vroom_lines() is similar to readLines(), however it reads the lines
lazily like vroom(), so operations like length(), head(), tail() and sample()
can be done much more efficiently without reading all the data into R.
Control which column types use Altrep representations,
either a character vector of types, TRUE or FALSE. See
vroom_altrep_opts() for for full details.
num_threads
Number of threads to use when reading and materializing vectors.
progress
Display a progress bar? By default it will only display
in an interactive session and not while knitting a document. The display
is updated every 50,000 values and will only display if estimated reading
time is 5 seconds or more. The automatic progress bar can be disabled by
setting option readr.show_progress to FALSE.