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Comment by dmagyari | Hacker News Reader

"Instead of allocating Expr objects willy-nilly on the heap, we’ll pack them into a single, contiguous array." Zig compiler pipeline (AST, Zir, Air, Sema) does exactly this on all layers. Not only contiguous, but instead of array-of-structs it is struct-of-arrays, so walking the tree is even more cache friendly. For AST see: https://github.com/ziglang/zig/blob/master/lib/std/zig/Ast.z...

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I work on a C dialect where everything is flattened. JSON and other trees in particular. Binary heaps are flat, merge sort and iterator heaps are absolutely great, can build LSM databases with that. Stacks, circular buffers, hash maps, etc, all flat. Templated output (PHP like) is done by a flat data structure.

https://github.com/gritzko/librdx/blob/master/abc/B.md

Apart from locality and lifetimes, these flat data structures improve composability. When every data structure is a flat buffer, you can mmap them or zip them or send them by the network, all by the same routine. They are uniform like bricks, in a sense.

I worked in a language where all datastructures were "flattened", could be trivially serialized to disk, and read in again. Called print and read. The language was called lisp. All flat, just parens.

Some of my compilers export the AST as lisp trees. Much smaller and more readable than json, and it can be executed. Uniform like bricks

> All flat, just parens.

So not flat then. Prefix is not postfix. Forth, and most concatenative languages, are much closer to actually bein, flat.

Lisp is trivial to flatten, but that's not the same thing.

Makes me wonder if people in APL/J/K community have not been influenced or influencing this kind of technique. IIRC Aaron Hsu does tree processing through arrays (but i'm not skilled enough to analyze his code)

Do you have a link to such an example of Aaron's code? Thank you in advance!

https://scholarworks.iu.edu/dspace/items/3ab772c9-92c9-4f59-...

Iverson's 1962 book also mentions tree representations, see pp45-62: https://archive.org/details/aprogramminglanguage1962/page/n6...

Thanks. Was hoping for low-level code that might even blow a deue(I?)ng(m?)ker's mind on THE semantics-syntax duality..

This was closest: https://www.dyalog.com/blog/2018/01/stackless-traversal/

Your links should still be useful for orienteering!

Can't remember where exactly but he did demo his code in talks/conferences with links.

I've given up on finding relevant low-level CUDA(? tacit? asm??!!) code from Hsu*, but I did push the following to my to-watch stack

https://youtu.be/z8MVKianh54

Does APL need a type system

Guess it's time to reverse whatever else I can find

https://www.dyalog.com/uploads/conference/dyalog16/prerequis...

*Bad faith, or just a run o' the mill, aka compleatly forgiveable profiteering?

Ahh apologies

https://news.ycombinator.com/item?id=13797797

https://news.ycombinator.com/item?id=13576176

He must be referring to https://dl.acm.org/doi/pdf/10.1145/2935323.2935331 ?

Just looking at refs for the moment: Henglein and Hinze's discriminators are interesting, whenever you come back up for air. (are they also amenable to sorting codata?)

The oft-cited R Bernecky is, IIRC, also known as "Boolean Bob" for his SWAR-style algos. EDIT: nope, confused him with R Smith: https://aplwiki.com/wiki/Bob_Smith

(I once asked Boolean Bob if any of his tricks went back to the card processing days —I could even believe the keyed tree* might?— but he was too young to know, and the people he'd have liked to ask are no longer available.)

EDIT: Aardappel also has some interesting languages: https://strlen.com/#programming-languages

* for manipulating Bills of Materials despite the linearity of card decks?

EDIT2: compare "§3.2.1 Constructing Node Coordinates" (p34) with [T in "Table 1.19 Full list matrices of the tree of Fig. 1.16" in A Programming Language (p50): https://archive.org/details/aprogramminglanguage1962/page/n6...

[all three appear to be 1-origin, probably due to the phenomenon mentioned in the footnote on p49 of APL]

Thanks!

[Too low global b/w to feel the adrenalin.. wow.. what was your deduction chain for figuring how BoMs was next item on my stack? Guessing you started from assumption that pure bits mongering are not on the boundary of my ikigais(yet)]

On the heap, I (re)surfaced "Typed Array Intermediate Language" slides, but too low (local) b/w to try to find out^W^W^W^W sus out if this or smth v similar is already in dyalog.com's workflow.

https://news.ycombinator.com/item?id=11974936

>Bernecky

https://news.ycombinator.com/item?id=11963548

What were those slides about formalizing Euclid ?

[Medium b/w vibing that multiplicity of edits is a precise estimate of flow-of-war, ~ webpage memory usage is an accurate estimate of just how well run the entire organization is..]

still haven't refound the slides — every 5 or 6 weeks I get a new idea of who it might have been, but so far to no avail...

[BoMs were complete coincidence]

Slides & conspiracies..

For an vulpine organ they speak very confidently of the f-o-w

https://xcancel.com/benln/status/1873459290562056566

Using kendō vocab I think what they're trying to say with f-o-w is to avoid 2 of the 4 fails: 疑, and (or at least?) 惑.

(interesting that 平常心 is unmarked, while in english the desired state of mind[heart] is marked)

No slides yet, but I finally dug up the quotation I'd promised you last year: Körner, The Pleasures of Counting (1996) p.413 ch.17 "Time and chance" in a footnote (arrived at via a path starting with Enigma decodes!):

> Social Darwinism applies the Darwinian doctrine of survival of the fittest to human society. Rich social Darwinists take wealth as the best indication of fitness to survive, academic social Darwinists take intellectual achievements as the best indication and so on. They are often haunted by the fear that the unfit do not understand this and may outbreed the fit.

疑 is a common failure mode for foxes, yes. 惑 might be interesting for me to consider in the musk-jobs case studies (roughly corresponding to where the confidence shall be reconsidered?) How about OCD? Subset of 惑? Could lead to failure-to-ship for designers..

https://www.thepsmiths.com/p/review-reentry-by-eric-berger

>Part of what makes “founder mode” so effective is that startup founders have both a compensation structure and social permission that lets them treat every single issue that comes up at work as if their family is about to die

(The field promotions and war stories also remind me of 1796-1797)

Aha thanks.

a quick de-Maistre-style counter response before I dive in

  social-darwinists.ch

Would you say (the proddy part of) CH culture is largely pre-1939 compared to the most of the rest of teutonia (some hills of ostmark excepted..& liechtenstein)

(Or even pre XVIII, leaving out AT et al if we review the antisemitism?)

Edit

非常口,平常心?

Update:

What sort of [social-]darwinist might KDA be??? (Ditto for Angus Deaton)

(Just trying to find out how I'd come across .. not as an organizational darwinist ???? ))

https://www.project-syndicate.org/commentary/us-skilled-immi...

TIL: JS modelled Luggnagg on 蓬莱 (& thus struldbrugs on Tensens??? )

Edit: my oftcited dream of future days took place in a cavernous, subtidal (glass of scifi strength) shopping mall (consumerist pleasure dome) of the same (near) future..

On Jeju island

Edit: really appreciated WvO recording his early hopes.. have seen undergrads doing this, but a doc? a first for me!

https://www.weizmann.ac.il/mcb/alon/sites/mcb.alon/files/use...

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