Bryan Cantrill interviews Arthur Whitney (2009)

Re:Bryan Cantrill interviews Arthur Whitney (2009) by dang on Sunday December 01, 2019 @03:25AM (#21674541)

A thread from 2014: https://news.ycombinator.com/item?id=8476120

A couple from 2009: https://news.ycombinator.com/item?id=650149

https://news.ycombinator.com/item?id=561443

I remember seeing that at the time but didn't notice who was the interviewer!

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Re:Bryan Cantrill interviews Arthur Whitney (2009) by akkartik on Monday December 02, 2019 @12:50AM (#21680133)

https://news.ycombinator.com/item?id=561443#562884

Does anybody know how array languages handle pointers and trees?

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Re:Bryan Cantrill interviews Arthur Whitney (2009) by refset on Monday December 02, 2019 @01:03AM (#21680181)

I believe Aaron Hsu's work on tree processing for Co-dfns [0] is a novel example of tree handling - a data parallel compiler for efficient compilation on a GPU using extensive tree-oriented "nanopass" transformations [1].

[0] https://github.com/Co-dfns/Co-dfns

[1] https://dyalog.tv/Dyalog18/?v=hzPd3umu78g

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Re:Bryan Cantrill interviews Arthur Whitney (2009) by akkartik on Monday December 02, 2019 @01:36AM (#21680316)

Holy crap, that video is mind-blowing. Thank you! I was vaguely aware of Co-dfns before, but now it's squarely on my radar.

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Re:Bryan Cantrill interviews Arthur Whitney (2009) by geocar on Monday December 02, 2019 @03:15AM (#21680743)

If you have cycles in your graph, you can build a tree out of a vector of indices, or as a table of parent/child node keys. The former is what John Scholes does[1], and the latter has plenty of common SQL examples.

[1]: https://youtu.be/DsZdfnlh_d0

If you have a non-cyclic tree (e.g. a 256-trie) you can nest it directly: @/ will traverse to nodes, and COW keeps updates from trashing memory too much.

However trees are rarely the best data structure: Binary search on a sorted list can beat b-trees simply because the end of the search will already be in cache, so for a routing table of IP address ranges, I use something like:

    ipStart where ipStart bin x

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Re:Bryan Cantrill interviews Arthur Whitney (2009) by vchak1 on Monday December 02, 2019 @01:12AM (#21680212)

John Earnest also details how trees are handled in K (an array based language invented by Arthur Whitney). https://github.com/JohnEarnest/ok/blob/gh-pages/docs/Trees.m...

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Re:Bryan Cantrill interviews Arthur Whitney (2009) by RodgerTheGreat on Monday December 02, 2019 @01:35AM (#21680313)

I also wrote a paper about recursive combinators which touches on these ideas a bit: http://archive.vector.org.uk/art10501740

And I translated some of Aaron Hsu's APL ideas into k5. With a little massaging they work just as well: https://github.com/JohnEarnest/ok/blob/gh-pages/examples/key...

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