# Alias '...' to do '../..'
# Example: type 'cd ...' to get 'cd ../..'
rationalise-dot() {
    local MATCH
    if [[ $LBUFFER =~ '(^|/| |  |'$'\n''|\||;|&)\.\.$' ]]; then
        LBUFFER+=/
        zle self-insert
        zle self-insert
    else
        zle self-insert
    fi
}
zle -N rationalise-dot
bindkey . rationalise-dot