possibly()

Gevorderd functioneel programmeren met purrr

Colin Fay

Data Scientist & R Hacker at ThinkR

About possibly()

`possibly() creates a function that returns either:

  • the result

  • the value of otherwise

library(purrr)
possible_sum <- possibly(sum, otherwise = "nop")
possible_sum(1)

possible_sum("a")

0

"nop"
Gevorderd functioneel programmeren met purrr

Using possibly()

possibly() can return:

  • A logical
ps <- possibly(sum, FALSE)
ps("a")

FALSE
  • A NA
ps <- possibly(sum, NA)
ps("a")

NA

 

  • A character
ps <- possibly(sum, "nope")
ps("a")

"nope"
  • A number
ps <- possibly(sum, 0)
ps("a")

0
Gevorderd functioneel programmeren met purrr

Let's practice!

Gevorderd functioneel programmeren met purrr

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