Tab Completion in IEx

IEx has tab completion of library functions, just like IRB. To see all the built-in Stream functions, just type Stream. and hit TAB, and you'll get output like this:

iex(1) Stream.
Reducers        chunk/2         chunk/4         chunk_by/2
concat/1        concat/2        cycle/1         dedup/1
dedup_by/2      drop/2          drop_while/2    each/2
filter/2        filter_map/3    flat_map/2      interval/1
into/3          iterate/2       map/2           reject/2
repeatedly/1    resource/3      run/1           scan/2
scan/3          take/2          take_every/2    take_while/2
timer/1         transform/3     transform/4     unfold/2
uniq/2          with_index/2    zip/2

This is a nice feature when you're experimenting in the REPL.

h/t Micah Cooper