Overload show(io, mime, x) instead of show(io, x) for pretty-printing.

[fredrikekre]

I think the three-arg method is recommended for pretty-printing. Otherwise the pretty-printing leaks out in e.g. error messages.

[timholy]

If you can fix CI, I approve. Thanks!

[fredrikekre]

The failures are doctest failures, and those make me think this is not a good change, since two-arg show is used when printing containers. For example the breakpoint example will turn from

julia> frame, bp = @interpret sum([1,2,5])
(Frame for sum(a::AbstractArray) in Base at reducedim.jl:645
c 1 645      1 ─      nothing
  2 645  645 │   %2 = (Base.#sum#538)(Colon(), #self#, a)
  3 645      └──      return %2
a = [1, 2, 5], breakpoint(sum(a::AbstractArray) in Base at reducedim.jl:645, line 645))

to

julia> frame, bp = @interpret sum([1,2,5])
(Frame(JuliaInterpreter.FrameCode(sum(a::AbstractArray) in Base at reducedim.jl:648, CodeInfo(
1 ─      nothing
│   @ reducedim.jl:648 within `sum'
│   %2 = ($(QuoteNode(Base.#sum#558)))($(QuoteNode(Colon())), #self#, a)
└──      return %2
), Union{Compiled, Core.TypeMapEntry}[#undef, #undef, #undef], JuliaInterpreter.BreakpointState[JuliaInterpreter.BreakpointState(true, ##slotfunction#373), #undef, #undef], BitSet([2]), false), JuliaInterpreter.FrameData(Union{Nothing, Some{Any}}[Some(sum), Some([1, 2, 5])], Any[#undef, #undef, #undef], Any[], Int64[], Base.RefValue{Any}(nothing), Dict(:a => 2,Symbol("#self#") => 1), Any[]), 1, nothing, nothing), BreakpointRef(JuliaInterpreter.FrameCode(sum(a::AbstractArray) in Base at reducedim.jl:648, CodeInfo(
1 ─      nothing
│   @ reducedim.jl:648 within `sum'
│   %2 = ($(QuoteNode(Base.#sum#558)))($(QuoteNode(Colon())), #self#, a)
└──      return %2
), Union{Compiled, Core.TypeMapEntry}[#undef, #undef, #undef], JuliaInterpreter.BreakpointState[JuliaInterpreter.BreakpointState(true, ##slotfunction#373), #undef, #undef], BitSet([2]), false), 1, nothing))

because there is a tuple returned. The examples can of course be updated to display them separately like so:

julia> frame, bp = @interpret sum([1,2,5]);

julia> frame
Frame for sum(a::AbstractArray) in Base at reducedim.jl:648
c 1 648  1 ─      nothing
  2 648  │   @ reducedim.jl:648 within `sum'
  3 648  │   %2 = (Base.#sum#558)(Colon(), #self#, a)
Variable([1, 2, 5], :a, false)

julia> bp
breakpoint(sum(a::AbstractArray) in Base at reducedim.jl:648, line 648)

I don't really know what is "correct", but from JuliaLang/julia#30757 (comment) it sounds like three-arg should be used for pretty-printing. Also, with the PR as is, the fact that both Method and CodeInfo pretty-prints with two-arg makes things look weird anyway.

[fredrikekre]

Actually, the docs for show say that

The default MIME type is MIME"text/plain". There is a fallback definition for text/plain output that calls show with 2 arguments. Therefore, this case should be handled by defining a 2-argument show(io::IO, x::MyType) method.

which contradicts the link from the previous post.

[KristofferC]

Think we just ignore this for now.