2 Style files

• Standard base styles
• Other base styles
• Other style files

L^AT_EX style files are files that are not intended to produce output, but define document layout parameters, commands, environments, etc.

2.1 Standard base styles

The base style of a L^AT_EX document is the argument to the \documentclass command (\documentstyle in old style). Normally, the base style of a document defines the structure and appearance of the whole document.

H^EV^EA really knows about two L^AT_EX base styles, article and book. Additionally, the report base style is recognized and considered equivalent to book and the seminar base style for making slides is recognized and implemented by small additions on the article style.

Base style style is implemented by an H^EV^EA specific style file style.hva. More precisely, H^EV^EA interprets \documentclass{style} by attempting to load the file style.hva (see section C.1.1.1 on where H^EV^EA searches for files). Thus, at the moment, H^EV^EA distribution includes the files, article.hva, book.hva, etc.

2.2 Other base styles

Documents whose base style is not recognized by H^EV^EA can be processed when the unknown base style is a derivation of a recognized base style.

Let us assume that doc.tex uses an exotic base style such as acmconf. Then, typing hevea doc.tex will yield an error, since H^EV^EA cannot find the acmconf.hva file:

# hevea.opt doc.tex
doc.tex:1: Warning: Cannot find file: acmconf.hva
doc.tex:1: Error while reading LaTeX: No base style
Adios

This situation is avoided by invoking H^EV^EA with the known base style file article.hva as an extra argument:

# hevea article.hva doc.tex

The extra argument instructs H^EV^EA to load its article.hva style file before processing doc.tex. It will then ignore the document base style specified by \documentclass (or \documentstyle).

Observe that the fix above works because the acmconf and article base styles look the same to the document (i.e. they define the same macros). More generally, most base styles that are neither article nor book are in fact variations on either two of them. However, such styles usually provides extra macros. If users documents use these macros, then users should also instruct H^EV^EA about them (see section 4.1).

Finally, it is important to notice that renaming a base style file style.cls into style.hva will not work in general. As a matter of fact, base style files are T_EX and not L^AT_EX source and H^EV^EA will almost surely fail on T_EX-ish input.

2.3 Other style files

A L^AT_EX document usually loads additional style files, by using the commands \input or \usepackage or \input.

2.3.1 Files loaded with \input

Just like L^AT_EX, H^EV^EA reacts to the construct \input{file} by loading the file file. (if I got it right, H^EV^EA even follows T_EX’s crazy conventions on .tex extensions).

As it is often the case, assume that the document doc.tex has a \input{mymacros.tex} instruction in its preamble, where mymacros.tex gathers custom definitions. Hopefully, only a few macros give rise to trouble: macros that performs fine typesetting or T_EXish macros. Such macros need to be rewritten, using basic L^AT_EX constructs (section 4 gives examples of macro-rewriting). The new definitions are best collected in a style file, mymacros.hva for instance. Then, doc.tex is to be translated by issuing the command:

# hevea mymacros.hva doc.tex

The file mymacros.hva is processed before doc.tex (and thus before mymacros.tex). As a consequence of H^EV^EA behaviour with respect to definition and redefinition (see section B.8.1), the macro definitions in mymacros.hva take precedence over the ones in mymacros.tex, provided the document original definitions (the ones in mymacros.tex) are performed by \newcommand (or \newenvironment).

Another situation is when H^EV^EA fails to process a whole style file. Usually, this means that H^EV^EA crashes on that style file. The basic idea is then to write a mymacros.hva style file that contains alternative definitions for all the commands defined in mymacros.sty. Then, H^EV^EA should be instructed to load mymacros.hva and not to load mymacros.tex. This is done by invoking hevea as follows:

# hevea mymacros.hva -e mymacros.tex doc.tex

Of course, mymacros.hva must now contain replacements for all the useful macros of mymacro.tex.

2.3.2 Files loaded with \usepackage

As far as I know, L^AT_EX reacts to the construct \usepackage{name} by loading the file name.sty. H^EV^EA reacts in a similar, but different, manner, by loading the file name.hva.

H^EV^EA distributions already includes quite a few .hva implementations of famous packages (see section B.17). When a given package (say zorglub) is not implemented, the situation may not be as bad as it may seem first. Hopefully, you are only using a few commands from package zorglub, and you feel confident enough to implement them yourself. Then, it suffices to put your definitions in file zorglub.hva and H^EV^EA will react to \usepackage{zorglub} by loading zorglub.hva.

See section B.5.2 for the full story on \usepackage.