\HeaderA{validMsg}{Conditionally append result to validity message}{validMsg}
\keyword{utilities}{validMsg}
\begin{Description}\relax
This function facilitates constructing messages during S4 class
validation, and is meant for developer rather than end-user use.
\end{Description}
\begin{Usage}
\begin{verbatim}
validMsg(msg, result)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{msg}] A character vector or NULL.
\item[\code{result}] Any vector.
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
This function appends \code{result} to \code{msg}, but only if
\code{result} is a character vector.
\end{Details}
\begin{Author}\relax
Martin Morgan <mtmorgan@fhcrc.org>
\end{Author}
\begin{Examples}
\begin{ExampleCode}
msg <- NULL
validMsg(msg, FALSE) # still NULL
msg <- validMsg(msg, "one")
validMsg(msg, "two")
\end{ExampleCode}
\end{Examples}

