What’s new in babel 26.16

Draft

Option mathdigits

Sometimes using native digits inside math mode comes in handy. With this option, it is now possible to do so without resorting to additional packages. Something like \babelprovide[mathdigits]{hindi} means a digit from the script used by Hindi (i.e., Devanagari) will be rendered using the font for that language (this behavior is similar to that of onchar).

These are true math symbols belonging to the ‘ordinary’ category. This contrasts with Western digits, which belong to the ‘variable’ category (so that \mathit prints italic numbers). However, many scripts lack true italics, and supporting variable digits would require combining fonts and math families, too. (This does not preclude extending the feature to other variants in the future, though doing so would require unicode-math.)

By default, digits are assigned globally to the ‘normal font’ for the corresponding language (applied \AtBeginDocument). An optional value can be passed to assign a different family; for example, \babelprovide[mathdigits=sf]{uyghur}. Note no conversion is done: to use native digits you have to write them explicitly, while Western digits are kept.

Here is an example:

\documentclass{article}

\usepackage[english]{babel}

\babelprovide[import, mathdigits]{thai}
\babelfont[thai]{rm}{Norasi}

\babelprovide[import, mathdigits]{arabic}
\babelfont[arabic]{rm}{Amiri}

\babelprovide[import, mathdigits=sf]{chinese}
\babelfont[chinese]{sf}{FandolHei}

\begin{document}

\begin{array}{c}
45^2 + 17^3 = 6938\\
๔๕^๒ + ๑๗^๓ = ๖๙๓๘\\
٤٥^٢ + ١٧^٣ = ٦٩٣٨\\
四五^二 + 一七^三 = 六九三八
\end{array}

\end{document}