How to modify the decimal separator of the tasks package?

Question

By default, the decimal separator of the tasks package is the period. In French, it is the comma. How to make the following code display a comma while keeping the period in the source code?

In other words, the following code

\documentclass{article}
\usepackage{tasks}
\usepackage[french]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\begin{document}
\begin{tasks}[item-format=\ensuremath](1)
\task 0.6\times0.7=0.42
\task 0.05\times0.1=0.005
\task 0.07\times0.08=0.0056
\end{tasks}
\end{document}

looks like this:

and not as this:

Fun. If I add \usepackage[spanish]{babel} (and T1 fonts, ça va sans dire), it works. But with [french], it doesn't, maybe there some option... — Rmano, May 26 '23 at 16:52
Not in French with this code \usepackage[french]{babel} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} I updated the question code. — AndréC, May 26 '23 at 16:58
Yes, I know. But if you try spanish you'll have your comma, so there should be some trick done there (I'm looking for it). Hardly compatible with french, I fear... — Rmano, May 26 '23 at 17:04
Would locally forcing the language to Spanish be acceptable ? (I mean, in the item-format) — Rmano, May 26 '23 at 17:12
If there is no other solution, this is a decent way to do it. I will write to the package maintainer to add something that handles this. — AndréC, May 26 '23 at 18:17

score 2 · Answer 1 · answered May 26 '23 at 17:34

When using spanish in babel, the decimal point in math mode numbers is automatically changed to a comma(*). The code doing the magic is in spanish.ldf around line 664, but it's a tad (a very big tad) off the top for me to just leverage it. What you can do is typing the math formulas in Spanish in task items...

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{tasks}
\usepackage[spanish, french]{babel}
\newcommand\badtrick[1]{\foreignlanguage{spanish}{\ensuremath{#1}}}
\begin{document}
\begin{tasks}[item-format=\badtrick](1)
\task 0.6\times0.7=0.42
\task 0.05\times0.1=0.005
\task 0.07\times0.08=0.0056
% added to show the problem with automagically change the decimal mark...
\task a.3\times0.006=0.b
\end{tasks}
\end{document}

(*) I am not so much fond of it (because for example $a.0$ is rendered as a,0; I find cleaner to use \num{} from siunitx for that task.)

How to modify the decimal separator of the tasks package?

1 Answers1