zsh + tmux + fzf + rg - autocomplete words in command

pane.sh

function _print_all_panes() {
  for pane_id in $(tmux list-panes -F '#{pane_id}'); do
    tmux capture-pane -p -J -S 0 -E - -t "$pane_id" | tr ' ' '\n' | sort -u | rg '[a-zA-Z0-9]+'
  done
}

_tmux_pane_words() {
  local current_word="${LBUFFER##* }"
  local new_rbuffer="${RBUFFER/#[^ ]##/}"
  local prompt="${LBUFFER% *} ␣ $new_rbuffer "

  local selected_word=$(_print_all_panes | fzf --query="$current_word" --prompt="$prompt" --height=20 --layout=reverse --no-sort --print-query | tail -n1)
  local new_lbuffer="${LBUFFER% *} $selected_word"
  BUFFER="$new_lbuffer$new_rbuffer"
  CURSOR="${#${new_lbuffer}}"

  zle redisplay
}

zle -N _tmux_pane_words
bindkey '^U' _tmux_pane_words