Raul Miller wrote:
> foo=: <^:{./.~ [: +/\ 0,2 ~:/\ ]
REB asked for a foo such that:
foo 1 1 2 2 3 3 4 2 3 4 4 1 2 2 2 1
+---+---------------------------+-+-------+-+
|1 1|+---+---------+-+---------+|1|+-----+|1|
| ||2 2|+---+---+|2|+-+-----+|| ||2 2 2|| |
| || ||3 3|+-+|| ||3|+---+||| |+-----+| |
| || || ||4||| || ||4 4|||| | | |
| || || |+-+|| || |+---+||| | | |
| || |+---+---+| |+-+-----+|| | | |
| |+---+---------+-+---------+| | | |
+---+---------------------------+-+-------+-+
Your foo gives:
foo 1 1 2 2 3 3 4 2 3 4 4 1 2 2 2 1
+---+-----+-------+-------+---+-----+---------+-+-------+-+
|1 1|+---+|+-----+|+-----+|+-+|+---+|+-------+|1|+-----+|1|
| ||2 2|||+---+|||+---+|||2|||+-+|||+-----+|| ||2 2 2|| |
| |+---+|||3 3|||||+-+|||+-+|||3|||||+---+||| |+-----+| |
| | ||+---+|||||4|||| ||+-+|||||4 4|||| | | |
| | |+-----+|||+-+||| |+---+|||+---+||| | | |
| | | ||+---+|| | ||+-----+|| | | |
| | | |+-----+| | |+-------+| | | |
+---+-----+-------+-------+---+-----+---------+-+-------+-+
That is, you have the depth of each element right, but you still need to
group the elements appropriately. It helps to think of 1 1 2 2 3 3 4 2 3 4
4 1 2 2 2 1 as representing a parenthesized expression, with greater numbers
being more deeply nested.
-Dan
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