inject_funs {evaluate} | R Documentation |
evaluate()
Create functions in the environment specified in the envir
argument of
evaluate()
. This can be helpful if you want to substitute certain
functions when evaluating the code. To make sure it does not wipe out
existing functions in the environment, only functions that do not exist in
the environment are injected.
inject_funs(...)
... |
Named arguments of functions. If empty, previously injected functions will be emptied. |
Invisibly returns previous values.
For expert use only. Do not use it unless you clearly understand it.
library(evaluate)
# normally you cannot capture the output of system
evaluate("system('R --version')")
# replace the system() function
old <- inject_funs(system = function(...) {
cat(base::system(..., intern = TRUE), sep = "\n")
})
evaluate("system('R --version')")
# restore previously injected functions
inject_funs(old)