Can I disable overloaded Base.show() and print the raw form of an object?

General Usage
1

Sometimes I’d like to see the “raw” form of a custom struct. Can I print it using the default Base.show(), ignoring my own custom definitions which print prettier results but may hide details useful for debugging?

2

I think you want the dump function.

3

Sometimes dump works, but when my struct contains nontrivial data structures like Dict, I’ll get lengthy unreadable results, because literally all the subfields are dumped. I just want to temporarily disable my overloaded version of Base.show, but maybe there’s just no good way to do that.

4

You can use the maxdepth keyword argument to control how deeply dump prints:

struct A{S, T}
    x::S
    y::T
end

a = A(1:4, Dict(:a => 1, :b => 2));

julia> dump(a; maxdepth=1)
A{UnitRange{Int64}, Dict{Symbol, Int64}}
  x: UnitRange{Int64}
  y: Dict{Symbol, Int64}
1 Like
5

You can use invoke(show, Tuple{IO,Any}, stdout, x) to invoke the default show(::IO, ::Any) method instead of any overloaded definition for x:

julia> invoke(show, Tuple{IO,Any}, stdout, pi)
Irrational{:π}()

Alternatively, you can call Base.show_default(io, x) (which happens to be what show(::IO, ::Any) calls), but invoke is the more general technique to call a less-specific method.

7 Likes