\Header{checkTnF}{Check R Code for T/F}
\alias{print.checkTnF}{checkTnF}
\keyword{utilities}{checkTnF}
\keyword{documentation}{checkTnF}
\begin{Description}\relax
Checks the specified R code for occurrences of \code{T} or \code{F},
and gathers the expression containing these.  This is useful as in R
\code{T} and \code{F} are just variables which are set to the logicals
\code{TRUE} and \code{FALSE} by default, but are not reserved words
and hence can be overwritten by the user.  Hence, one should always
use \code{TRUE} and \code{FALSE} for the logicals.\end{Description}
\begin{Usage}
\begin{verbatim}
checkTnF(package, dir, file, lib.loc = NULL)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{package}] a character string naming an installed package.  If
given, the installed R code of the package is checked.  R code
installed as an image file cannot be checked.
\item[\code{dir}] a character string specifying the path to a package's root
source directory.  This should contain the subdirectory \code{R}
(for R code).  Only used if \code{package} is not given.
\item[\code{file}] the name of a file containing R code to be checked.  Used
if neither \code{package} nor \code{dir} are given.
\item[\code{lib.loc}] a character vector of directory names of \R{} libraries,
or \code{NULL}.  The default value of \code{NULL} corresponds to all
libraries currently known.  The specified library trees are used to
to search for \code{package}.
\end{ldescription}
\end{Arguments}
\begin{Value}
An object of class \code{"checkTnF"} which is a list with the
expressions found to contain \code{T} or \code{F}.

There is a \code{print} method for nicely displaying the information
contained in such objects.\end{Value}
\begin{Section}{Warning}
This function is still experimental.  Both name and interface might
change in future versions.\end{Section}

