problem on the parentheses direction in equations

Question

I recently installed a MacTex version and I faced a problem with the direction of parentheses both in the enumeration and the text reference using \eqref. I use XeLaTeX to compile the tex files. Since in my tex file I have right-to-left content, I have to use the bidi package.

Example:

Precision is computed as in equation )3.3(.

Here is the code:

\documentclass[oneside, a4paper]{report}

\usepackage{amsmath}

\usepackage{fontspec}\newfontfamily\Farsifont[Script=Arabic]{XB Niloofar}
\usepackage{fontspec}\newfontfamily\Parsifont[Script=Arabic]{XB Kayhan}
\usepackage{bidi}
\newcommand{\ARL}[1]{\RL{\Farsifont #1}}
\newcommand{\PRL}[1]{\RL{\Parsifont #1}}

\begin{document}

Precision is computed as in equation \eqref{eq:precision}.

\begin{equation}
\label{eq:precision}
P = \frac{Number~of~Correct~Constituents}{Total~Number~of~Constituents~in~Parser~Output}
\end{equation}

\end{document}

How can the parentheses be reordered in the correct format?

Answer 1

The main problem here is essentially the same as that in amsmath - bidi - siunitx possible bug? and Joseph Wrights solution there works here too. Additionally, you setting of the text in mathematics, in particular with ~, is not correct, producing error messages. Normally I would write such text chunks in \text, but in this situation you might choose the solution below with \mathit and space written as \:

\documentclass[oneside, a4paper]{report}

\usepackage{amsmath}

\usepackage{fontspec}
\usepackage{bidi}
\newcommand{\ARL}[1]{\RL{\Farsifont #1}}
\newcommand{\PRL}[1]{\RL{\Parsifont #1}}

\csname @Latintrue\endcsname

\begin{document}

Precision is computed as in equation \eqref{eq:precision}.

\begin{equation}
\label{eq:precision}
P = \frac{\mathit{Number\ of\ Correct\ Constituents}}{\mathit{Total\
Number\ of\ Constituents\ in\ Parser\ Output}}
\end{equation}

\end{document}