define-command -docstring %{
    Format selection with shfmt -p, keeping whitespace prefix.
} \
shfmt %{
    evaluate-commands -save-regs | %{
        set-register | %{
            input=$(cat)
            prefix=$(printf '%s\n' "$input" | head -n1 | grep -o '^[[:space:]]*')
            printf '%s\n' "$input" | \
            	perl -pe "s/^\Q$prefix\E//" | \
            	shfmt -p | \
            	sed "s/^/$prefix/"
	}
        execute-keys '|<ret>'
    }
}

define-command -hidden sh-object-outer %~
    execute-keys '<a-/>%sh[{([<lt>]<ret>M'
~

define-command -hidden sh-object-inner %{
    execute-keys ':sh-object-outer<ret><a-:>K<a-;>Jx<a-:>'
}

define-command -docstring 'format %sh blocks in kakscript' sh-kak-shfmt %{
    execute-keys -itersel -draft '<a-i><a-;>sh-object-wrap<ret>:shfmt<ret>'
}

map global object <a-s> '<a-;>sh-object-wrap<ret>' -docstring 'shell block'
try %{ declare-user-mode kak }
map global kak = ':sh-kak-shfmt<ret>' -docstring 'format current sh block'