assert_symbol {admiraldev} | R Documentation |
Is an Argument a Symbol?
Description
Checks if an argument is a symbol
Usage
assert_symbol(arg, optional = FALSE)
Arguments
arg |
A function argument to be checked. Must be a |
optional |
Is the checked argument optional? If set to |
Value
The function throws an error if arg
is not a symbol and returns the input
invisibly otherwise.
See Also
Checks for valid input and returns warning or errors messages:
assert_atomic_vector()
,
assert_character_scalar()
,
assert_character_vector()
,
assert_data_frame()
,
assert_date_vector()
,
assert_expr_list()
,
assert_expr()
,
assert_filter_cond()
,
assert_function()
,
assert_integer_scalar()
,
assert_list_element()
,
assert_list_of()
,
assert_logical_scalar()
,
assert_named()
,
assert_numeric_vector()
,
assert_one_to_one()
,
assert_param_does_not_exist()
,
assert_s3_class()
,
assert_same_type()
,
assert_unit()
,
assert_vars()
,
assert_varval_list()
Examples
library(pharmaversesdtm)
library(dplyr, warn.conflicts = FALSE)
library(rlang)
data(dm)
example_fun <- function(dat, var) {
var <- assert_symbol(enexpr(var))
select(dat, !!var)
}
example_fun(dm, USUBJID)
try(example_fun(dm))
try(example_fun(dm, "USUBJID"))
try(example_fun(dm, toupper(PARAMCD)))