2025/05/12

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2025-05-12 03:49:14 +0200hughjfchen(~hughjfche@vmi2417424.contaboserver.net) hughjfchen
2025-05-12 03:48:44 +0200hughjfch1(~hughjfche@vmi2417424.contaboserver.net) (Quit: WeeChat 4.4.3)
2025-05-12 03:38:05 +0200ljdarj(~Thunderbi@user/ljdarj) (Ping timeout: 265 seconds)
2025-05-12 03:11:49 +0200xff0x(~xff0x@2405:6580:b080:900:42e0:bce1:22f1:2695) (Ping timeout: 276 seconds)
2025-05-12 03:06:59 +0200ljdarj(~Thunderbi@user/ljdarj) ljdarj
2025-05-12 03:05:13 +0200ljdarj(~Thunderbi@user/ljdarj) (Ping timeout: 265 seconds)
2025-05-12 03:01:11 +0200siliconcritters(~siliconcr@syn-068-188-168-151.res.spectrum.com) (Quit: siliconcritters)
2025-05-12 02:45:55 +0200jmcantrell(~weechat@user/jmcantrell) jmcantrell
2025-05-12 02:42:05 +0200meinside(uid24933@id-24933.helmsley.irccloud.com) meinside
2025-05-12 02:39:31 +0200 <EvanR> so ghc must do none of the above
2025-05-12 02:38:31 +0200 <EvanR> it seems to me that environment is real solution only if stuff in the environment doesn't have free variables, like in eager evaluation
2025-05-12 02:35:14 +0200xff0x(~xff0x@2405:6580:b080:900:42e0:bce1:22f1:2695)
2025-05-12 02:34:34 +0200califax(~califax@user/califx) califx
2025-05-12 02:32:29 +0200 <monochrom> I think Scheme hygienic macros use the alpha-convert way.
2025-05-12 02:32:23 +0200califax(~califax@user/califx) (Remote host closed the connection)
2025-05-12 02:31:57 +0200 <monochrom> The pros do one of. They do one of: numbering, environment, alpha-convert lambdas to fresh vars before substitute (e.g., rewrite (\x y -> x + y) to (\uuid1934 uuid3141 -> uuid1934 + uuid3141))
2025-05-12 02:28:55 +0200 <monochrom> The mistake happens if you really do what you tell beginners: substitute. :)
2025-05-12 02:27:33 +0200 <monochrom> Environment is also a way to be invulnerable.
2025-05-12 02:21:36 +0200Tuplanolla(~Tuplanoll@91-159-69-59.elisa-laajakaista.fi) (Quit: Leaving.)
2025-05-12 02:21:30 +0200xff0x(~xff0x@2405:6580:b080:900:d755:12f8:638d:5cf9) (Client Quit)
2025-05-12 02:18:44 +0200xff0x(~xff0x@2405:6580:b080:900:d755:12f8:638d:5cf9)
2025-05-12 02:18:05 +0200xff0x(~xff0x@2405:6580:b080:900:9d68:c704:b1b0:2e99) (Ping timeout: 260 seconds)
2025-05-12 02:09:28 +0200j1n37(~j1n37@user/j1n37) (Ping timeout: 272 seconds)
2025-05-12 02:08:41 +0200j1n37-(~j1n37@user/j1n37) j1n37
2025-05-12 02:08:32 +0200 <EvanR> (in the first example one of the y and in this example the z are free so wouldn't get IDs afaiui)
2025-05-12 02:07:27 +0200 <EvanR> so when you convert from debruijn back to named variables you better use unique names
2025-05-12 02:06:09 +0200 <EvanR> yields an identity function instead of a constant function
2025-05-12 02:04:55 +0200 <EvanR> (\x y -> \z -> x) z
2025-05-12 02:03:04 +0200weary-traveler(~user@user/user363627) (Remote host closed the connection)
2025-05-12 02:02:20 +0200 <EvanR> I'm probably wrong about my observation, but using your example I'll show what I mean, (\x y -> x + y) y z, evaluate x+y in environment [x=>y, y=>z], y + z. I'll see if I can fix the example
2025-05-12 02:01:52 +0200sajenim(~sajenim@user/sajenim) sajenim
2025-05-12 01:55:41 +0200 <monochrom> Template Haskell gives you two functions for creating names, so that you can choose whether you want variable capture or not per variable. (There are legit use cases when you want it.)
2025-05-12 01:53:44 +0200machinedgod(~machinedg@d108-173-18-100.abhsia.telus.net) (Ping timeout: 252 seconds)
2025-05-12 01:53:25 +0200 <monochrom> Lisp macros, at least for old Lisp, are also vulnerable. When the Scheme people say "hygienic macros" they mean that macro expansion takes care not to make that mistake again.
2025-05-12 01:50:39 +0200 <monochrom> Too lazy to read that paper, but here is a common mistake ("variable capture") when using names: ((\x y -> x + y) y) z = (\y -> y + y) z = z + z instead of y + z. De Bruijn numbering (or other numbering schemes) are not vulnerable to this mistake, the two "y"s have different IDs.
2025-05-12 01:47:48 +0200siliconcritters(~siliconcr@syn-068-188-168-151.res.spectrum.com)
2025-05-12 01:39:12 +0200ttybitnik(~ttybitnik@user/wolper) (Quit: Fading out...)
2025-05-12 01:32:16 +0200zdercti^(~zdercti@50.168.231.214)
2025-05-12 01:31:56 +0200sprotte24(~sprotte24@p200300d16f052e00b01ecb3cf5e5d8f9.dip0.t-ipconnect.de) (Quit: Leaving)
2025-05-12 01:18:40 +0200bitdex(~bitdex@gateway/tor-sasl/bitdex) bitdex
2025-05-12 01:18:09 +0200bitdex(~bitdex@gateway/tor-sasl/bitdex) (Remote host closed the connection)
2025-05-12 01:11:03 +0200merijn(~merijn@host-vr.cgnat-g.v4.dfn.nl) merijn
2025-05-12 00:59:33 +0200merijn(~merijn@host-vr.cgnat-g.v4.dfn.nl) (Ping timeout: 265 seconds)
2025-05-12 00:56:49 +0200acidjnk(~acidjnk@p200300d6e71c4f78180f209d949bdd6b.dip0.t-ipconnect.de) (Ping timeout: 248 seconds)
2025-05-12 00:43:28 +0200Lord_of_Life_Lord_of_Life
2025-05-12 00:42:14 +0200Lord_of_Life(~Lord@user/lord-of-life/x-2819915) (Ping timeout: 252 seconds)
2025-05-12 00:42:05 +0200Lord_of_Life_(~Lord@user/lord-of-life/x-2819915) Lord_of_Life
2025-05-12 00:41:16 +0200 <EvanR> must be for inevitable alpha conversion
2025-05-12 00:17:00 +0200weary-traveler(~user@user/user363627) user363627
2025-05-12 00:14:32 +0200xff0x(~xff0x@2405:6580:b080:900:9d68:c704:b1b0:2e99)