reflex-vty VS notcurses

There's a slick little Haskell library that does something similar called reflex-vty:

https://github.com/reflex-frp/reflex-vty#reflex-vty

One thing neither of these libraries appear to have done yet that I would really like is create a more compact window rendering. Currently each window gets a 1-character border. What I would like is something that saves space by collapsing adjacent windows' borders into a single character instead of having two redundant borders next to each other. Of course I get why they do it the way they do, but terminals are often more constrained for space and with complex UIs you can lose a fair amount due to these unnecessary borders. That would be the next thing I'd hack on to improve these kinds of libraries. But alas...too many fun projects to hack on and not enough hours in the day.

> The only reason we don't have animation frameworks for the terminal is because it's not possible

https://nick-black.com/dankwiki/index.php/Notcurses

Notcurses. Install it and run notcurses-demo to be suitably impressed.

Same for me, I would be much more motivated if there was something like textual for Rust. Given the capability of terminal emulators now I think Rust is lacking behind in the TUI field. Just checkout what can be done with something like notcurses

On the application side of rendering, see notcurses, it is at the leading edge: https://github.com/dankamongmen/notcurses

Other TUI libraries of note: https://github.com/dankamongmen/notcurses/blob/master/doc/OT...

The broader world probably knows him best for the terminal handling library Notcurses[1] and a lot of telling terminal emulator authors to get their shit together.

I’ve had his grad-school project libtorque[2] (HotPar ’10), an event-handling and scheduling library, on my to-read list for years, but I can’t seem to figure out how it accomplishes the interesting things it does.

[1] https://nick-black.com/dankwiki/index.php/Notcurses, https://github.com/dankamongmen/notcurses/

[2] https://nick-black.com/dankwiki/index.php/Libtorque

In XTerm, this (rightly) makes no difference. In Foot and Contour however, you still end up a line resp. a screen below where you started, if now with the correct horizontal position.

So it seems to me like what you want should work by default, except it doesn’t.

It should be possible to instead just treat the whole thing as a graphical overlay (by computing or directly asking for the character cell size, as Kirill Panov rightly admonishes me is possible with XTWINOPS) without touching the cursor; that’s what the “sixel scrolling” setting (DECSDM) is supposed to do. Then you can just manually move the cursor forward however many positions after you’re done drawing.

Except apparently the DEC manual (the VT330/340 one above) and DEC hardware contradict each other as to which setting of DECSDM (set or reset) corresponds to which scrolling state (enabled or disabled), and XTerm has implemented it according to the manual not the VT3xx[1,2,3]—then most other emulators followed suit[4]—then XTerm switched to following the hardware[5,6] (unless you and that’s what I’m seeing on my machine right now. So now you need to check if you’re on XTerm ≥ 369 or not[7]. If I’m reading the Notcurses code right, other terminals have followed suit[8].

Again, ouch.

P.S. It seems DEC had an internal doc for how their terminals should operate (DEC STD 070) [9]. It does not document DECSDM at all.

[1] https://github.com/wez/wezterm/issues/217#issuecomment-86449...

[2] https://github.com/hackerb9/lsix/issues/41

[3] https://github.com/dankamongmen/notcurses/issues/1782

[4] https://github.com/arakiken/mlterm/pull/23

[5] https://invisible-island.net/xterm/xterm.log.html#xterm_369

[6] https://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h3-T...

[7] https://github.com/dankamongmen/notcurses/commit/0918fa251e2... (the correct version cutoff is 369 not 359, the patch contains a now-fixed bug)

[8] https://github.com/dankamongmen/notcurses/blob/master/src/li... (look for mentions of invertsixel)

[9] http://www.bitsavers.org/pdf/dec/standards/EL-SM070-00_DEC_S...

And there's also the notcurses library: