Add a shortcut to edit the current buffer in vim

buffer-edit.zsh

_buffer_edit_() {
  # Create tmp file
  local tf="$(mktemp /tmp/zshXXXXXXXX)";
  # Place current buffer in tmp file
  echo $BUFFER > $tf;
  # Open tmp file in vim, and if exits with 0, set buffer to tmp file
  vim $tf && BUFFER="$(cat $tf)";
  # Remove tmp file
  rm $tf;
};
# Create a new zle widget for the buffer edit function
zle -N _buffer_edit _buffer_edit_;
# Bind the buffer edit widget to ^Xe
bindkey '^Xe' '_buffer_edit'