There’s an unfortunate overlap in terminology: :ets.match takes a “match pattern”, not a match specification. The documentation for :ets.select/2 demonstrates this:
ets:match(Table,{'$1','$2','$3'})
# is equivalent to
ets:select(Table,[{{'$1','$2','$3'},[],['$$']}])
Demo:
iex(1)> tab = :ets.new(:foo, [:ordered_set])
#Reference<0.3893230368.2635726851.91982>
iex(3)> :ets.insert(tab, {{"a", 1, "b"}, "c"})
true
iex(4)> :ets.insert(tab, {{"d", 2, "e"}, "f"})
true
iex(6)> :ets.select(tab, [{{{:"$1", :"$2", :"$3"}, :"$4"}, [{:<, :"$2", 2}], [:"$_"]}])
[{{"a", 1, "b"}, "c"}]
