babel is not aware of \if@nonlatin conditional from bidi

[Udi-Fogiel]

bidi use a separate conditional from \if@RTL called \if@nonlatin in several places in its code, this conditional is not set by \RL, \setRL etc., so babel need to set this conditional according to the script (see section 4.4 of bidi's manual).

The places I'm aware it is used are in equation tags (in amsmath and mathtools) to correct the parenthesis, see [1] and [2], in breqn (not sure for what), in \text from amsmath to correct the direction of the text, see [3], and in a code it inserts between numbers and dots and dashes via \XeTeXinterchartoks, see [4], which I guess suppose to correct the order in arabic, but is wrong for hebrew and other languages (so it should be disabled sometimes).

Here is a code to demonstrate the problem with \text and tagged equations

\documentclass{article}

\usepackage{amsmath}
\usepackage[hebrew,provide=*,bidi=bidi-r]{babel}
\babelfont{rm}{David CLM}

\begin{document}
%\makeatletter\@nonlatintrue
\begin{equation}
1+2=3
\end{equation}

$\text{שלום עולם!}$
\end{document}

And this is a code to demonstrate the problem with the code that bidi inserts via \XeTeXinterchartoks

\documentclass{article}

\usepackage[hebrew,provide=*,bidi=bidi-r]{babel}
\babelfont{rm}{David CLM}

\begin{document}
\makeatletter\@nonlatintrue
1-2
\end{document}

[jbezos]

Interestingly, \setlatin and \setnonlatin are not documented (but they are defined). Certainly bidi is about ‘Arabic bidi’ and I’m not sure the order must be fixed in babel or in bidi. I'm thinking about it.

[Udi-Fogiel]

I’m not sure the order must be fixed in babel or in bidi. I'm thinking about it.

It always looked odd to me that bidi do that, isn't the script of the font should handle that by Itself?

FWIW, this is what polyglossia do (for several languages).