0/1 printing of false/true is confusing in Dict

[tkf]

julia> VERSION
v"1.2.0-DEV.146"

julia> show(Dict(true => false))
Dict(1=>0)

Also,

julia> Dict(true => false)
Dict{Bool,Bool} with 1 entry:
  true => false

seems to be inconsistent with

julia> [true => false]
1-element Array{Pair{Bool,Bool},1}:
 1 => 0

It looks like display(Dict(...)) does not set typeinfo while show(Dict(...)) does. Here is the code I used to check it:

function logio_show(io, mime)
    push!(logio_log, ("mime", mime))
    push!(logio_log, ("io isa IOContext", io isa IOContext))
    if io isa IOContext
        push!(logio_log, ("io.dict", io.dict))
    end
    print(io, "LogIO")
end

Base.show(io::IO, mime::MIME"text/plain", ::LogIO) =
    logio_show(io, mime)

Base.show(io::IO, ::LogIO) =
    logio_show(io, nothing)

then

empty!(logio_log)
display(Dict(:a=>LogIO()))
logio_log

shows

3-element Array{Any,1}:
 ("mime", nothing)                                                                                                
 ("io isa IOContext", true)                                                                                       
 ("io.dict", Base.ImmutableDict{Symbol,Any}(:compact=>true,:SHOWN_SET=>Dict(:a=>LogIO),:module=>Main,:limit=>true,:color=>true))

(i.e., no typeinfo) while

empty!(logio_log)
show(Dict(:a=>LogIO()))
logio_log

shows

3-element Array{Any,1}:
 ("mime", nothing)                                                                                                
 ("io isa IOContext", true)                                                                                       
 ("io.dict", Base.ImmutableDict{Symbol,Any}(:typeinfo=>LogIO,:compact=>true,:compact=>true,:typeinfo=>Pair{Symbol,LogIO},:SHOWN_SET=>Dict(:a=>LogIO),:color=>true))

i.e., typeinfo is set to LogIO.

[stevengj]

The show(io, dict) method sets :typeinfo here, which it shouldn't since it doesn't print the type. Whereas the show(io, text/plain, dict) method fails to set :typeinfo here.

[stevengj]

That being said, we may want to think about disabling printing of boolean values as 0/1 when printing dict (or maybe in general for printing pairs and tuples even if the typeinfo indicates a Bool field).

[stevengj]

Would be good to revisit this.

[JeffBezanson]

This might be another case where a parseable or repr printing flag would make sense.

[tkf]

a parseable or repr printing flag would make sense

Please see #33260

[stevengj]

This might be another case where a parseable or repr printing flag would make sense.

That seems orthogonal to the present issue, which is simply that typeinfo is being set incorrectly.

[logankilpatrick]

@JeffBezanson @stevengj Can you add some context as to why this behavior exists:

d = [true, false, true]
3-element Vector{Bool}:
1
0
1

instead of showing true, false, true in the output?

[KristofferC]

#30575 is the context. Now, one could ask the question if it is worth printing it compactly like that for a Vector{Bool} where every element is on its own line.