sub _elem {
    my ($elem_name, $content_fn, $text) = @_;   #! added $text arg
    # an element is represented by the triple [name, attrs, children]
    my $elem = [$elem_name, undef, undef];
    do { local $__frag = $elem;
         $content_fn->();              
         text($text) if defined $text;          #! new line
    };
    push @{$__frag->[2]}, $elem;
}

sub define_vocabulary {
    my ($elems, $attrs) = @_;
    eval "sub $_(&@) { _elem('$_',\@_) }"    for @$elems;  #! proto
    eval "sub ${_}_(\$) { _attr('$_',\@_) }" for @$attrs;
}