HEVEA distribution includes .hva packages that are implementations of LATEX packages. Packages described in the “Blue Book” (makeidx, ifthen, graphics —and graphicx!—, color, alltt) are provided. Additionally, quite a few extra packages are provided. I provide no full documentation for these packages, users should refer to the first pages of the package documentation, which can usually be found in the book [LATEX-bis], in your local LATEX installation or in a TeX CTAN-archive.
At the moment, most package options are ignored, except for the babel package, where it is essential.
HEVEA amsmath package defines some of the constructs of the
amsmath package. At the moment, supported constructs are
the cases environment and matrix
environments [LATEX-bis, Section 8.4], the
environments for multi-line displayed
equations (gather,
split,…) [LATEX-bis, Section 8.5] and the
\numberwithin command [LATEX-bis, Section 8.6.2].
HEVEA provides support for the amssymb symbols using
Unicode. I found Unicode equivalent for most symbols. However, a few symbols
remain undefined (e.g. \varsubsetneqq).
The array
package is described in
[LATEX-bis, Section 5.3] and in the local documentation of modern LATEX
installations.
It is a compatible extension of LATEX arrays (see B.10.2).
Basically, it provides new column specifications
and a \newcolumntype construct for user-defined column
specifications.
Table 1 gives a summary of the new column
specifications and of how HEVEA
implements them.
m{width}Equivalent to the pcolumn specification (the width argument is ignored, entries are typeset in paragraph mode with paragraph breaks being reduced to a single line break), except that the entries are centered vertically.b{width}Equivalent to the pcolumn specification, except that the entries are bottom-aligned vertically.>{decl}Can be used before l,c,r,p{…},m{…}orb{…}. It inserts decl in front of the entries in the corresponding column.<{decl}Can be used after l,c,r,p{…},m{…}orb{…}. It inserts decl after entries in the corresponding column.!{decl}Equivalent to @{decl}
Note that centered, top-aligned or bottom-aligned
in the vertical direction, do not
have exactly the same meaning in LATEX and in html. However, the
aspect is the same when all columns agree w.r.t. vertical alignment.
Ordinary column types (c, l and r)
do not specify vertical alignment, which therefore becomes browser
dependent.
The >{decl} and <{decl}
constructs permit the encoding of TEX \cases macro as follows:
\def\cases#1{\left\{\begin{array}{l>{$}l<{$}}#1\end{array}\right.}
(This is an excerpt of the latexcommon.hva file.)
New column specifications are defined by the \newcolumntype
construct:
\newcolumntype{col}[narg]{body}
Where col is one letter, the optional narg is a
number (defaults to 0), and body is built up with
valid column specifications and macro-argument references
(#int).
Examples are:
\newcolumntype{C}{>{\bf}c}
\newcolumntype{E}[1]{*{#1}{c}}
\begin{tabular}{CE{3}}\hline
one & two & three & four \\
five & six & seven & eight \\ \hline
\end{tabular}
The column specification
C means that entries will be typeset centered and using bold
font, while the column specifications E{num}
stands for num centered columns. We get:
| one | two | three | four |
| five | six | seven | eight |
HEVEA implements column specifications with commands defined in the
\newcommand style. Thus, they have the same behaviour as regards
double definition, which is not performed and induces a warning
message.
Thus, a column specification that is
first defined in a macro.hva specific
file, overrides the document definition.
The tabularx
package [LATEX-bis, Section 5.3.5] provides a new tabular
environment tabularx and a new column type X. HEVEA
makes the former equivalent to tabular and the latter
equivalent to p{ignored}. By contrast with the
subtle array formatting that the tabularx package performs,
this may seem a crude implementation. However, rendering is usually
correct, although different.
More generally and from the html point of view such sophisticated formatting is browser job in the first place. However, the html definition allows suggested widths or heights for table entries and table themselves. From HEVEA point of view, drawing the border line between what can be specified and what can be left to the browser is not obvious at all. At the moment HEVEA choice is not to specify too much (in particular, all length arguments, either to column specifications or to the arrays themselves, are ignored). As a consequence, the final, browser viewed, aspect of arrays will usually be different from their printed aspect.
The calc
package enables using traditional, infix, notation for
arithmetic operations
inside the num argument to the
\setcounter{name}{num}
and \addtocounter{name}{num}
constructs (see [LATEX-bis, Section A.4])
The calc package provides a similar extension of the syntax
of the len argument to the \setlength and
\addtolength constructs.
HEVEA does not implement this extension, since it does not
implement length registers in the first place.
The inputenc
package enables LATEX to process a file
according to various 8 bits encodings, plus UTF-8.
The one used encoding is specified as an option while loading the package
\usepackage[encoding]{inputenc}.
At the moment, HEVEA recognises ten latin encodings
(from latin1 to latin10),
the koi8-r encoding,
the ascii encoding,
four windows encodings, the applemac encoding, and the
utf8 encoding.
It is important to notice that loading the inputenc package
alters the html document charset.
For instance if the latin9 input encoding is selected by:
\usepackage[latin9]{inputenc}
Then, the document charset is ISO-8859-15, which is an
enhanced version of ISO-8859-1 with some characters
for Œ, œ and €.
The rationale behind changing the output document charset at the same
time as changing the input encoding is to allow
non-ascii bytes in the input file to be replicated as
themselves in the output file.
However, one can change the document charset (and the output
translator) by using the internal command \@def@charset.
For instance, one can specify latin1 encoding, while
producing html pages in ascii:
\usepackage[latin1]{inputenc}
%HEVEA\@def@charset{US-ASCII}
See section 8.6 for a more thorough description of html charset management.
The inputenc package also provides the
command \inputcoding{encoding} that
changes the input encoding at any time.
The argument encoding can be any of the options accepted
by \usepackage[encoding]{inputenc}.
The command \inputcoding of HEVEA
follows the behaviour of its LATEX counterpart, it the sense
that it obeys scope rules.
Notice that \inputcoding does not change the document output
encoding and charset.
HEVEA implements the following packages: latexsym amssymb, textcomp (a.k.a. “Text companion”) and eurosym (a nice € symbol in LATEX).
The comment package provides two commands,
\excludecomment and \includecomment, for (re-)defining
new environments that ignore their content or that do nothing. The
comment environment is also defined as an environment of the first
kind.
HEVEA supports several simultaneous indexes, following the scheme of the index package, which is present in modern LATEX distributions. This scheme is backward compatible with the standard indexing scheme of LATEX.
Support is not complete, but the most useful commands are available. More precisely, HEVEA knows the following commands:
\renewindex commands that takes the same arguments and that can be
used to redefine previously declared indexes.
\newindex{default}{idx}{ind}{Index}.
\index command except that the information
extracted from arg goes to the tag index.
The tag argument defaults to default, thereby yielding
standard LATEX behaviour for the \index command without an
optional argument.
There also exists a stared-variant \index* that Additionally
typesets arg.
default.
The multind package is supported to some extend, but index is definitely to be preferred.
LATEX version of natbib is present in modern installations.
Implementation is quite complete and compatible
with version 8.0 of the natbib package
(with the keyval style command \setcitestyle).
Unimplemented features are the sorting and compression of references. Automatic generation of an index of citations is handled, but the current implementation probably is quite fragile.
HEVEA provides a slightly incomplete implementation of the
multibib package. The one non-implemented feature is the
simultaneous definition of more than one bibliography.
That is one cannot invoke \newcites as follows:
\newcites{suf1, suf2}{Title1, Title2}
Instead, one should perform to calls to the \newcites command:
\newcites{suf1}{Title1}\newcites{suf2}{Title2}
A basic implementation is provided. At the moment, you can
define one bibliography per included file and no toplevel
bibliography.
HEVEA implementation of this package recognises the option
sectionbib and provides the command \sectionbib
to change the sectioning command introduced by bibliographies.
HEVEA offers support for the LATEX package babel. When it reads the command
\usepackage[lang-list]{babel}
it loads babel.hva, and sends it the saved lang-list. The file babel.hva then looks at each language (say x) in it, and loads x.hva, which offers support for the language x. As in LATEX, the last language in the list is selected as default. As an example the command
\usepackage[english,french,german]{babel}
would load babel.hva, then the files english.hva,french.hva,german.hva containing the respective definitions, and finally activate the definitions in german.hva and sets the current language to german.
The following babel commands for changing and querying the language work as in LATEX :
\selectlanguage : to change the language
\iflanguage : to branch after comparing with current language
The language specific details are described in the corresponding
.hva file, just as in the .sty file for LATEX. Users
need to supply this file for their language, or modify/check the files
if they are already supplied with the distribution. The list of
languages is given below.
| american | austrian | brazil | catalan |
| check | croatian | danish | dutch |
| english | esperanto | finnish | french |
| galician | german | italian | magyar |
| norsk | nynorsk | polish | portuguese |
| romanian | russian | slovak | slovene |
| spanish | swedish | turkish |
The languages for which .hva files are available with the distribution are english, french, german, austrian, czech and portuguese. These may need to be modified as not all accents and hyphenation techniques are supported.
They can be written/modified as simple TEX files (see the section B.16.1.1 on writing TEX macros for details). As an example, one may also take a look at the file french.hva, which describes the details for french.
Note how all definitions are inside the definition for
\french@babel, which is the command that
\selectlanguage{french} would call. Similar commands need to be
provided (i.e. \x@babel in \x.hva for language
x).
Notice that it is wise to write the \x.hva in plain ascii only.
Some definitions may involve specifying Unicode characters, for doing
so, using the \@print@u is recommended (cf. Section 8.3).
The definition of Unicode characters can be found at
http://www.unicode.org/charts/.
Most language specific Unicode characters can be found in the first
few files.
LATEX source.
This package in fact provides a enhanced \verb command that
can appear inside other command arguments.
This command is named \url,
but it can be used for any verbatim text, including DOS-like path
names.
Hence, one can insert urls in one’s document without worrying about
LATEX active characters:
This is a complicated url: \url{http://foo.com/~user#label%coucou}.
which gets typeset as: “This is a complicated url: http://foo.com/~user#label%coucou.”
The main use for the \url command is to specify urls as arguments to
HEVEA commands for hyperlinks (see section 8.1.1):
\hevea{} home page is
\ahrefurl{\url{http://hevea.inria.fr/}}
It yields: “HEVEA home page is http://hevea.inria.fr/”.
However the \url command is fragile, as a consequence it
cannot be used inside \footahref first argument (This is a
LATEX problem, not an HEVEA one).
The url package solves this problem by providing the
\urldef command
for defining commands whose body is typeset by using \url:
\urldef{\heveahome}{\url}{http://hevea.inria.fr/}
Such a source defines the robust command \heveahome as the
intended url.
Hence the following source works as expected:
Have a look at \footahref{\heveahome}{\hevea{} home page}
It yields: “Have a look at HEVEA home page”.
Using \url inside command definitions with a
#i argument is a bad idea, since
it gives “verbatim” a rather random meaning.
Unfortunately, in some situations (e.g, no %, no #),
it may work in LATEX. By
contrast, it does not work in HEVEA. In such situations,
\urldef should be used.
HEVEA implementation is somehow compatible at the “programming level”.
Thus, users can define new commands whose argument is understood
verbatim. The urlhref.hva style file
from the distribution
takes advantage of this to define the \url command, so that it both
typesets an url and inserts a link to it.
\input{urlhref.hva}
Have a look at \url{http://hevea.inria.fr/}
It yields “Have a look at http://hevea.inria.fr/”.
The urlhref.hva
style file (which is an HEVEA style file and not a LATEX
style file) can be adequate for bibliographic references,
which often use \url for its typesetting power.
Of course, loading urlhref.hva only makes sense when
all arguments to \url are urls…
These two packages provide new commands and environments for processing verbatim text. I recommend using moreverb rather than verbatim, since HEVEA implementation is more advanced for the former package.
I strongly recommend the listings package. Learning the user interface requires a little effort, but it is worth it.
HEVEA features a quite compatible implementation, please refer to the original package documentation. Do not hesitate to report discrepancies. Note that HEVEA does not produce very compact html in case you use this package. This can be cured by giving hevea the command-line option -O (see C.1.1.4).
The lstlisting environment is styled through
an homonymous style class (see 9.2 and 9.3) and
most lstlisting environments get translated to div
elements with the appropriate \getenvclass{lstlisting} class,
which, by default is lstlisting.
A few points deserve mention:
font-family:monospace; and white-space:pre;, which, more or less,
specify non-proportional font and mandatory line breaks.
In case you replace lstlisting by another style class (by
\setenvclass{lstlisting}{another one}), your
alternate definition should probably feature an identical
specification. Otherwise, rendering would be poor, as regards spacing
and line breaks.
Here is how specific listings are styled.
We first define a new environment to typeset programs written in the C
language, by using the command \lstnewenvironment:
\lstdefinestyle{colors}{keywordstyle={\bf\color{blue}}, commentstyle={\em\color{magenta}}}
\lstnewenvironment{clisting}
{\setenvclass{lstlisting}{clisting}\lstset{language=C, style=colors}}
{}
The command
\lstnewenvironment{name}{starting
code}{ending code} is from the
listings package, with similar semantics.
In the starting code above, the fragment
\setenvclass{lstlisting}{clisting} instructs HEVEA to
use the style class clisting locally (notice that it could just
be another name). The style class clisting is defined in
the document preamble as follows:
\newstyle{.clisting}{font-family:monospace;white-space:pre;
border-left:solid black;padding-left:2ex;margin-left:2ex;}
Typesetting a C listing with a black border on the left is then as
simple as:
\begin{clisting}
/* Compute, guess what! */
int fact(int n) {
int r = 1 ;
for ( ; n > 0 ; n--) {
r *= n ;
}
return r ;
}
\end{clisting}
The final result is:
div
elements.
Instead they get translated to one cell tables whose td
and table elements
are styled through style classes lstlisting and
lstframe, respectively. Of course, those two style classes
follow the usual \setenvclass/\getenvclass mechanism.
That way, one can for instance center all framed listings by issuing
the following declaration in the document preamble:
\newstyle{.lstframe}{margin:auto;}
Notice that the default style class lstframe is empty.white-space:pre; style declaration is still a
bit young, and some browsers implement it in rather incomplete
fashion. This is particularly true as regards text copy-pasted from
browser display. In case you want to provide your readers with easy
copy-paste of listings, you can, by issuing the command
\lstavoidwhitepre in the document preamble. Then,
white-space:pre; is not used any longer: spaces get rendered
by non-breaking space entities and line-breaks by <BR> elements,
which significantly increase output size. However, as a positive
consequence, display remains correct and text copy-pasted from browser
display indeed possesses the line-breaks shown in display.
LATEX source for the longtable and supertabular packages.
Those two packages provide LATEX users with the possibility to typeset tabular material over several pages [LATEX-bis, Section 5.4]. Of course, HEVEA does not care much about physical pages. Thus the supertabular and longtable environments are rendered more or less as tabular environments inside table environments.
The mathpartir package, authored by D. Rémy, essentially provides two features:
\inferrule (and its starred variant) for
typesetting inferences rules.
We give a short description, focussing on HEVEA-related details. Users are encouraged to refer to the original documentation of the package.
In the following, comments on rule typesetting apply to HEVEA output and not to LATEX output.
In its LATEX version, the mathpar environment is a “paragraph mode for formulas”. It allows to typeset long list of formulas putting as many as possible on the same line:
\begin{mathpar}
A-Formula \and
Longer-Formula \and
And \and The-Last-One
\end{mathpar} |
|
In the example above, formulas are separated with \and. The
LATEX implementation also changes the meaning of paragraph breaks
(either explicit as a \par command or implicit as a blank line)
to act as \and. It also redefines the command \\ as
an explicit line-break in the flow of formulas.
\begin{mathpar}
\int_0^2 xdx = \frac{3}{2}
\\
\int_0^3 xdx = \frac{5}{2}
\end{mathpar} |
|
The HEVEA version is simplistic:
Formulas are typeset in math display
mode,
\and separators always produce horizontal space, while
\\ always produce line-breaks.
However, when prefixed by \hva the meaning of explicit
separators is reversed: that is,
\hva\and produces a line-break, while \hva\\
produces horizontal space.
Hence, we can typeset the previous example on two lines:
\begin{mathpar}
A-Formula \and
Longer-Formula \hva\and
And \and The-Last-One
\end{mathpar} |
|
It is to be noticed that the LATEX version of the package defines
\hva as a no-op, so as to allow explicit instructions given to
HEVEA not to impact on the automatic typesetting performed by LATEX.
The \inferrule macro is designed to typeset inference rules. It
should only be used in math mode (or display math mode). It takes
three arguments, the first being optional, specifying the label,
premises, and conclusions respectively. The premises and the
conclusions are both lists of formulas, and are separated by
\\.
A simple example of its use is
\inferrule
[label]
{one \\ two \\ three \\ or \\ more \\ premises}
{and \\ any \\ number \\ of \\ conclusions \\ as \\ well}
which gives the following rendering:
|
Again, HEVEA is simplistic. Where LATEX performs
actual typesetting, interpreting \\ as horizontal or
vertical breaks, HEVEA always interpret \\ as an
horizontal break. In fact HEVEA interpret all separators
(\\, \and) as horizontal breaks, when
they appear in the arguments of the \inferrule command.
Nevertheless prefixing separators with \hva yields vertical
breaks:
\inferrule
{aa \hva\\ bb}
{dd \\ ee \\ ff} |
|
The color of the horizontal rule that separates the premises and
conclusions can be changed by redefining the command
\mpr@hhline@color. This color must be specified as a low-level
color (cf. Section B.14.2.2).
By default, lines are centered in inference rules. However, this can be changed either by using \mprset{flushleft} or \mprset{center}, as shown below.
$$\mprset{flushleft}
\inferrule
{a \\ bbb \hva\\ ccc \\ dddd}
{e \\ ff \hva\\ gg}
$$ |
|
The mathpartir package provides a starred variant
\inferrule*. In LATEX, the boxes
produced by \inferrule and \inferrule* differ as regards
their baseline, the second being well adapted to derivation trees.
All this is irrelevant to HEVEA,
but \inferrule* remains of interest because of its interface:
the optional argument to the \inferrule* command is a list of
key=value pairs in the style of
keyval.
This makes the variant command much more flexible.
|
Additionally, the value-less key center centers premises and
conclusions (this is
the default), while flushleft commands left alignment of
premises and conclusions (as \mprset{flushleft} does).
Other keys defined by the LATEX package exist and are parsed, but
they perform no operation.
As an example, the code
produces the following output:
|
|
This package should be present in modern latex installations. Basically, the package defines a boolean register pdf, whose value is true for tools that produce PDF (such as pdflatex) and false for tools that produce DVI (such as latex).
The hevea version of the package simply defines the boolean
register pdf with initial value true. Command-line option
-pdf is also added to imagen command-line
options (by using the command \@addimagenopt, see
Section 10.7). As a result, imagen will
normally call pdflatex in place of latex.
In case standard latex processing in imagen is
wished, one can issue the command \pdffalse after loading the
ifpdf package and before \begin{document}. Then, no
command line option is added.
Hence, to achieve latex processing of the image
file, while still loading the ifpdf package, one writes:
\usepackage{ifpdf}
%HEVEA\pdffalse
HEVEA features an implementation of Andrew Seagar’s technique for Thai in LATEX, by the means of the package thai.hva in the distribution.
As regards input encoding, Thai users of HEVEA could (perhaps) use
\usepackage[utf8]{inputenc}.
However, the typesetting of Thai is more subtle than just proper
characters. For that reason, Thai in LATEX is better performed by
another technique, which HEVEA supports. See this specific
document.
The hanging package is implemented. HEVEA implementation consists of no-ops, except for the hangparas environment, which is partially implemented. Assume the following usage of hangparas:
\begin{hangparas}{wd}{n}
…\end{hangparas}
where wd is a length that makes sense both for LATEX and CSS (typically 2ex). Then html output will reproduce LATEX output for n=1, regardless of the given value of argument n. That is, in any paragraph inside the environment, all lines except the first get indented by wd.
The cleveref package
attempts (and mostly succeeds) typesetting references
cleverly. Its main feature is a \cref command that accepts several,
comma separated, label references and typesets them as a list
(which can be one-element long, of course) prefixed with sectional unit names.
The HEVEA implementation is quite complete, but it does not support some
of the subtleties of the LATEX implementations, especially as regards
customisation.
The fancyverb and colortbl packages are partly implemented.
The xspace package is implemented, in simple cases, rendering is satisfactory, but beware: HEVEA differs significantly from TEX, and discrepancies are likely.
The chngcntr package is implemented. This package provides commands to connect (and disconnect) counters once they are created (see http://www.tex.ac.uk/cgi-bin/texfaq2html?label=addtoreset).
The import package is partially implemented: all starred commands are missing.
The booktabs package is implemented. This package provides nicer rulers in tables as specific commands. HEVEA defines those as no-ops.