assert_varval_list: Is an Argument a Variable-Value List?

In admiraldev: Utility Functions and Development Tools for the Admiral Package Family

Is an Argument a Variable-Value List?

Description

Checks if the argument is a list of expressions where the expressions are variable-value pairs. The value can be a symbol, a string, a numeric, an expression, or NA.

Usage

assert_varval_list(
  arg,
  required_elements = NULL,
  accept_expr = TRUE,
  accept_var = FALSE,
  optional = FALSE,
  arg_name = rlang::caller_arg(arg),
  message = NULL,
  class = "assert_varval_list",
  call = parent.frame()
)

Arguments

arg	A function argument to be checked Default value none
required_elements	A character vector of names that must be present in arg Default value NULL
accept_expr	Should expressions on the right hand side be accepted? Default value TRUE
accept_var	Should unnamed variable names (e.g. exprs(USUBJID)) on the right hand side be accepted? Default value FALSE
optional	Is the checked argument optional? If set to FALSE and arg is NULL then an error is thrown. Default value FALSE
arg_name	string indicating the label/symbol of the object being checked. Default value rlang::caller_arg(arg)
message	string passed to cli::cli_abort(message). When NULL, default messaging is used (see examples for default messages). "{arg_name}" can be used in messaging. Default value NULL
class	Subclass of the condition.
call	The execution environment of a currently running function, e.g. call = caller_env(). The corresponding function call is retrieved and mentioned in error messages as the source of the error. You only need to supply call when throwing a condition from a helper function which wouldn't be relevant to mention in the message. Can also be NULL or a defused function call to respectively not display any call or hard-code a code to display. For more information about error calls, see Including function calls in error messages.

Value

The function throws an error if arg is not a list of variable-value expressions. Otherwise, the input it returned invisibly.

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(), assert_expr_list(), 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_symbol(), assert_unit(), assert_vars()

Examples

library(dplyr, warn.conflicts = FALSE)
library(rlang)

example_fun <- function(vars) {
  assert_varval_list(vars)
}
example_fun(exprs(DTHDOM = "AE", DTHSEQ = AESEQ))

try(example_fun(exprs("AE", DTSEQ = AESEQ)))

admiraldev documentation built on June 26, 2025, 1:09 a.m.