% File src/library/utils/man/withVisible.Rd % Part of the R package, http://www.R-project.org % Copyright 1995-2010 R Core Team % Distributed under GPL 2 or later \name{withVisible} \alias{withVisible} \title{Return both a value and its visibility} \description{ This function evaluates an expression, returning it in a two element list containing its value and a flag showing whether it would automatically print. } \usage{ withVisible(x) } \arguments{ \item{x}{ An expression to be evaluated. } } \details{ The argument is evaluated in the caller's context. This is a \link{primitive} function. } \value{ \item{value }{The value of \code{x} after evaluation.} \item{visible }{logical; whether the value would auto-print.} } \seealso{\code{\link{invisible}}, \code{\link{eval}}} \examples{ x <- 1 withVisible(x <- 1) x withVisible(x) # Wrap the call in evalq() for special handling df <- data.frame(a = 1:5, b = 1:5) evalq(withVisible(a + b), envir = df) } \keyword{programming}