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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Do not modify this file since it was automatically generated from:
%
% withOptions.R
%
% by the Rdoc compiler part of the R.oo package.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\name{withOptions}
\alias{withOptions}
\title{Evaluate an R expression with options set temporarily}
\description{
Evaluate an R expression with options set temporarily.
}
\usage{
withOptions(expr, ..., args=list(), envir=parent.frame())
}
\arguments{
\item{expr}{The R expression to be evaluated.}
\item{...}{Named options to be used.}
\item{args}{(optional) Additional named options specified as a named \code{\link[base]{list}}.}
\item{envir}{The \code{\link[base]{environment}} in which the expression should be evaluated.}
}
\value{
Returns the results of the expression evaluated.
}
\details{
Upon exit (also on errors), this function will reset \emph{all}
options to the state of options available upon entry. This means
any options \emph{modified} but also those \emph{added} when
evaluating \code{expr} will also be undone upon exit.
}
\author{Henrik Bengtsson}
\examples{
print(pi)
# Same, i.e. using default
withOptions({
print(pi)
})
# Printing with two digits
withOptions({
print(pi)
}, digits=2)
# Printing with two digits then with three more
withOptions({
print(pi)
withOptions({
print(pi)
}, digits=getOption("digits")+3)
}, digits=2)
# Still printing with the default
print(pi)
}
\seealso{
Internally, \code{\link[base]{eval}}() is used to evaluate the expression.
and \code{\link[base]{options}}() to set options.
}
\keyword{IO}
\keyword{programming}
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