R/compose.R

In peterhurford/funtools: Make R functions more fun

#' Compose two binary functions using and.
#' @param f1 function. A function to compose.
#' @param f2 function. A function to compose.
#' @return TRUE or FALSE whether the results of both functions are TRUE.
#' @export
fandcompose <- `%&>%` <- function(f1, f2) { function(...) { f1(...) & f2(...) }}

#' Compose two binary functions using or.
#' @param f1 function. A function to compose.
#' @param f2 function. A function to compose.
#' @return TRUE or FALSE whether the result of one or both functions is TRUE.
#' @export
forcompose <- `%|>%` <- function(f1, f2) { function(...) { f1(...) | f2(...) }}


#' Compose on NA, NULL, or lenth-0 (empty) values.
#' @param x object. This object will be returned if non-NA, non-NULL, non-empty.
#' @param y object. This object will be returned if x is NA, NULL, or empty.
#' @return either x or y.
#' @export
`%or%` <- `%|%` <- function(x, y) {
  if (is.null(x) || is.na(x) || length(x) == 0) { y } else { x }
}