Module: Muxr::KeyParser

Defined in:
lib/muxr/key_parser.rb

Overview

Translates an array of “keys” entries (a mix of literal text and vim-style named keys like “<esc>”) into a stream of byte segments tagged by kind.

Each input element is either:

- Literal text (UTF-8) — emitted as [:literal, bytes].
- A named key wrapped in angle brackets like "<esc>", "<c-c>", "<up>" —
  emitted as [:special, bytes] using the appropriate control sequence.

The tagged form lets callers wrap only literal segments in bracketed-paste markers when desired. Concatenating the bytes of all segments gives the raw byte stream to write to the PTY.

Constant Summary collapse

NAMED_KEY_RE = 
/\A<([^<>]+)>\z/.freeze
CSI =

CSI = ESC [ , SS3 = ESC O — both standard xterm key encodings.

"\e[".b.freeze
SS3 = 
"\eO".b.freeze
NAMED_KEYS =

Single canonical map. Keys are lowercased; aliases live alongside their canonical forms. Values are ASCII byte strings.

{
  "esc"      => "\e".b,
  "escape"   => "\e".b,
  "enter"    => "\r".b,
  "cr"       => "\r".b,
  "return"   => "\r".b,
  "tab"      => "\t".b,
  "s-tab"    => "#{CSI}Z".b,
  "bs"       => "\x7f".b, # what real backspace keys send through a PTY
  "backspace"=> "\x7f".b,
  "space"    => " ".b,
  "up"       => "#{CSI}A".b,
  "down"     => "#{CSI}B".b,
  "right"    => "#{CSI}C".b,
  "left"     => "#{CSI}D".b,
  "home"     => "#{CSI}H".b,
  "end"      => "#{CSI}F".b,
  "pageup"   => "#{CSI}5~".b,
  "pagedown" => "#{CSI}6~".b,
  "f1"       => "#{SS3}P".b,
  "f2"       => "#{SS3}Q".b,
  "f3"       => "#{SS3}R".b,
  "f4"       => "#{SS3}S".b,
  "f5"       => "#{CSI}15~".b,
  "f6"       => "#{CSI}17~".b,
  "f7"       => "#{CSI}18~".b,
  "f8"       => "#{CSI}19~".b,
  "f9"       => "#{CSI}20~".b,
  "f10"      => "#{CSI}21~".b,
  "f11"      => "#{CSI}23~".b,
  "f12"      => "#{CSI}24~".b
}.freeze
CTRL_RE = 
/\Ac-([a-z])\z/.freeze

Class Method Summary collapse

Class Method Details

.classify(entry) ⇒ Object

Raises:



71
72
73
74
75
76
77
78
79
80
 
# File 'lib/muxr/key_parser.rb', line 71

def classify(entry)
  m = NAMED_KEY_RE.match(entry)
  return [:literal, entry.b] unless m

  name = m[1].downcase
  bytes = NAMED_KEYS[name] || ctrl_bytes(name)
  raise Dispatcher::Error.new("unknown named key #{entry.inspect}") unless bytes

  [:special, bytes]
end

.ctrl_bytes(name) ⇒ Object 



82
83
84
85
86
87
 
# File 'lib/muxr/key_parser.rb', line 82

def ctrl_bytes(name)
  m = CTRL_RE.match(name)
  return nil unless m
  # <c-a>=0x01 .. <c-z>=0x1A
  (m[1].ord - "a".ord + 1).chr.b
end

.translate(entries) ⇒ Object

Returns an array of [kind, bytes] pairs. Raises Dispatcher::Error on a non-array input or an unrecognized ‘<name>`.

Raises:



62
63
64
65
66
67
68
69
 
# File 'lib/muxr/key_parser.rb', line 62

def translate(entries)
  raise Dispatcher::Error.new("`keys` must be an array of strings") unless entries.is_a?(Array)

  entries.map do |entry|
    raise Dispatcher::Error.new("`keys` entries must be strings") unless entry.is_a?(String)
    classify(entry)
  end
end