2026/04/09

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2026-04-09 12:36:32 +0000 <merijn> Milan_Vanca: If you're comfortable with C and some assembly I've always found that STG paper rather enlightening
2026-04-09 12:35:53 +0000 <Milan_Vanca> merijn: Mostly procedural ones. Haskell is my first attempt at FP
2026-04-09 12:34:38 +0000 <merijn> i.e. what languages are you experienced with, etc.?
2026-04-09 12:34:21 +0000 <merijn> Milan_Vanca: What's your background?
2026-04-09 12:31:20 +0000tremon(~tremon@83.80.159.219) tremon
2026-04-09 12:28:07 +0000 <Milan_Vanca> Ty all :) I am gonna also read that link
2026-04-09 12:27:33 +0000 <ski> Milan_Vanca ^
2026-04-09 12:27:30 +0000 <lambdabot> strictness-guarded-recursion>
2026-04-09 12:27:30 +0000 <lambdabot> nfshost.com/articles/lazy-eval.html>; "Laziness, strictness, guarded recursion" by bitemyapp at <https://github.com/bitemyapp/learnhaskell/blob/master/specific_topics.md#user-content-laziness-
2026-04-09 12:27:30 +0000 <lambdabot> "Lazy Evaluation of Haskell" by monochrom at <http://www.vex.net/~trebla/haskell/lazy.xhtml>; "The Incomplete Guide to Lazy Evaluation (in Haskell)" by apfelmus in 2015-03-07 at <https://apfelmus.
2026-04-09 12:27:29 +0000 <ski> @where lazy
2026-04-09 12:25:32 +0000Googulator(~Googulato@94-21-172-213.pool.digikabel.hu)
2026-04-09 12:25:26 +0000qqq(~qqq@185.54.23.237) (Remote host closed the connection)
2026-04-09 12:25:24 +0000Googulator(~Googulato@94-21-172-213.pool.digikabel.hu) (Quit: Client closed)
2026-04-09 12:25:22 +0000CiaoSen(~Jura@p549cb690.dip0.t-ipconnect.de) (Ping timeout: 248 seconds)
2026-04-09 12:24:05 +0000 <merijn> a thunk is just "some computation that unfolds into a (sub)graph" and evaluation is "collapsing a graph into a result"
2026-04-09 12:22:33 +0000 <merijn> Milan_Vanca: Eventually as evaluation procedes parts of the original graph become unreachable (and thus eligible for GC)
2026-04-09 12:22:03 +0000 <merijn> refers to the result (regardless of how you reach x)
2026-04-09 12:21:57 +0000 <merijn> Milan_Vanca: basically we start out with a graph of expressions with main as root, which references x and 'one_hour_long', where 'one_hour_long' in turn also references x (which is a subgraph of '4' '+' and '1'), as code gets evaluated these graphs expand and collapse as we force new computation. Starting to evaluate 'x' first materialises this subgraph of 4+1, once that evaluation is complete 'x' just
2026-04-09 12:21:16 +0000uli-fem(~uli-fem@115.128.112.118)
2026-04-09 12:19:55 +0000 <merijn> Milan_Vanca: No
2026-04-09 12:19:50 +0000 <Milan_Vanca> Does it matter if X is defined in another module?
2026-04-09 12:19:49 +0000 <merijn> Milan_Vanca: It helps to think of a haskell program as a data structure that is mutated
2026-04-09 12:16:35 +0000synchromesh(~john@2406:5a00:2412:2c00:e029:fa8c:cb38:398f) synchromesh
2026-04-09 12:16:05 +0000synchromesh(~john@2406:5a00:2412:2c00:8174:9ae9:efe0:c152) (Read error: Connection reset by peer)
2026-04-09 12:14:56 +0000 <Milan_Vanca> It knows it can reuse the same x even when it is in different function
2026-04-09 12:14:28 +0000 <Milan_Vanca> So x is computed once and kept for first 30 mins..hmmmm.. interesting.
2026-04-09 12:12:47 +0000 <merijn> Milan_Vanca: 'x' becomes unreachable (an thus GC-able) after the first 30 minutes elapse
2026-04-09 12:12:16 +0000 <merijn> Milan_Vanca: Once the heap is full and GC is triggered it copies all live data (that is, data that is still reachable from the currently evaluating code) and copies that to a new heap. Then the old heap is reset
2026-04-09 12:12:13 +0000 <Milan_Vanca> Guyz.. what about this example https://paste.tomsmeding.com/TvkbD7xi
2026-04-09 12:11:36 +0000 <merijn> Milan_Vanca: Basically, GHC uses a "copy & compact" GC strategy. Which means it only cares (and scales in) live data
2026-04-09 12:10:58 +0000 <Milan_Vanca> I am aware of GC and their purpose.. and all these questions stem from this fact :)
2026-04-09 12:10:29 +0000 <mauke> :-)
2026-04-09 12:10:24 +0000 <merijn> mauke: Well, if you wanna be pedantic it's "no longer makes unavailable for release" ;)
2026-04-09 12:10:10 +0000 <mauke> haskell doesn't do timely destruction
2026-04-09 12:10:09 +0000machinedgod(~machinedg@d172-219-48-230.abhsia.telus.net) machinedgod
2026-04-09 12:09:58 +0000 <mauke> s/releases/makes available for release/
2026-04-09 12:09:38 +0000 <merijn> Milan_Vanca: But that's pretty much how it works in any garbage collected languages, that's not really specific to Haskell :)
2026-04-09 12:09:12 +0000 <merijn> correct
2026-04-09 12:09:04 +0000 <Milan_Vanca> I gues compiler sees that x is not used after one_hour_long and so releases it as soon as it finish printing of x?
2026-04-09 12:08:02 +0000 <Milan_Vanca> Sorry to bother you with these stupid questions but I have found no tutorial on this matter.
2026-04-09 12:07:44 +0000uli-fem(~uli-fem@115.128.112.118) (Ping timeout: 268 seconds)
2026-04-09 12:07:42 +0000 <Milan_Vanca> Will https://paste.tomsmeding.com/XLBvdfd1 will x be in memory while one_hour_long computation runs?
2026-04-09 12:05:08 +0000 <tomsmeding> here x is a global variable, so it never goes out of scope, so it lives forever (until the GC decides that it's pointless keeping it around because nothing references it any more)
2026-04-09 12:04:39 +0000 <tomsmeding> on a higher level: x is a monomorphic variable, so its value will live (once computed) until it goes out of scope -- or potentially for even longer if GHC decides so
2026-04-09 12:04:37 +0000 <merijn> mauke: It's a CAF, those can be GCed just fine if nothing references them anymore
2026-04-09 12:04:13 +0000 <merijn> mauke: Yes
2026-04-09 12:03:50 +0000 <tomsmeding> they can be, yes
2026-04-09 12:03:43 +0000 <mauke> are those ever released?
2026-04-09 12:03:37 +0000 <mauke> also, x is a global variable