\Header{Session}{Deprecated:  Session Data and Debugging Tools}
\alias{browseAll}{Session}
\alias{sessionData}{Session}
\alias{traceOff}{Session}
\alias{traceOn}{Session}
\keyword{internal}{Session}
\begin{Description}\relax
The functions \code{traceOn} and \code{traceOff} have been replaced by
extended versions of the functions \code{\Link{trace}} and
\code{\Link{untrace}}, and should not be used.
\end{Description}
\begin{Usage}
\begin{verbatim}
sessionData()

traceOn(what, tracer=browseAll, exit=NULL)

traceOff(what)

browseAll()

\end{verbatim}
\end{Usage}
\begin{Details}\relax
\describe{
\item[\code{sessionData}:] return the index of the session data in the search list,
attaching it if it is not attached.


\item[\code{traceOn}:] initialize tracing on calls to function \code{what}.  The function
or expression \code{tracer} is called on entry, and the function
or expression \code{exit} on exit.


\item[\code{traceOff}:] turn off tracing of this function.


\item[\code{browseAll}:] browse the current stack of function calls.

Uses the function \code{debugger} to set up browser calls on the
frames.  On exit from that function, computation continues after
the call to \code{browseAll}.  Computations done in the frames
will have no effect.

}
\end{Details}
\begin{References}\relax
See \emph{Programming with Data} (John M. Chambers, Springer, 1998)
for the equivalent functions.
\end{References}

