define-command \
-docstring %{
    Replace the selections with the date, with the args passed as a
    string to date -d.
} \
insert-date -params 0.. %{
    evaluate-commands -draft -save-regs '|"' %{
        set-register | "date -d '%arg{@}' '+%%Y-%%m-%%d' | tr -d '\n'"
        echo -debug "Inserting date: %reg{pipe}"
        # we delete the trailing newline
        execute-keys '|<ret>'
    }
}

alias global date insert-date

define-command -params 2 \
-docstring %{
    Swap all occurence of param A with param B in selections.
} \
sedswap %{
    evaluate-commands -save-regs | %{
        set-register | %exp{
            sed "s/%arg{1}/__FOOTOKEN__/; \
            s/%arg{2}/%arg{1}/; s/__FOOTOKEN__/%arg{2}/"
        }
        execute-keys '|<ret>'
    }
}