I may have this problem:
I have module a, which defines type A with private field a and also field v of
type b.B And I have module b, which defines type B with private field b and
also field w of type a.A
# Module a:
type
A* = object
a: int
v: B
# Module b:
type
B* = object
b: int
w: A
Run
One solution is to create a third module, maybe called types, put both type
definitions there and import that module from modules a and b.
But then module a can not access field A.a! So I have to mark field a by a *
star to export it. But then module b can also access field a, which was not
initially intended.
I think in Modula/Oberon recursive/mutual import was solved by separate
definition and implementation modules if I remember correctly.
Solutions: Joining modules a and b, or including one from the other. Or using
third module types and exporting all members.
Seems all not really nice. Modules a and b are in this case vertices and edges
of a triangulation, in C++ generally defined in separate header files with
mutual include.
In some languages we can just declare a type, without defining it, so that
compiler knows it is a valid type, but I think Nim does not allow that (forward
declaration).
