Even in Elixir, for small lists directly comparing the items with each other is much faster than using a map to store seen elements (which is what Enum.uniq does).
@bmitc’s function is 9x slower than the direct comparison of 4 items on my machine.
Comparison:
direct_compare 17.22 K
find_end_of_first_distinct_window 1.86 K - 9.28x slower +481.00 μs
However, the number of comparisons increases by n-1 for each element added, so there’s probably a point where using a map is faster.
