# Why do you need both list-pair-separator and list-final-separator in siunitx?

I wanted to translate the automatically written words in the siunitx package to Danish (at least the parts I use) and found the answer to Problem with \SIlist with two values and list-final-separator = {, }.

I used the following code to do it:

\documentclass{memoir}
\usepackage[danish]{babel}
\usepackage[range-phrase={ til },
list-final-separator={ og },
list-pair-separator={ og },
detect-all,
separate-uncertainty=true,
group-digits=false]{siunitx}

\begin{document}

\SIlist{8;9;10}{\keV}

\SIlist{8;10}{\keV}

\end{document}


and got the output:

My question is (probably for Joseph Wright): Why do I need to state both pair and final (list separator)? Is it just me who wants the same separator in both cases? I thought (from the name of the option) that final was all I needed and that pair could be used if I wanted them to differ. Wouldn't that be a better option?

• I guess it's for coping with the “Oxford comma”; according to this practice you write “apples and oranges”, but “apples, pears, and oranges”. – egreg May 16 '14 at 14:25
• Also known as serial comma – cgnieder May 16 '14 at 14:26

Depending on the language/editorial style, the 'filler' used in a list of two items:

<item one> <pair separator> <item two>


and the filler used in a longer list:

<item one> <list separator> <item two> <final separator>


may be different (e.g. in English with the 'Oxford comma' the first case is just 'and' but the second case is ',and'). The only way to cover that in an interface is to differential between the two: trying to say 'you can set only one' and have inheritance is asking for trouble!

• Entirely unrelated to TeX, of course! – Joseph Wright May 16 '14 at 14:27
• 'inheritance' was the word I was looking for... So the point is that inheritance is messy, I guess. Also I didn't think of the (Oxford) comma notation since that's not a problem in Danish as far as I'm concerned. Is there another place I should have posted this question (non-TeX forum)? – Thomas May 16 '14 at 16:05