Hands-On Design Patterns and Best Practices with Julia

Avoiding type piracy

Type II piracy can be mitigated by creating your own types and using them in the function argument. In this case, perhaps we should consider creating a wrapper type to hold the string and using this new type for dispatch:

module MyModule    export @str_str    import Base: +, show    struct MyString        value::AbstractString    end     macro str_str(s::AbstractString)         MyString(s)    end    show(io::IO, s::MyString) = print(io, s.value)    (+)(s::MyString, n::Number) = MyString(s.value * string(n))    (+)(n::Number, s::MyString) = MyString(string(n) * s.value)    (+)(s::MyString, t::MyString) = MyString(s.value * t.value)end

Here, we have redefined the module with a new MyString type that holds a string. Then, we can still extend the + function to concatenate ...