{ lib }:

let
  inherit (builtins) listToAttrs;
  inherit (lib) nameValuePair removePrefix removeSuffix;

  wrap = val: "<${val}>";
  unwrap = val: removePrefix "<" (removeSuffix ">" val);

  char = num: wrap "Char-${num}"; # map a character by its decimal, octal or hexadecimal number
  shift = key: wrap "S-${unwrap key}"; #	shift-key			*shift* *<S-*
  ctrl = key: wrap "C-${unwrap key}"; #		control-key			*control* *ctrl* *<C-*
  meta = key: wrap "M-${unwrap key}"; #	alt-key or meta-key		*META* *ALT* *<M-*
  super = key: wrap "D-${unwrap key}"; # command-key or "super" key	*<D-*

  keys = listToAttrs (map (v: nameValuePair v (wrap v)) (
    [
      "Leader"
      "LocalLeader"
      "Cmd"
      "Plug"
      "MouseMove"

      "Nul"
      "Bs"
      "Tab"
      "NL"
      "CR"
      "Esc"
      "Space"
      "lt"
      "Bslash"
      "Bar"
      "Del"
      "Csi"
      "Eol"
      "Ignore"
      "Nop"
      "Up"
      "Down"
      "Left"
      "Right"
      "Help"
      "Undo"
      "Insert"
      "Home"
      "End"
      "PageUp"
      "PageDown"
      "kUp"
      "kDown"
      "kLeft"
      "kRight"
      "kHome"
      "kEnd"
      "kOrigin"
      "kPageUp"
      "kPageDown"
      "kDel"
      "kPlus"
      "kMinus"
      "kMultiply"
      "kDivide"
      "kPoint"
      "kComma"
      "kEqual"
      "kEnter"
    ]
    ++ map (n: "F${toString n}") (lib.range 1 12)
    ++ map (n: "k${toString n}") (lib.range 0 9)
  )
  );
in
{ inherit char shift ctrl meta super; } // keys // {
  return = keys.cr;
  enter = keys.cr;
  backslash = keys.bslash;

  cmd = expr: keys.Cmd + expr + keys.CR;
  leader = expr: keys.Leader + expr;
  localLeader = expr: keys.LocalLeader + expr;
}