align rules to baseline

[teepeemm]

This aligns rules to the baseline, resolving #1995. It also provides default dimensions (otherwise, vrules end up with a width of text-indent). Some other notes:

• hrule should be in vertical mode but isn't. (I think that's the correct terminology: TeX put the hrule on its own line and subsequent text on another line; LaTeXML put everything on the same line.)
• I don't appear to have html.sty, so I'm not sure what html.sty.ltxml is trying to emulate.
• TeX.pool.ltxml claims that hrule and vrule can appear as rules within an alignment/table. I was unable to see this behavior in LaTeXML: all tabular rules were rendered via a ltx:td/@Ltx:border attribute, not a ltx:rule element. Did I overlook some construction that would have resulted in ltx:rule?

The tex code I was using to test this out:

\documentclass{article}
\usepackage[lined]{algorithm2e}
\usepackage{xcolor}
\usepackage{latexml}
\iflatexml\usepackage{html}\fi
\begin{document}
A\rule{1cm}{.4pt}A
B\vrule height 1cm\relax B

C\hrule width 5cm\relax C

D\boxframe{5cm}{.1pt}{1cm}D

\begin{algorithm}[H]
  \If{understand}{go to next section\;}
\end{algorithm}

\iflatexml
E\htmlrule E
F\htmlrule*F
G\HTMLrule G
H\HTMLrule*H
\fi

\end{document}

[brucemiller]

Works a charm; Thanks!

BTW: Yes, the \hrule & '\vrule` in tables are handled specially (and are complicated); basically they disappear into attributes on the table cells, eventually ending up as specific CSS classes.