R/clear.R

In paodan/funcTools: some useful function tools in practice

#' @title Removes the variables from environment\cr
#' @description \code{clear} removes the variables, matched by the pattern,
#' from the environment (the default is parent environment).
#' It will return the name of variables which have been removed.
#' @param pattern A character string. The regular expression pattern of
#' variable names to be removed.
#' @param all.names Logical. If TRUE, all object names are removed (except 
#' .Random.seed). If FALSE, object names which begin with a . are omitted.
#' @param envir An alternative argument to name for specifying the environment.
#' @return The name of variables which have been removed.
#' @seealso \code{\link{rm}}, \url{https://github.com/paodan/funcTools}
#' @export
#' @examples
#' \dontrun{
#' # Remove all (visible) variables in the Global Environment.
#' x1 = 1
#' x3 = "a"
#' xx = TRUE
#' y = function(x) x
#' y1 = 1:4
#' yx = list(y = 1, x = 3)
#' .x = data.frame(rnorm(5))
#' ls(all.names = TRUE)
#' clear()
#' ls(all.names = TRUE)
#'
#' # Remove all variables including (invisible) variables begin with a ".".
#' clear(all.names = TRUE)
#' ls(all.names = TRUE)
#'
#' # Remove variables begin with "x".
#' x1 = 1
#' x3 = "a"
#' xx = TRUE
#' y = function(x) x
#' y1 = 1:4
#' yx = list(y = 1, x = 3)
#' .x = data.frame(rnorm(5))
#' clear("^x")
#' ls(all.names = TRUE)
#'
#' # Remove variables end with "x".
#' clear("x$")
#' ls(all.names = TRUE)
#' }
#' 
clear = function(pattern = "*", all.names = FALSE, envir = parent.frame()){
  List = ls(pattern = pattern, all.names = all.names, envir = envir)
  List = setdiff(List, ".Random.seed")
  if(length(List)){
    message("Remove: \n", paste0(List, collapse = ", "))
    rm(list = List, envir = envir)
    gc(reset = TRUE)
  } else {
    message("Nothing Removed!")
  }
  invisible(List)
}