assert_expr: Assert Argument is an Expression

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

Assert Argument is an Expression

Description

Assert Argument is an Expression

Usage

assert_expr(
  arg,
  optional = FALSE,
  arg_name = gsub("^enexpr\\((.*)\\)$", "\\1", rlang::caller_arg(arg)),
  message = NULL,
  class = "assert_expr",
  call = parent.frame()
)

Arguments

arg	A function argument to be checked Default value none
optional	Is the checked argument optional? If set to FALSE and arg is NULL then an error is thrown Default value FALSE
arg_name	By default the expression specified for arg is used. If it is of the form ⁠enexpr(<argument name>)⁠, the enexpr() part is removed. For example if arg = enexpr(filter_add) is specified, arg_name defaults to "filter_add" Default value gsub("^enexpr\((.*)\)$", "\1", 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 an expression, i.e. either a symbol or a call, or 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_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(), assert_varval_list()

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