min_row = 0 and max_row = max_nrow() to check_data to allow checking of the number of rows.Added argument key = character(0) to check_data to allow checking of a unique key.
Added stricter variants of check_data called check_data2 and check_data3 as well as an alias check_data1 for check_data and deprecated check_data.
check_vector to check the class and values of a vector.check_scalar to check the class and values of a scalar.check_flag, check_int, check_count, check_string, check_date and check_time functions for specific scalars.check_data_frame to check if an object is a data frame.check_rows to check the number of rows in a data frame.check_cols to check the names of columns in a data frame.check_values to check the classes and values of the columns in a data frame.check_key to check that particular columns represent unique keys.check_join to check a many-to-one join between two data frames.max_nrow() to return the theoretical maximum number of rows.Added function min_integer as wrapper for -.Machine$integer.max.
Added argument data_name = substitute(data) to all functions so users can overide the name of data.
check_data is now invisible.max_integer as wrapper for .Machine$integer.max.check_data now lists specific permitted values if 5 or less (if 3 or less for character)