Zsh zle shift selection

How to use shift to select part of the commandline (like in many text editors) ?

shift-arrow() {
  ((REGION_ACTIVE)) || zle set-mark-command
  zle $1
}
shift-left()  shift-arrow backward-char
shift-right() shift-arrow forward-char
shift-up()    shift-arrow up-line-or-history
shift-down()  shift-arrow down-line-or-history
zle -N shift-left
zle -N shift-right
zle -N shift-up
zle -N shift-down

bindkey $terminfo[kLFT] shift-left
bindkey $terminfo[kRIT] shift-right
bindkey $terminfo[kri]  shift-up
bindkey $terminfo[kind] shift-down

That assumes your terminal sends a different escape sequence upon Shift-Arrows from the one sent upon Arrow and that your terminfo database is properly populated with corresponding kLFT and kRIT capabilities, and that you're using emacs style key binding.

Or, to factorize the code a bit:

shift-arrow() {
  ((REGION_ACTIVE)) || zle set-mark-command
  zle $1
}
for key  kcap seq        widget (
    left  LFT $'\e[1;2D' backward-char
    right RIT $'\e[1;2C' forward-char
    up    ri  $'\e[1;2A' up-line-or-history
    down  ind $'\e[1;2B' down-line-or-history
  ) {
  functions[shift-$key]="shift-arrow $widget"
  zle -N shift-$key
  bindkey ${terminfo[k$kcap]-$seq} shift-$key
}

Above, hardcoded sequences for cases where the terminfo database doesn't have the information (using xterm sequences).