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Scalar type predicates

Source: R/are_types.r
are-scalar-type-predicates.Rd

Wrappers around rlang scalar type predicates that allow multiple objects to be passed. The following documentation is adapted from the rlang documentation:

These predicates check for a given type and whether the vector is "scalar", that is, of length 1.

In addition to the length check, are_string() and are_bool() return FALSE if their input is missing. This is useful for type-checking arguments, when your function expects a single string or a single TRUE or FALSE.

Usage

are_scalar_list(..., .all = FALSE)

are_scalar_atomic(..., .all = FALSE)

are_scalar_vector(..., .all = FALSE)

are_scalar_integer(..., .all = FALSE)

are_scalar_double(..., .all = FALSE)

are_scalar_complex(..., .all = FALSE)

are_scalar_character(..., .all = FALSE)

are_string(..., .string = NULL, .all = FALSE)

are_scalar_logical(..., .all = FALSE)

are_bool(..., .all = FALSE)

are_scalar_raw(..., .all = FALSE)

are_scalar_bytes(..., .all = FALSE)

Arguments

...

Objects to be tested.

.all

Whether to return if all arguments are TRUE.

.string

A string/character vector to compare to the inputs.

Value

Named logical, or unnamed boolean if .all is TRUE.

Details

The optional input of .string can be given character vectors that map to the arguments in .... If unnamed vector/list, the input must either be the same length as the number of arguments given to ..., or length 1: which is then recycled to the number number of arguments given to .... Alternatively, a named vector/list can be given, where the values for matching named elements are passed to the type predicate, but unmatched names are passed NULL. List inputs can pass different character vectors for each dot argument. When a character vector is given for a single argument, TRUE is returned if at least one element is equal.

See also

are-type-predicates, are-bare-type-predicates

Examples

x <- 1
y <- list()
z <- mean

are_scalar_list(x, y, z, list(1))
#>       x       y       z list(1) 
#>   FALSE   FALSE   FALSE    TRUE 

# `.all` can be given to test if all inputs
# evaluate to TRUE
are_list(x, y, z, list(1), .all = TRUE)
#> [1] FALSE