R/lifecycle-superseded.R

Defines functions env_bury

Documented in env_bury

#' Mask bindings by defining symbols deeper in a scope
#'
#' @description
#' `r lifecycle::badge("superseded")`
#'
#' This function is superseded. Please use [env()] (and possibly
#' [set_env()] if you're masking the bindings for another object like
#' a closure or a formula) instead.
#'
#' `env_bury()` is like [env_bind()] but it creates the bindings in a
#' new child environment. This makes sure the new bindings have
#' precedence over old ones, without altering existing environments.
#' Unlike `env_bind()`, this function does not have side effects and
#' returns a new environment (or object wrapping that environment).
#'
#' @inheritParams env_bind
#' @return A copy of `.env` enclosing the new environment containing
#'   bindings to `...` arguments.
#' @seealso [env_bind()], [env_unbind()]
#'
#' @keywords internal
#' @export
#' @examples
#' orig_env <- env(a = 10)
#' fn <- set_env(function() a, orig_env)
#'
#' # fn() currently sees `a` as the value `10`:
#' fn()
#'
#' # env_bury() will bury the current scope of fn() behind a new
#' # environment:
#' fn <- env_bury(fn, a = 1000)
#' fn()
#'
#' # Even though the symbol `a` is still defined deeper in the scope:
#' orig_env$a
env_bury <- function(.env, ...) {
  env_ <- get_env(.env)
  env_ <- child_env(env_, ...)
  set_env(.env, env_)
}
hadley/rlang documentation built on Nov. 1, 2024, 4 p.m.