Descriptions of the parameters and return values for the chk functions
The chk_ function throws an informative error if the test fails or
returns the original object if successful so it can used in pipes.
The vld_ function returns a flag indicating whether the test was met.
The object to check.
A string of the name of object x or NULL.
An object to check against.
A flag specifying whether to check the other parameters.
A chk_ function.
A non-negative numeric scalar.
A character vector of the permitted file extensions (without the .).
A flag specifying whether the files/directories must (or must not) exist.
A non-missing scalar of a value.
A non-missing sorted vector of length 2 of the lower and upper permitted values.
A flag specifying whether the range is exclusive.
A string of a regular expression.
A vector of the permitted values.
A string specifying the class.
A count of the length.
A count of the max length.
A count of the number of formal arguments.
A vector of values that cannot be compared. FALSE means that all values can be compared.
A character vector specifying the column names to join x and y on. If named the names are the corresponding columns in x.
A flag specifying whether x must only include columns named in values.
A flag specifying whether the order of columns in x must match names in values.
A flag or a whole numeric vector of the value, value range or possible values.
A character vector of the columns that represent a unique key.
A vld_ function.
Additional arguments.