Loading other files

L^ATEX provides the commands || and |for using classes or packages inside other classes or packages. We recommend strongly that you use them, rather than the primitive | =| command, for a number of reasons.

Files loaded with | =<filename>| will not be listed in the || list.

If a package is always loaded with |or | then, even if its loading is requested several times, it will be loaded only once. By contrast, if it is loaded with | =| then it can be loaded more than once; such an extra loading may waste time and memory and it may produce strange results.

If a package provides option-processing then, again, strange results are possible if the package is | =| rather than loaded by means of | or |.

If the package |foo.sty| loads the package |baz.sty| by use of | =baz.sty| then the user will get a warning:

   LaTeX Warning: You have requested package `foo',
                  but the package provides `baz'.

Unfortunately, if you are upgrading the file |myclass.sty| to a class file then you have to make sure that any old files which contain | =myclass.sty| still work.

This is also true of the standard classes (|article|, |book| and |report|), since a lot of existing L^ATEX 2.09 document styles contain | =article.sty|. The approach which we took was to provide minimal files |article.sty|, |book.sty| and |report.sty|, which load the appropriate class files. ;''

;''For example, |article.sty| contains just the following lines:;''

   \NeedsTeXFormat{LaTeX2e}
   \@obsoletefile{article.sty}{article.cls}
   \LoadClass{article}

;''