c to an OCaml array

of_array c converts an OCaml array c to a C array

equal a b checks whether a C array a is equal to a C array b

Note: equal is defined as polynomial equality, i.e., a and b can have different sizes and padded with zeros of blst_fr