Overriding Base.show with multi-line string returns literal "\n"

New to Julia
,
1

Hi,
I have a composite struct ABC with various fields A,B,C, which I want to display in a clear way on the screen (and later in Jupyter, but starting with REPL/console).

Here’s my code:

struct ABC
    A::Vector{Int64}
    B::Vector{Float32}
    C::Vector{String}
end

abc = ABC(
    [1,2,3],
    [4.5, 6.7, 8.9],
    ["hello", "world"]
)

function Base.show(io::IO, x::ABC)
    show(io,
    """
    A:
        $(x.A)
    
    B:
        $(x.B)

    C:
        $(x.C)
    """)
end

println(abc)

However, it shows a string with “\n” rather than actual newlines:

"A:\n    [1, 2, 3]\n\nB:\n    Float32[4.5, 6.7, 8.9]\n\nC:\n    [\"hello\", \"world\"]\n"

What am I missing?

Note: also tried PrettyPrint.jl and PrettyPrinting.jl but they seem to return similar output to print for this case.

2

Inside your Base.show implementation, you want to call print, not show on the string. show will always give you some output that you can ideally copy-and-paste into the REPL and get back the same object. print is for when you want to just print the string as-is, but it falls back to show for most other objects.

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