REPL integrated readline

[toivoh]

I feel that this has been discussed before, but I couldn't find an issue. Anyway, now that #6270 has had the chance to simmer for quite a bit, it would be nice if also user code could make use of the readline functionality provided by the new REPL.

I'm not sure if this should be special cased on calling readline(STDIN) (or just readline()), or if there should be a new function (with more options?). Also, not sure how this should work with eg IJulia.

This would e.g. be really useful to improve the debugging experience with Debug.jl. I'm sure there's others who would benefit as well.

[KristofferC]

readline() now seems to wait for STDIN. Ok to close?

[tkelman]

Isn't this referring to tab completion etc in user input?

[KristofferC]

I don't know.

[rfourquet]

I don't understand the issue here, could someone clarify what is requested here?

[timholy]

julia> readline()
Once upp^A
"Once upp\x01"

That ^A was me trying to go back to the beginning of the line using readline commands. The issue is requesting documentation about how one might turn that on.

[KristofferC]

The "correct" way to do this seems to me to be to implement a new REPL mode (like Debugger and Pkg does) and not call readline explicitly. So I don't think there is much to do here.