R/internal.R

In Q7: Types and Features for Object Oriented Programming

strip_ends <- function(text){
    `if`(length(text) > 2,
         text[2:(length(text) - 1)],
         text)
}

inject_text <- function(text_1, text_2, index){
    c(text_1[1:index],
      text_2,
      text_1[(index + 1):length(text_1)])
}

migrate_elements <- function(from, to){
    mapply(assign,
           x  = ls(from),
           value = mget(ls(from), from),
           envir = list(to))
    invisible(to)
}

migrate_fns <- function(from, to) {
  sapply(
    Filter(function(.){
      f <- get(., envir = from)
      is.function(f) &&
        identical(environment(f),
                  from)
    },
    ls(envir = from)),
    function(.) {
      f <- get(., envir = from)
      environment(f) <- to
      assign(., f, envir = to)
    })
  invisible(to)
}