If

In attempt: Tools for Defensive Programming

knitr::opts_chunk$set(
  error = TRUE,
  collapse = TRUE,
  comment = "#>"
)
library(attempt)

if_ conditions

if_none(), if_any() and if_all() test the elements of the list.

if_all(1:10, ~ .x < 11, ~ return(letters[1:10]))

if_any(1:10, is.numeric, ~ "Yay!")

if_none(1:10, is.character, ~ rnorm(10))

The defaut for all .p is isTRUE(). So you can:

a <- c(FALSE, TRUE, TRUE, TRUE)

if_any(a, .f = ~ "nop!")

if_then() performs a simple "if this then do that":

if_then(1, is.numeric, ~ "nop!")

if_not() runs .f if .p(.x) is not TRUE :

if_not(.x = 1, .p = is.character, ~ ".x is not a character")

And if_else() is a wrapper around base::ifelse().

If you want these function to return a value, you need to wrap these values into a mapper / a function. E.g, to return a vector, you'll need to write if_then(1, is.numeric, ~ "Yay").

a <- if_else(1, is.numeric, ~ "Yay", ~ "Nay")
a

attempt documentation built on May 4, 2020, 1:05 a.m.