How do I type a Chinese dash in XeLaTex

Question

How do I write a Chinese dash, a two-fullwidth-character long dash?

「——」 looks ugly typset with XeLaTex and the font that I am using (The two parts are not connected and there is a gap in the middle). I guess I could use some drawing tool and draw a line at the right hight. But how do I make the line exactly 2 fullwidht characters long?

Answer 1

This depends on the font, If I use SimSun (as I had used it in a previous answer) I see no gap if I use the input you show (2 em dashes) I do see a gap if I use the classic TeX input ------ Unicode 6.1 introduces U+2E3A (TWO-EM DASH) but that might be a bit new to be in commonly distributed fonts, I get no visible character in that slot). Sorry about the probably out of context characters: I borrowed them from the previous question, just to check I had loaded a CJK font correctly.

\documentclass[nofonts]{ctexbook}
\setCJKmainfont{SimSun}


\begin{document}

本条------本条

本条——本条

本条⸺本条

\end{document}

Answer 2

I solved it by creating a new macro that "draws" the dash I want.

\usepackage{calc}
\newcommand{\chinesedash}{\rule[.7ex]{\widthof{二字}}{0.5pt}}