notFalsy: Judgement of falsy value

In spsUtil: 'systemPipeShiny' Utility Functions

Description

judge if an object is or not a falsy value. This includes: empty value, empty string "", NULL, NA, length of 0 and FALSE itself

Usage

notFalsy(x)

isFalsy(x)

emptyIsFalse(x)

Arguments

x	any R object

Details

R does not have good built-in methods to judge falsy values and these kind of values often cause errors in if conditions, for example if(NULL) 1 else 2 will cause error. So this function will be useful to handle this kind of situations: if(notFalsy(NULL)) 1 else 2.

1. not working on S4 class objects.

2. isFalsy is the reverse of notFalsy: isFalsy(x) = !notFalsy(x)

3. emptyIsFalse is the old name for notFalsy

Useful for if statement. Normal empty object in if will spawn error. Wrap the expression with emptyIsFalse can avoid this. See examples

Value

NA, "", NULL, length(0), nchar == 0 and FALSE will return FALSE, otherwise TRUE in notFalsy and the opposite in isFalsy

Examples

notFalsy(NULL)
notFalsy(NA)
notFalsy("")
try(`if(NULL) "not empty" else "empty"`) # this will generate error
if(notFalsy(NULL)) "not falsy" else "falsy" # but this will work
# Similar for `NA`, `""`, `character(0)` and more
isFalsy(NULL)
isFalsy(NA)
isFalsy("")

spsUtil documentation built on Oct. 31, 2021, 1:06 a.m.