Hi Joshua, I almost forgot about your talk, but I remember watching it and you definitely inspired me years ago. I should have included a link to your talk, thanks for reminding me! Let me know if you ever want to chat about this topic.

Hi Wolf, not sure what you are testing. Note that the timing depends on how you test it. The any(x -> x < 3, numbers) might look slow if you use @time , but that's because the anonymous function keeps getting recompiled for every call. Maybe that's what you mean? You can easily bypass this by placing it inside another function. Also you can use BenchmarkTools.@btime instead to ignore the compilation time. julia> numbers = [ 1 , 2 , 3 , 4 , 5 ]; julia> @time any(x -> x < 3 , numbers) 0.006801 seconds ( 2.74 k allocations: 183.680 KiB, 99.01 % compilation time) true julia> @time any(numbers .< 3 ) 0.000012 seconds ( 3 allocations: 128 bytes) true julia> any_less(numbers, value) = any(x -> x < value, numbers) any_less (generic function with 1 method) julia> @time any_less(numbers, 3 ) # first call compiles the `any_less` 0.009657 seconds ( 6.90 k allocations: 456.047 KiB, 99.76 % compilation time) true julia> @time any_less(numbers, 3 ) # now it's fast 0.000005 seconds true But perhaps you are talking about something else?

After reading these discussions, I may have interpreted :compact in the wrong way, it's not intended for switching between single-line and multi-line displaying. Also the philosophy of the 2-argument show(io::IO, t::MyType) is that it always returns an expression that can be evaluated, kinda like the constructor. You do not want compact mode to accidentally switch it to a multi-line printing.

Found another summary of all show/print options, which will be added to the Julia docs: https://discourse.julialang.org/t/how-to-display-a-sparse-array-on-the-repl/113565/5 And this discussion: https://discourse.julialang.org/t/print-vs-two-argument-show-repr-vs-three-argument-show-repr-with-mime-text-plain/117790

Just found out the manual has a section on this topic: https://docs.julialang.org/en/v1/manual/types/#man-custom-pretty-printing

Would you say there's a difference in the effectiveness of the structures I compare? They all seem rather easy to use and understand to me.

I can't really imagine that it's ever a big factor in your decision. People may have a preference, I prefer the in-language approach, but compiled languages like Rust/C++/etc don't even use a REPL, so then keeping it outside makes sense.

cool, thanks for yet another suggestion :)

I must admit I don't use Pluto a lot myself ;) But since Pluto itself is barely ever used inside other code, we could consider it a REPL utility, so I'd say it's pretty safe to add it to the global environment. Pluto will start a separate environment for you anyway once you launch it.

Nice overview! Some of my engineers have also tried out Oxygen.jl which is a micro-framework around HTTP.jl, adding a little extra elegance.