2024/11/14

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2024-11-14 17:37:19 +0100Digit(~user@user/digit) (Ping timeout: 265 seconds)
2024-11-14 17:37:00 +0100Digitteknohippie(~user@user/digit) Digit
2024-11-14 17:34:26 +0100 <haskellbridge> <Bowuigi> It turns out that first class labels are just Proxy on a kind ranging over every possible label
2024-11-14 17:33:44 +0100 <haskellbridge> <Bowuigi> Now that everything is solved, it's time to move to something else
2024-11-14 17:21:27 +0100 <geekosaur> llvm still lacks support for pre-CPSed code
2024-11-14 17:20:48 +0100aljazmc(~aljazmc@user/aljazmc) aljazmc
2024-11-14 17:19:31 +0100 <tomsmeding> :)
2024-11-14 17:19:01 +0100tromp(~textual@92-110-219-57.cable.dynamic.v4.ziggo.nl)
2024-11-14 17:16:39 +0100 <EvanR> ok
2024-11-14 17:16:35 +0100 <tomsmeding> EvanR: it definitely is not
2024-11-14 17:16:16 +0100 <Inst> probably MY skill issue :(
2024-11-14 17:16:14 +0100 <EvanR> is llvm not the default now anyway
2024-11-14 17:14:34 +0100 <bailsman> Inst: I compiled my benchmark with -O2 -fllvm. Does not seem meaningfully different. Is -O2 the wrong optimization level?
2024-11-14 17:12:36 +0100 <Inst> try compile with -fllvm
2024-11-14 17:12:30 +0100 <lambdabot> Unknown command, try @list
2024-11-14 17:12:30 +0100 <Inst> @bailsman
2024-11-14 17:11:19 +0100 <EvanR> in any case idiomatic haskell is a starting point for getting into the weeds for optimization
2024-11-14 17:10:34 +0100 <EvanR> not necessarily, sometimes idiomatic haskell is faster
2024-11-14 17:10:03 +0100 <bailsman> If you write idiomatic haskell, you get as-slow-as-you-would-expect, if you try to write in-place code, you get way-slower-than-you-would-expect.
2024-11-14 17:09:25 +0100 <EvanR> in the case of arrays, for lookup tables
2024-11-14 17:09:22 +0100 <bailsman> I agree with your conclusion - stop trying to be clever and just learn what idiomatic haskell code looks like.
2024-11-14 17:08:53 +0100 <EvanR> but as a looping mechanism
2024-11-14 17:08:44 +0100 <EvanR> in the case of list, usually not as a data structure
2024-11-14 17:08:09 +0100 <EvanR> list and arrays in haskell are both good for certain purposes
2024-11-14 17:07:25 +0100 <EvanR> "they are both called list" isn't that inspiring
2024-11-14 17:06:59 +0100 <EvanR> the C version of linked list is just a bad thing to compare to haskell list unless you are careful to emulate what the haskell version did
2024-11-14 17:06:20 +0100 <bailsman> To me the fact that the Haskell Vector is ~100ms, Haskell map is ~25ms, C allocate-new-linked-list-and-copy version is ~15ms, C array in place is ~2ms is suggestive of the fact that indeed allocating a list is slow, and it's indeed what Haskell is doing, but it's still better than trying to do an array in Haskell.
2024-11-14 17:06:10 +0100 <EvanR> before claiming stuff about what stuff compiles to you should check it
2024-11-14 17:05:01 +0100 <EvanR> but the specific reasons are off
2024-11-14 17:04:50 +0100 <EvanR> "straight list processing and immutable structures are probably better in haskell than C-like mutable array munging" though is what I've been saying for days
2024-11-14 17:03:44 +0100 <geekosaur> gc only gets involved when the pointer reaches the end of the nursery
2024-11-14 17:03:31 +0100 <geekosaur> the nursery/gen 0 is a bump-pointer allocator
2024-11-14 17:03:20 +0100 <geekosaur> not magic
2024-11-14 17:03:13 +0100 <bailsman> I agree - I'm not really sure. Some GC magic probably. But the point is that it's builtin and optimized, so it's much faster than trying to emulate in-place updates, which compiles to a morass of work and not 5 asm instructions like the c version.
2024-11-14 17:02:06 +0100 <geekosaur> because it's probably not what actually happens
2024-11-14 17:01:56 +0100 <geekosaur> bailsman, what do you think is going on during an allocation?
2024-11-14 17:01:22 +0100 <EvanR> yes it is
2024-11-14 17:01:08 +0100 <bailsman> No it isn't.
2024-11-14 17:00:57 +0100 <EvanR> allocating nodes in haskell is much faster
2024-11-14 17:00:38 +0100 <EvanR> are you allocating nodes with malloc
2024-11-14 17:00:31 +0100 <EvanR> that's... not going to be an apples to apples comparison
2024-11-14 17:00:30 +0100 <bailsman> So I think I'm concluding that map is "the best you can do in haskell" because it's optimized and a builtin, and any attempt to do in place algorithms is just going to be massively slow.
2024-11-14 17:00:06 +0100 <bailsman> To test my theory, I wrote a C version of the benchmark. Updating a linked list by allocating nodes one by one and copying over the values takes 14ms, approximately as long as Haskell takes to do map. Updating 1M records inplace in an array takes 2ms.
2024-11-14 16:59:12 +0100 <geekosaur> and the tree example is probably closer to your actual AST than a list zipper example would be
2024-11-14 16:58:51 +0100 <geekosaur> even if it won't work with your structure as is, the wiki page I pointed you to earlier describes what you can do with a zipper
2024-11-14 16:58:42 +0100lortabac(~lortabac@2a01:e0a:541:b8f0:55ab:e185:7f81:54a4) (Quit: WeeChat 4.4.2)
2024-11-14 16:57:58 +0100 <geekosaur> you can do anything to the focused node including remove or replace it, and moving the zipper will reknit the tree
2024-11-14 16:57:30 +0100 <ph88> ok cool, thanks geekosaur !
2024-11-14 16:57:24 +0100 <geekosaur> that'd be a zipper
2024-11-14 16:57:24 +0100 <ph88> can zipper do this too ?