Adding section or subsection to every reference (but not label)

In the form topic, "Full context variable depth references to list labels?," someone wanted to force LaTeX to

• use legal-format lists
• reformat its references to prefix them with the full subsection number (e.g., "2.1-") when inside a subsection and section number (e.g., "2-") otherwise.

I suggested:

\usepackage{enumitem}
\newlist{legal}{enumerate}{10}
\makeatletter
\setlist[legal]{label*=\arabic*.,
                ref=\csname 
                    the\enit@prevlabel
                    \endcsname\arabic*.}
\newcommand\thesectionlabel{%
        \ifnum\value{subsection}=0 
                \thesection
        \else
                \thesubsection
        \fi}
\newcommand{\thelegal}{\thesectionlabel-}
\makeatother

\usepackage{varioref}
\labelformat{equation}%
        {\thesectionlabel-\textup{(#1)}}
\labelformat{figure}{\thesectionlabel-#1}
\labelformat{table}{\thesectionlabel-#1}

I've wrapped lines (by inserting VERY important % characters in special places to make the snippet viewable in this thin blog. As you can see in the original thread, my suggestion looked shorter because the lines were unwrapped.

It seems to work well and is one of those solutions that TeXnicians would probably do on their own without a second thought and would never document, but it's something complicated-enough that everyone else would tear their hair out searching for it.