Sequences documented in parens are implicit ones from parser.c, which move
between states.

1 = VT100
2 = VT220
3 = VT320

   C0 controls

123   0x00             = NUL
123   0x07             = BEL
123   0x08             = BS
123   0x09             = HT
123   0x0A             = LF
123   0x0B             = VT
123   0x0C             = FF
123   0x0D             = CR
123   0x0E             = LS1
123   0x0F             = LS0
     (0x18             = CAN)
     (0x1A             = SUB)
     (0x1B             = ESC)

123   0x7f             = DEL (ignored)

   C1 controls

123   0x84             = IND
123   0x85             = NEL
123   0x88             = HTS
123   0x8D             = RI
 23   0x8e             = SS2
 23   0x8f             = SS3
     (0x90             = DCS)
     (0x9B             = CSI)
     (0x9C             = ST)
     (0x9D             = OSC)

   Escape sequences
    - excluding sequences that are C1 aliases

123   ESC ()           = SCS, select character set (G0, G1)
 23   ESC *+           = SCS, select character set (G2, G3)
123   ESC 7            = DECSC - save cursor
123   ESC 8            = DECRC - restore cursor
123   ESC # 3          = DECDHL, double-height line (top half)
123   ESC # 4          = DECDHL, double-height line (bottom half)
123   ESC # 5          = DECSWL, single-width single-height line
123   ESC # 6          = DECDWL, double-width single-height line
123   ESC # 8          = DECALN
123   ESC <            = Ignored (used by VT100 to exit VT52 mode)
123   ESC =            = DECKPAM, keypad application mode
123   ESC >            = DECKPNM, keypad numeric mode
 23   ESC Sp F         = S7C1T
 23   ESC Sp G         = S8C1T
     (ESC P            = DCS)
     (ESC [            = CSI)
     (ESC \            = ST)
     (ESC ]            = OSC)
123   ESC c            = RIS, reset initial state
  3   ESC n            = LS2
  3   ESC o            = LS3
  3   ESC ~            = LS1R
  3   ESC }            = LS2R
  3   ESC |            = LS3R

   DCSes

  3   DCS $ q      ST  = DECRQSS
  3           m        =   Request SGR
              Sp q     =   Request DECSCUSR
  3           " q      =   Request DECSCA
  3           r        =   Request DECSTBM
              s        =   Request DECSLRM

   CSIs
 23   CSI @            = ICH
123   CSI A            = CUU
123   CSI B            = CUD
123   CSI C            = CUF
123   CSI D            = CUB
      CSI E            = CNL
      CSI F            = CPL
      CSI G            = CHA
123   CSI H            = CUP
      CSI I            = CHT
123   CSI J            = ED
 23   CSI ? J          = DECSED, selective erase in display
123   CSI K            = EL
 23   CSI ? K          = DECSEL, selective erase in line
 23   CSI L            = IL
 23   CSI M            = DL
 23   CSI P            = DCH
      CSI S            = SU
      CSI T            = SD
 23   CSI X            = ECH
      CSI Z            = CBT
      CSI `            = HPA
      CSI a            = HPR
      CSI b            = REP
123   CSI   c          = DA, device attributes
123       0            =   DA
 23   CSI >   c        = DECSDA
 23         0          =   SDA
      CSI d            = VPA
      CSI e            = VPR
123   CSI f            = HVP
123   CSI g            = TBC
123   CSI h            = SM, Set mode
123   CSI ? h          = DECSM, DEC set mode
      CSI j            = HPB
      CSI k            = VPB
123   CSI l            = RM, Reset mode
123   CSI ? l          = DECRM, DEC reset mode
123   CSI m            = SGR, Set Graphic Rendition
123   CSI   n          = DSR, Device Status Report
 23       5            =   operating status
 23       6            =   CPR = cursor position
 23   CSI ? n          = DECDSR; behaves as DSR but uses CSI ? instead of CSI to respond
 23   CSI ! p          = DECSTR, soft terminal reset
  3   CSI ? $ p        = DECRQM, request mode
      CSI   Sp q       = DECSCUSR (odd numbers blink, even numbers solid)
          1 or 2       =   block
          3 or 4       =   underline
          5 or 6       =   I-beam to left
 23   CSI " q          = DECSCA, select character attributes
123   CSI r            = DECSTBM
      CSI s            = DECSLRM
      CSI ' }          = DECIC
      CSI ' ~          = DECDC

   OSCs

      OSC 0;           = Set icon name and title
      OSC 1;           = Set icon name
      OSC 2;           = Set title

   Standard modes

 23   SM 4             = IRM
123   SM 20            = NLM, linefeed/newline

   DEC modes

123   DECSM 1          = DECCKM, cursor keys
123   DECSM 5          = DECSCNM, screen
123   DECSM 6          = DECOM, origin
123   DECSM 7          = DECAWM, autowrap
      DECSM 12         = Cursor blink
 23   DECSM 25         = DECTCEM, text cursor enable
      DECSM 69         = DECVSSM, vertical screen split
      DECSM 1000       = Mouse click/release tracking
      DECSM 1002       = Mouse click/release/drag tracking
      DECSM 1003       = Mouse all movements tracking
      DECSM 1004       = Focus in/out reporting
      DECSM 1005       = Mouse protocol extended (UTF-8) - not recommended
      DECSM 1006       = Mouse protocol SGR
      DECSM 1015       = Mouse protocol rxvt
      DECSM 1047       = Altscreen
      DECSM 1048       = Save cursor
      DECSM 1049       = 1047 + 1048
      DECSM 2004       = Bracketed paste

   Graphic Renditions

123   SGR 0            = Reset
123   SGR 1            = Bold on
      SGR 3            = Italic on
123   SGR 4            = Underline single
      SGR 4:x          = Underline style
123   SGR 5            = Blink on
123   SGR 7            = Reverse on
      SGR 8            = Conceal on
      SGR 9            = Strikethrough on
      SGR 10-19        = Select font
      SGR 21           = Underline double
 23   SGR 22           = Bold off
      SGR 23           = Italic off
 23   SGR 24           = Underline off
 23   SGR 25           = Blink off
 23   SGR 27           = Reverse off
      SGR 28           = Conceal off
      SGR 29           = Strikethrough off
      SGR 30-37        = Foreground ANSI
      SGR 38           = Foreground alternative palette
      SGR 39           = Foreground default
      SGR 40-47        = Background ANSI
      SGR 48           = Background alternative palette
      SGR 49           = Background default
      SGR 90-97        = Foreground ANSI high-intensity
      SGR 100-107      = Background ANSI high-intensity

The state storage used by ESC 7 and DECSM 1048/1049 is shared.

   Unimplemented sequences:

The following sequences are not recognised by libvterm.

123   0x05             = ENQ
  3   0x11             = DC1 (XON)
  3   0x13             = DC3 (XOFF)
12    ESC Z            = DECID, identify terminal
      DCS $ q          = [DECRQSS]
  3           " p      =   Request DECSCL
  3           $ }      =   Request DECSASD
  3           $ ~      =   Request DECSSDT
 23   DCS {            = DECDLD, down-line-loadable character set
 23   DCS |            = DECUDK, user-defined key
 23   CSI i            = DEC printer control
 23   CSI " p          = DECSCL, set compatibility level
1     CSI q            = DECLL, load LEDs
  3   CSI   $ u        = DECRQTSR, request terminal state report
  3       1            =   terminal state report
  3   CSI & u          = DECRQUPSS, request user-preferred supplemental set
  3   CSI   $ w        = DECRQPSR, request presentation state report
  3       1            =   cursor information report
  3       2            =   tab stop report
1     CSI x            = DECREQTPARM, request terminal parameters
123   CSI y            = DECTST, invoke confidence test
  3   CSI $ }          = DECSASD, select active status display
  3   CSI $ ~          = DECSSDT, select status line type
 23   SM 2             = KAM, keyboard action
123   SM 12            = SRM, send/receive
123   DECSM 2          = DECANM, ANSI/VT52
123   DECSM 3          = DECCOLM, 132 column
123   DECSM 4          = DECSCLM, scrolling
123   DECSM 8          = DECARM, auto-repeat
12    DECSM 9          = DECINLM, interlace
 23   DECSM 18         = DECPFF, print form feed
 23   DECSM 19         = DECPEX, print extent
 23   DECSM 42         = DECNRCM, national/multinational character
