nativelite-vterm 0.5.4

Added

• Mouse tracking modes (?1000, ?1002, ?1003, and ?1006 SGR
  encoding): Term::mouse_tracking (MouseTracking::Off/Click/Drag/Motion)
  and Term::mouse_sgr, so a host knows when a program wants the mouse
  reported. Not kept in checkpoints: a restored screen starts with it off.

Changed

• Plain text is written straight into the screen (ansi::Screen::write_ascii)
  instead of through a scratch buffer of cells. With ansi's lazy row
  clearing and faster UTF-8 decoding, Term::feed on agent output (177x47)
  went from 188 to 330 MiB/s.
• The ASCII check on text runs is a word-wide is_ascii, since the parser
  never passes controls in text. With ansi's faster text skip, Term::feed
  is now 570 MiB/s on the same workload.
• Plain ASCII text skips UTF-8 decoding when no character is half-received
  (ansi::Utf8Decoder::is_idle): 570 -> 631 MiB/s.

Added

• Scrollback: Term::with_history(rows, cols, lines) keeps up to lines
  lines scrolled off the primary screen (ansi::Screen::with_history), read
  through Term::scrollback(). It survives a resize; ESC [3J erases it; the
  alternate screen and scroll regions never add to it. in_alternate_screen()
  tells a host when scrolling back does not apply. Synchronized-output
  snapshots copy the visible rows only.
• New line mode (LNM, CSI 20 h / CSI 20 l): while set, LF, VT and FF
  also return to column 0. For hosts feeding output from plain pipes, where no
  tty turns LF into CR LF. Kept in checkpoints (flag bit 7; older checkpoints
  restore with it off).

Added

• Checkpoints: Term::checkpoint() and Term::restore(). A terminal's
  whole state as bytes and back: both screens, cursor, style, scroll region,
  tab stops, saved cursor, modes and a synchronized update in progress.
  Feeding a restored Term the rest of a stream ends in exactly the state of
  one that never stopped — tested at every split point of a stream exercising
  all of that state, and across chunked feeds.
  • Taken only between sequences (Term::can_checkpoint(), via
    ansi::Parser::is_ground()), so the tokenizer never needs saving.
  • Versioned, run-length encoded, and validated on restore: damaged bytes are
    an error (RestoreError), never a panic.
  • Measured (release, i5-12600K): 24x80 full of coloured build output,
    19.7 KB, save 23 us, restore 63 us; 50x200, 42.1 KB, 111 us / 93 us.