feat(repl): Add key binding to force a new line

[sigmaSd]

Add Alt Enter key binding to force a new line, usually this is used when you write a single line and then you want to break it.

[CLAassistant]

All committers have signed the CLA.

[bartlomieju]

@sigmaSd thanks for opening the PR. What's the reasoning for this functionality? If it is a popular binding, I'd expect that rustyline would implement it out-of-the-box.

[imjamesb]

Would this also work on a Mac whereas Mac has the option key, not alt?

[sigmaSd]

I'm ok with any keybidings, if It doesn't work we can change it to ctrl but I don't have a mac to test.

Regarding rustyline, it follows emacs and vi editor keys but the difference is in an editor the enter key is unambiguous it always means a new line, in a repl it can either mean a new line or a eval request, that's why we rely on heuristics such as is the parentheses balenced or not, but there are cases when heuristics can fail and you simply want to add a new line for example when refactoring a single to line to a multiline.

I can add a demo of how this looks like if it's still unclear.

[sigmaSd]

Here is a random example where I want to refactor the initial one-liner to a function, In this case the heuristic would fail because the input is valid and it will try to evaluate it, that's why I'm forcing new lines.

deno3.mov

[sigmaSd]

For precedence, I just noticed that fish shell has this feature and its also bound to Alt+enter

[bartlomieju]

@sigmaSd sounds good, we can add it. Please merge with main and open a PR to https://github.com/denoland/manual that updates REPL chapter with this binding

[sigmaSd]

done

[dsherret]

This doesn't seem to work in Windows terminal or command prompt—the terminal goes full screen when I press alt+enter.

[sigmaSd]

Guess its bound already, I can try ControlEnter or shiftEnter

[sigmaSd]

shiftenter and ctrlenter doesn't seem to work on linux, do you have a suggestion for a keybinding?

[sigmaSd]

I can also make it platform dependent, alt enter on Linux Mac, and maybe shift or ctrl enter on windows if one of those works

[bartlomieju]

I know @lucacasonato was interested in this issue. Luca WDYT?

[sigmaSd]

I changed the keybinding to CTRL-S, at least that should work cross platform.

[bartlomieju]

LGTM, thanks @sigmaSd!

[jsejcksn]

@bartlomieju @dsherret In the blog post release notes, this is listed with a capital S:

Using Ctrl + S combination you can now force a new line when editing code in the REPL

However, the sequence requires lowercase s. I think this is probably assumed by hardware keyboard users because of convention, but many software keyboards allow input of different letter forms without modifier keys, so the information in the release notes is incorrect.

Can it be changed to ctrl + s? It's not clear where to post issues about the blog release notes, so I'm posting here.

[bartlomieju]

You mean you want to change the blog post to use ctrl + s instead of Ctrl + S?

[jsejcksn]

You mean you want to change the blog post to use ctrl + s instead of Ctrl + S?

@bartlomieju Yes, exactly.

It's not clear where to post issues about the blog release notes, so I'm posting here.

Also, where is the official issue tracker for the blog?

[bartlomieju]

You mean you want to change the blog post to use ctrl + s instead of Ctrl + S?

@bartlomieju Yes, exactly.

Sure I can change it.

It's not clear where to post issues about the blog release notes, so I'm posting here.

Also, where is the official issue tracker for the blog?

You can post issues in deno repository, the blog is in a private repo.

[bartlomieju]

@jsejcksn this is fixed now in the blog post.