﻿:: { s:i8*, r:{A:i8}, t:{A:i8}* }

Range(3) ++ Range(10)
Chain(Range(3), Range(10))
[1, 2] ++ [3, 4, 5]
Chain([1, 2], [3, 4, 5])
[1, 2] ++ null ++ [3, 4, 5] ++ []
Chain([1, 2], null, [3, 4, 5], [])

s ++ Range(17)
Chain(s, Range(17))
s ++ Range(17) ++ s
Chain(s, Range(17), s)
s ++ Range(17) ++ s ++ Range(5)
Chain(s, Range(17), s, Range(5))

[null] ++ Repeat(r, 3)

GroupBy(Range(20)->Mod(3), it)
