{The wonders of\/ \cs{csname}}
{Amy Hendrickson}
{A surprisingly useful tool, \cs{csname}\ldots\cs{endcsname}, offers
many opportunities for interesting and useful macros, whenever it is
convenient to dynamically generate a series of definitions. When each
definition contains a counter in its name, we can then call the
definition using a loop that advances a counter, and then calling the
definition using the loop counter inside the \cs{csname}\ldots\cs{endcsname}.

A trivial use is for endnotes. More interestingly, csname definitions
can be used to send a set of definitions to the \code{.aux} file, where
each new definition contains the current page number in its name, with a
`security level' number being defined. This allows the dynamic
redefinition of the security level for a particular page, {\it within
the \code{.aux} file} depending on whether the new number is higher or
lower than the previous number. This can be used to determine the
highest security level on any particular page. When the \code{.aux} file
is then input, we can access the csname definition in a running head of
the \LaTeX\ document, calling \cs{csname}\ldots\cs{endcsname} control
sequence and using the current page number within
\cs{csname}\ldots\cs{endcsname}, to activate the definition of the
highest security level on that page, and use the information to print
the security level on top of the page.

Another interesting use is for on-line report generation, where a csname
definition can be used, for instance, to generate hyperlinks for
financial analyses of stocks, in a report that compares hundreds of
stocks, and then be able to automatically build a hyperlinked table of
contents, using tabs built with \TikZ.

Code and examples will be shown for each of these methods and uses of
dynamically generated macros using \cs{csname}\ldots\cs{endcsname}, and
we'll look at some other ways this tool may be used as well.
}