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Check Logical Argument

Source: R/arg_logical.R
arg_logical.Rd

Checks whether an argument is a logical vector (arg_logical()) or a logical scalar (arg_flag()), i.e., a single logical value. Logical values include TRUE and FALSE.

Usage

arg_logical(x, .arg = rlang::caller_arg(x), .msg = NULL, .call)

arg_flag(x, .arg = rlang::caller_arg(x), .msg = NULL, .call)

Arguments

x

the argument to be checked

.arg

the name of the argument supplied to x to appear in error messages. The default is to extract the argument's name using rlang::caller_arg(). Ignored if .msg is supplied.

.msg

an optional alternative message to display if an error is thrown instead of the default message.

.call

the execution environment of a currently running function, e.g. .call = rlang::current_env(). The corresponding function call is retrieved and mentioned in error messages as the source of the error. Passed to err(). Set to NULL to omit call information. The default is to search along the call stack for the first user-facing function in another package, if any.

Value

Returns NULL invisibly if an error is not thrown.

Details

NA values in arg_flag() will cause an error to be thrown.

See also

is.logical(), rlang::is_bool()

Examples

obj <- TRUE

try(arg_flag(obj))    # No error
try(arg_logical(obj)) # No error

obj <- c(TRUE, FALSE)

try(arg_flag(obj))    # Error: must be a scalar
#> Error : `obj` must be a single logical value (TRUE or FALSE).
try(arg_logical(obj)) # No error

obj <- 1L

try(arg_flag(obj))    # Error must be logical
#> Error : `obj` must be a logical value (TRUE or FALSE).
try(arg_logical(obj)) # Error must be logical
#> Error : `obj` must be a logical vector.