peek_vars()returns the vector of names of the variables currently available for selection.peek_data()returns the whole input vector (only available witheval_select()).
Read the Get started for
examples of how to create selection helpers with peek_vars().
The variable names in a selection context are registered
automatically by eval_select() and eval_rename() for the
duration of the evaluation. peek_vars() is the glue that connects
selection helpers to the current selection
context.