R/sources.r

In hadley/packman:

#' A list of sources.
#' 
#' @param ... individual source objects
#' @param .sources a list of source objects
#' @export
#' @keywords internal
#' @seealso \code{\link{default_sources()}} for a list of sources generated
#'   to represent a useful set of resources.
sources <- function(..., .sources = list()) {
  source1 <- lapply(compact(list(...)), as.sources)
  source2 <- list(as.sources(compact(.sources)))

  sources <- unlist(c(source1, source2), recursive = FALSE, use.names = FALSE)
  structure(sources, class = c("sources", "source"))
}
#' @S3method c sources
c.sources <- function(...) {
  sources(...)
}

as.sources <- function(x) UseMethod("as.sources")
#' @S3method as.sources source
as.sources.source <- function(x) list(x)
#' @S3method as.sources sources
as.sources.sources <- function(x) x
#' @S3method as.sources sources
as.sources.list <- function(x) x

#' @S3method package_info sources
package_info.sources <- function(source, package, version = NULL) {
  for(single in source) {
    if (has_package(single, package, version)) {
      return(package_info(single, package))
    }
  }
  NULL
}

#' @S3method has_package sources
has_package.sources <- function(source, package) {
  for(single in source) {
    if (has_package(single, package)) {
      return(TRUE)
    }
  }
  FALSE
}