Check if an argument is a single atomic value

Check if an argument is a single atomic value

checkScalar(x, na.ok = FALSE, null.ok = FALSE)

check_scalar(x, na.ok = FALSE, null.ok = FALSE)

assertScalar(
  x,
  na.ok = FALSE,
  null.ok = FALSE,
  .var.name = vname(x),
  add = NULL
)

assert_scalar(
  x,
  na.ok = FALSE,
  null.ok = FALSE,
  .var.name = vname(x),
  add = NULL
)

testScalar(x, na.ok = FALSE, null.ok = FALSE)

test_scalar(x, na.ok = FALSE, null.ok = FALSE)

expect_scalar(x, na.ok = FALSE, null.ok = FALSE, info = NULL, label = vname(x))

Arguments

x

[any]
Object to check.

na.ok

[logical(1)]
Are missing values allowed? Default is FALSE.

null.ok

[logical(1)]
If set to TRUE, x may also be NULL. In this case only a type check of x is performed, all additional checks are disabled.

.var.name

[character(1)]
Name of the checked object to print in assertions. Defaults to the heuristic implemented in vname.

add

[AssertCollection]
Collection to store assertion messages. See AssertCollection.

info

[character(1)]
Extra information to be included in the message for the testthat reporter. See expect_that.

label

[character(1)]
Name of the checked object to print in messages. Defaults to the heuristic implemented in vname.

Value

Depending on the function prefix: If the check is successful, the functions

assertScalar/assert_scalar return

x invisibly, whereas

checkScalar/check_scalar and

testScalar/test_scalar return

TRUE. If the check is not successful,

assertScalar/assert_scalar

throws an error message,

testScalar/test_scalar

returns FALSE, and checkScalar/check_scalar

return a string with the error message. The function expect_scalar always returns an

expectation.

Details

This function does not distinguish between NA, NA_integer_, NA_real_, NA_complex_ NA_character_ and NaN.

See also

Other scalars: checkCount(), checkFlag(), checkInt(), checkNumber(), checkScalarNA(), checkString()

Examples

testScalar(1)
#> [1] TRUE
testScalar(1:10)
#> [1] FALSE