R/paste0.R

In Dasonk/future2.15: Imports functions that were introducted in 2.15

#' Concatenate Strings
#' 
#' concatenate vectors after converting to character.
#' 
#' @inheritParams base::paste
#' 
#' @section Details:
#' paste converts its arguments (via as.character) to 
#' character strings, and concatenates them (separating
#' them by the string given by sep). If the arguments are
#' vectors, they are concatenated term-by-term to give a
#' character vector result. Vector arguments are recycled
#' as needed, with zero-length arguments being recycled to "".
#'
#' Note that paste() coerces NA_character_, the character 
#' missing value, to "NA" which may seem undesirable, e.g., 
#' when pasting two character vectors, or very desirable, 
#' e.g. in paste("the value of p is ", p).
#' 
#' paste0(..., collapse) is equivalent to 
#' paste(..., sep = "", collapse), slightly more efficiently.
#'
#' If a value is specified for collapse, the values in the 
#' result are then concatenated into a single string, with 
#' the elements being separated by the value of collapse.
#'
#' @section Value:
#' A character vector of the concatenated values. This will 
#' be of length zero if all the objects are, unless collapse 
#' is non-NULL in which case it is a single empty string.
#'
#' If any input into an element of the result is in UTF-8 
#' (and none are declared with encoding "bytes"), that 
#' element will be in UTF-8, otherwise in the current 
#' encoding in which case the encoding of the element is 
#' declared if the current locale is either Latin-1 or UTF-8, 
#' at least one of the corresponding inputs (including separators) 
#' had a declared encoding and all inputs were either ASCII or 
#' declared.
#' 
#' If an input into an element is declared with encoding 
#' "bytes", no translation will be done of any of the elements 
#' and the resulting element will have encoding "bytes". 
#' If collapse is non-NULL, this applies also to the second, 
#' collapsing, phase, but some translation may have been done 
#' in pasting object together in the first phase.
#' 
#' @references Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
#' @seealso String manipulation with \code{\link[base]{as.character}},
#' \code{\link[base]{substr}}, \code{\link[base]{nchar}},
#' \code{\link[base]{strsplit}}; further, \code{\link[base]{cat}}
#' which concatenates and writes to a file, and \code{\link[base]{sprintf}}
#' for c linke string construction.
#' 
#' `\code{\link[grDevices]{plotmath}}' for the use of paste in plot annotation.
#' 
#' @export
#' @examples
#' stopifnot(identical(paste ("A", 1:6, sep = ""), paste0("A", 1:6)))
paste0 <- function(..., collapse = NULL){
    paste(..., sep = "", collapse = collapse)
}