ensure_scalar_integer(object, allow.na = FALSE, allow.null = FALSE, default = NULL)
ensure_scalar_double(object, allow.na = FALSE, allow.null = FALSE, default = NULL)
ensure_scalar_boolean(object, allow.na = FALSE, allow.null = FALSE, default = NULL)
ensure_scalar_character(object, allow.na = FALSE, allow.null = FALSE, default = NULL)NA values permitted for this object?NULL values permitted for this object?object is NULL, what value should
be used in its place? If default is specified, allow.null
is ignored (and assumed to be TRUE).