Using struct from a module inside another module in Julia

Question

I have found similar questions on SO but none of them seem to give an answer that works for my case.

I have a few modules, in one of them I create a mutable struct which I want to be able to use in the others. All files are at the same level:

• file_module_A.jl
• file_module_B.jl
• file_module_C.jl

In file_module_A.jl:

module A
   mutable struct MyType
      variable
   end
end

In file_module_B.jl:

module B
    # I need to import MyType here
end

In file_module_C.jl:

module C
    # I need to import MyType here
end

I have tried the followings without success:

• Using directly: using .A doesn't work
• I can't use: include("./file_module_A.jl") in both B and C because when they interact between each other I get the error can't convert from Main.B.A to Main.C.A since include includes a copy of the whole code

Any ideas? Thanks in advance!

Answer 1

You need to use using ..A. using .A means to look for A in the current module (B in the example below), and you need an extra . to step up one module level, to Main if you run the example in the REPL:

module A
    mutable struct MyType
        variable
    end
end

module B
    using ..A: MyType
end