Repl history should cycle through top level forms

[allison-casey]

It would be nice if HyREPL cycled through entire forms when looking through the history like IPython instead of just by line. It would make working in the repl a much nicer experience. So pressing up in a case like this:

=> (defn test [name]
... (print "Hello" name))
=> 

would get you

=> (defn test [name]
... (print "Hello" name))
=> (defn test [name]
... (print "Hello" name))

and not

=> (defn test [name]
... (print "Hello" name))
=> (defn test [name]

[peaceamongworlds]

The default Python repl seems to do the same thing. Would this not be solved by using the hy repl through something like hy-mode in Emacs, or using a hy kernel for IPython?

[scauligi]

Sure, but if we can make our REPL nicer on its own I think that's still worthwhile.

[Kodiologist]

Python 3.13 has a fancy new built-in REPL, which we might be able to take advantage of.

[atisharma]

I subclassed the hy REPL to implement multi-line editing so you can cycle through top-level forms.

It also has (live) syntax highlighting for forms and tracebacks, completion and so on.
It is here.

However, I used pygments and prompt-toolkit. The latter especially is relatively large, about 5MB on pypi. I think it is too large to be the standard REPL given hy itself is about 120k.
I looked at modifying the standard readline input instead but it got too ugly. If you want to adopt it here, that is fine, if not, that is fine too.

Anyway, it now exists, so I thought it was relevant to this issue.

[Kodiologist]

Yeah, prompt_toolkit is probably fancier than we want to get for something built into Hy.