Invalid redefinition when redefining an identical parameterized type

[Kristoffer Carlsson]

I have a file that defines a type and a few functions. Sometimes I want to reload this file in the REPL to update some modified functions in the file. If the type is parameterized then this will fail even though the type definition does not change.

Example:

julia> type Foo

       a::Int

       end

julia> type Foo

       a::Int

       end

julia> type Foo2{T}

       a::T

       end

julia> type Foo2{T}

       a::T

       end

ERROR: invalid redefinition of constant Foo2

Is there a good way to work around this? I don't really want to workspace() all the time because then I have to compile everything again.

[Stefan Karpinski]

Defining types in a module and then reloading the module helps. The bindings get messy though, so it's best to qualify all accesses when you're developing like that. This is kind of an annoyance – not sure how hard it would be to fix but it should be doable.

[Kristoffer Carlsson]

Modules might work but they bring other annoyances... I would be fine with a warning and just ignoring the whole type block.

Similar to:

julia> const a = 1

1

julia> const a = 2

WARNING: redefining constant a

2

couldn't it be:

julia> type Foo2{T}

       a::T

       end

julia> type Foo2{T}

       a::T

       end

WARNING: did not redefine constant Foo2

[Stefan Karpinski]

You could also make the type definition conditional and only evaluate it if it isn't already defined.

[Kristoffer Carlsson]

Ah, that's a good idea! Thanks!