How to define function input type a struct from a different module?

New to Julia
1

I have just started to learn Julia. I am having difficulty defining function input type. Consider this 3 files:

#Mymodule.jl
module Mymodule
    export getP, point
    
    mutable struct point
        x::Int32
        y::Int32
    end

    function getP()::point
        return point(1,2)
    end
ende here

#Mymodule2.jl
module Mymodule2
    include("Mymodule.jl")
    using .Mymodule
    
    export mut1,mut2
    
    function mut1(a)
        a.x = -1
    end
    function mut2(a::point)
        a.x = -3
    end
end

#test.jl
include("Mymodule.jl")
using .Mymodule
include("Mymodule2.jl")
using .Mymodule2
a = getP()
println(a.x)
function mut3(a::point)
    a.x= -2
end
mut3(a)
mut1(a)
mut2(a)

Even though mut3() and mut1() works; mut2() does not. and gives the following error message:

ERROR: LoadError: MethodError: no method matching mut2(::point)
Closest candidates are:
  mut2(!Matched::Main.Mymodule2.Mymodule.point) at /home/saadmahmud/Documents/Halite/testjulia/Mymodule2.jl:11
Stacktrace:
 [1] top-level scope at none:0
 [2] include at ./boot.jl:317 [inlined]
 [3] include_relative(::Module, ::String) at ./loading.jl:1044
 [4] include(::Module, ::String) at ./sysimg.jl:29
 [5] exec_options(::Base.JLOptions) at ./client.jl:266
 [6] _start() at ./client.jl:425
in expression starting at /home/saadmahmud/Documents/Halite/testjulia/TestMain.jl:12

The only difference between mut1() and mut2() is that I defined the input type. What am I doing wrong?

2

What you are doing wrong is that you are including Mymodule.jl twice (once inside Mymodule2, once in test.jl). This effectively creates two copies of Mymodule, namely Base.Mymodule and Base.Mymodule2.Mymodule. Instead, you should remove the include("Mymodule.jl") in Mymodule2.jl and write using ..Mymodule on the following line.

1 Like
3

You might also find the discussion here relevant: Error with modules sharing types

1 Like
4

Thanks.

5

The discussion on organizing module was really helpful. Thanks.