\name{copyEnv}
\alias{copyEnv}

\alias{l2e}

\title{List-Environment interactions}

\description{
  These functions can be used to make copies of environments, or to
  get/assign all of the objects inside of an environment.
}

\usage{
copyEnv(oldEnv, newEnv, all.names=FALSE)
l2e(vals, envir)
}

\arguments{
  \item{oldEnv}{An environment to copy from}
  \item{newEnv}{An environment to copy to.  If missing, a new environment
  with the same parent environment as oldEnv.}
  \item{envir}{An environment to get/set values to.  For \code{l2e}
  this can be left missing and a new \code{environment} of an
  appropriate size will be returned.}
  \item{vals}{A named list of objects to assign into an environment.
    The names must not include \code{NA} or \code{""} and should
    be unique.}
  \item{all.names}{Whether to retrieve objects with names that start
    with a dot.}
}

\details{
  \code{l2e}: This function takes a named list and assigns all of its
  elements into an environment (using the names to name the objects).
  Unless you have an existing environment which you want to reuse, it
  is best to omit the \code{envir} argument.  This way, the function
  will create a new environment with an efficient initial size.  If the
  names of \code{vals} are not unique, a warning will be raised.  The
  returned environment will contain the value associated with the last
  occurrence of any given duplicated name.
  
  \code{copyEnv}: This function will make a copy of the contents from
  \code{oldEnv} and place them into \code{newEnv}.
}

\author{Jeff Gentry and R. Gentleman}

\seealso{\code{\link{environment}}, \code{\link{as.list}}}

\examples{
   z <- new.env(hash=TRUE, parent=emptyenv(), size=29L)
   multiassign(c("a","b","c"), c(1,2,3), z)

   a <- copyEnv(z)
   ls(a)

   q <- as.list(z)
   g <- new.env(hash=TRUE, parent=emptyenv(), size=29L)
   g <- l2e(q, g)
   ls(g)
   g2 <- l2e(q)
}
\keyword{utilities}