Keep Only Specified Objects in an Environment — rm_all

Removes every object in the caller's environment except the ones named in vector. Prompts for confirmation in interactive sessions unless .dontask = TRUE; proceeds without prompting in non-interactive sessions (scripts, R CMD check, knitr rendering), since readline() would otherwise hang there.

Usage

rm_all_except(vector, .dontask = FALSE, env = parent.frame())

Arguments

vector: Character vector of object names to keep.
.dontask: Logical (default FALSE); skip the confirmation prompt.
env: Environment to operate on; defaults to parent.frame().

Value

Invisibly, NULL.

Details

vector must be a character vector of object names, so the names are quoted: rm_all_except(c("a", "b")), not rm_all_except(c(a, b)). Every name has to be an object of the calling environment itself (not of one above it); otherwise the function stops before it removes anything. A misspelt name used to pass unnoticed and remove every object, the one that was meant to be kept included.

Called from inside a function, rm_all_except() works on that function's own environment, so the function's arguments are removed too unless they are named in vector.

Examples

e <- new.env()
local({a <- 1; b <- 2; rm_all_except("a", .dontask = TRUE)}, envir = e)
#> Removing objects:
#> 	 b
ls(e)
#> [1] "a"