need something that removes environments from functions

[mb706]

I want to save an anonymous function in an object and serialize that object, but that object should not grow huge. It is then necessary that the function's environment hierarchy doesn't contain too much other stuff.

Usecase:

x = 1
large_obj = [huge object that takes lots of memory]
want_to_serialize = function(arg) return(arg + x)
saveRDS(want_to_serialize, "savefile.rds")

want_to_serialize's environment now contains large_obj and the savefile grows large. Instead I would want a function detachEnv(fun, keep, basis):

want_to_serialize_lean = detachEnv(want_to_serialize, keep = "x")
saveRDS(want_to_serialize_lean, "savefile.rds")

code for this:

# removes the environment from fun and potentially wraps it in a new environment
detachEnv <- function(fun, keep = character(0), basis = topenv(parent.frame())) {
  assertEnvironment(basis)
  assertCharacter(keep, any.missing = FALSE)
  assertFunction(fun)
  if (length(keep)) {
    keepvals <- mget(keep, parent.frame(), inherits = TRUE)
    basis <- new.env(parent = basis, size = length(keepvals))
    mapply(assign, names(keepvals), keepvals, MoreArgs = list(envir = basis))
  }
  environment(fun) <- basis
  fun
}

name up for debate

[mllg]

https://github.com/r-lib/carrier/

Something like this?

[berndbischl]

i think they do this in tidymodels too

[mb706]

this, only without the tidyverse awfulness

[mllg]

Closed in #50 ?