# ↑↑↓↓←→←→

arrow:        {west: ←, east: →, north: ↑, south: ↓, horizontal: ↔, vertical: ↕, north_west: ↖, north_east: ↗, south_west: ↙, south_east: ↘,
  stroke:     {west: ↚, east: ↛,                     horizontal: ↮,                                                                        },
  wave:       {west: ↜, east: ↝,                     horizontal: ↭,                                                                        },
  squiggle:   {west: ⇜, east: ⇝                                                                                                            },
  two_headed: {west: ↞, east: ↠, north: ↟, south: ↡                                                                                        },
  tailed:     {west: ↢, east: ↣,                                                                                                           },
  from_bar:   {west: ↤, east: ↦, north: ↥, south: ↧                                                                                        },
  to_bar:     {west: ⇤, east: ⇥, north: ⤒, south: ⤓                                                                                        },
  underbar:   {                                                     vertical: ↨                                                            },
  hook:       {west: ↩, east: ↪,                                                                                                           }, # bad naming
  loop:       {west: ↫, east: ↬                                                                                                            }, # bad naming
  zigzag:     {                            south: ↯                                                                                        }, # bad naming

#↰↱↲↳↴↵
#  ↶↷↸↹↼↽↾↿⇀⇁⇂⇃
#  ⬎
#  ⬏
#  ⬐
#  ⬑

  long:        {west: ⟵, east: ⟶,                     horizontal: ⟷,                                                                        },
    from_bar:  {west: ⟻, east: ⟼                                                                                                            },
    squiggle:  {         east: ⟿                                                                                                            },
    double:    {west: ⟸, east: ⟹,                     horizontal: ⟺,                                                                        },
  double:      {west: ⇐, east: ⇒, north: ⇑, south: ⇓, horizontal: ⇔, vertical: ⇕, north_west: ⇖, north_east: ⇗, south_west: ⇙, south_east: ⇘},
    from_bar:  {west: ⟽, east: ⟾                                                                                                            },
    stroke:    {west: ⇍, east: ⇏,                     horizontal: ⇎,                                                                        },
  triple:      {west: ⇚, east: ⇛, north: ⤊, south: ⤋                                                                                        },
  quadruple:   {west: ⭅, east: ⭆                                                                                                            },
#  harpoon: ⇋⇌
  doubled:     {west: ⇇, east: ⇉, north: ⇈, south: ⇊                                                                                        },
  opposite:
  { clockwise:     {                                  horizontal: ⇄, vertical: ⇅,                                                           },
    anticlockwise: {                                  horizontal: ⇆, vertical: ⇵,                                                           }},
  tripled:     {west: ⬱, east: ⇶,                                                                                                           },
  dash:        {west: ⇠, east: ⇢, north: ⇡, south: ⇣,                                                                                       },
  white:       {west: ⇦, east: ⇨, north: ⇧, south: ⇩, horizontal: ⬄, vertical: ⇳, north_west: ⬁, north_east: ⬀, south_west: ⬃, south_east: ⬂},
  black:       {west: ⬅, east: ⮕, north: ⬆, south: ⬇, horizontal: ⬌, vertical: ⬍, north_west: ⬉, north_east: ⬈, south_west: ⬋, south_east: ⬊},
  open_headed: {west: ⇽, east: ⇾,                     horizontal: ⇿                                                                         },
  stroke:
  { vertical:  {west: ⇷, east: ⇸,                     horizontal: ⇹                                                                         },
    double:    {west: ⇺, east: ⇻,                     horizontal: ⇼                                                                         }},
  clockwise: ↻,
  anticlockwise: ↺,
}