CODEWITHSUNDEEP
r
Jrakru56
Jrakru56

Reputation: 1321

safely get variable from enviroment

When I execute: 

my_env <- new.env(parent = emptyenv())
test <- purrr::safely(get("meta", envir = my_env))

I get the following error:

Error in get("meta") : object 'meta' not found

The error is correct in the sense of that the meta variable is not defined in the environment but my line of thinking was that safely would return a NULL in that case.

I can get around the error by using checking using exists first but I was curious about why safely fails. Am I wrong in thinking of safely as the equivalent of a try-catch?

Upvotes: 0

Views: 31

Answers (1)

IRTFM
IRTFM

Reputation: 263481

You are misinterpreting the actions of the safely function. It was actually succeeding. If you had examined the value of test, you should have seen:

> test
[1] "Error in get(\"meta\", env = my_env) : object 'meta' not found\n"
attr(,"class")
[1] "try-error"
attr(,"condition")
<simpleError in get("meta", env = my_env): object 'meta' not found

To suppress error messages from being visible at the console you can either turn off reporting with options(show.error.messages = FALSE) or you can redirect the destination of stderr().

Upvotes: 1

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