Today I stumbled across the fact that the sequence operator can be chained:
> 1...5...1 (1 2 3 4 5 4 3 2 1) You can even reduce with it: > [...] 1, 5, 3, 10, 8 (1 2 3 4 5 4 3 4 5 6 7 8 9 10 9 8) And even sequences with custom generators can be joined: > 0,1,*+*...144,*/2...9 (0 1 1 2 3 5 8 13 21 34 55 89 144 72 36 18 9) Pretty cool! The online docs for the operator don't seem to offer even a hint that this is possible, though. Anyway, I was hoping that someone with more insight into the internals could describe how this works. Simple concatenation, or can sequences lazily dispatch to another sequence once exhausted, or...?