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| Subject | Re: True == 1 weirdness |
| Date | Thu, 17 Sep 2015 17:26:54 -0400 |
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On Thu, Sep 17, 2015, at 16:24, Jussi Piitulainen wrote: > And I'm saying 'in', being truth-valued, is more like a comparison than > a proper binary operation that has its value in the same set as its two > arguments. The problem is that except for very specialized cases (strings), the two arguments are not (semantically, at least) in the same set as each other, either. It may be "more" like a comparison, but it's not *really* like either one. > Just trying to explain what I had in mind when I said that I feel that > 'in' is more at home with comparisons (where it is now) than with, hm, > arithmetic operations. Why does it have to be either one? I don't even think chaining should work for all *actual* comparison operations. Say you have this statement: (1) a < b = c <= d While it may *actually* mean this: (2) a < b and b = c and c <= d It *semantically* means this: (3) a < b and a < c and a < d and b = c and b <= d and c <= d The ones that are included logically imply the ones that are not, for any sane definition of these operators. And if your operators *aren't* sane, it's better to be explicit about what you are doing. It should not be applied to any combination of operations that cannot meaningfully be read as such a statement (e.g. mixing directions of less/greater comparisons, or including in, is not, or != at all), or to any values expected to have (2) not imply (3). It being *easier to implement* to have comparison operators be a single class and have chaining apply equally to all of them may be an excuse for the language to allow it, but it's certainly not an excuse for *actually* using it from a standpoint of good style and readability.
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True == 1 weirdness "Blake T. Garretson" <blake.garretson@gmail.com> - 2015-09-16 05:16 -0700
Re: True == 1 weirdness Jussi Piitulainen <harvesting@makes.email.invalid> - 2015-09-16 15:53 +0300
Re: True == 1 weirdness Chris Angelico <rosuav@gmail.com> - 2015-09-16 23:05 +1000
Re: True == 1 weirdness "Blake T. Garretson" <blake.garretson@gmail.com> - 2015-09-16 06:14 -0700
Re: True == 1 weirdness Random832 <random832@fastmail.com> - 2015-09-16 10:03 -0400
Re: True == 1 weirdness Steven D'Aprano <steve@pearwood.info> - 2015-09-17 03:24 +1000
Re: True == 1 weirdness Random832 <random832@fastmail.com> - 2015-09-16 13:36 -0400
Re: True == 1 weirdness "Sven R. Kunze" <srkunze@mail.de> - 2015-09-16 19:57 +0200
Re: True == 1 weirdness Ian Kelly <ian.g.kelly@gmail.com> - 2015-09-16 11:57 -0600
Re: True == 1 weirdness Chris Angelico <rosuav@gmail.com> - 2015-09-17 00:26 +1000
Re: True == 1 weirdness Marko Rauhamaa <marko@pacujo.net> - 2015-09-16 19:16 +0300
Re: True == 1 weirdness "Sven R. Kunze" <srkunze@mail.de> - 2015-09-16 18:37 +0200
Re: True == 1 weirdness Marko Rauhamaa <marko@pacujo.net> - 2015-09-16 19:53 +0300
Re: True == 1 weirdness Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-09-17 18:30 +1200
Re: True == 1 weirdness Random832 <random832@fastmail.com> - 2015-09-16 12:57 -0400
Re: True == 1 weirdness Steven D'Aprano <steve@pearwood.info> - 2015-09-17 03:39 +1000
Re: True == 1 weirdness Marko Rauhamaa <marko@pacujo.net> - 2015-09-16 20:42 +0300
Re: True == 1 weirdness Emile van Sebille <emile@fenx.com> - 2015-09-16 11:46 -0700
Re: True == 1 weirdness Grant Edwards <invalid@invalid.invalid> - 2015-09-16 17:46 +0000
Re: True == 1 weirdness "Sven R. Kunze" <srkunze@mail.de> - 2015-09-16 20:13 +0200
Re: True == 1 weirdness Grant Edwards <invalid@invalid.invalid> - 2015-09-16 19:47 +0000
Re: True == 1 weirdness Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-16 21:25 +0100
Re: True == 1 weirdness Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-09-17 18:36 +1200
Re: True == 1 weirdness "Sven R. Kunze" <srkunze@mail.de> - 2015-09-16 23:05 +0200
Re: True == 1 weirdness Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-09-17 18:39 +1200
Re: True == 1 weirdness "Sven R. Kunze" <srkunze@mail.de> - 2015-09-17 22:46 +0200
Re: True == 1 weirdness Tim Chase <python.list@tim.thechases.com> - 2015-09-17 16:26 -0500
Re: True == 1 weirdness "Sven R. Kunze" <srkunze@mail.de> - 2015-09-17 23:52 +0200
Re: True == 1 weirdness Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-16 22:30 +0100
Re: True == 1 weirdness "Sven R. Kunze" <srkunze@mail.de> - 2015-09-17 00:15 +0200
Re: True == 1 weirdness Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-17 01:06 +0100
Re: True == 1 weirdness Steven D'Aprano <steve@pearwood.info> - 2015-09-17 11:33 +1000
Re: True == 1 weirdness Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-17 10:56 +0100
Re: True == 1 weirdness alister <alister.nospam.ware@ntlworld.com> - 2015-09-17 12:07 +0000
Re: True == 1 weirdness Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-17 13:27 +0100
Re: True == 1 weirdness Steven D'Aprano <steve@pearwood.info> - 2015-09-17 12:34 +1000
Re: True == 1 weirdness Chris Angelico <rosuav@gmail.com> - 2015-09-17 10:53 +1000
Re: True == 1 weirdness Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-09-17 18:42 +1200
Re: True == 1 weirdness Emile van Sebille <emile@fenx.com> - 2015-09-16 18:12 -0700
Re: True == 1 weirdness Tim Chase <python.list@tim.thechases.com> - 2015-09-16 18:10 -0500
Re: True == 1 weirdness "Sven R. Kunze" <srkunze@mail.de> - 2015-09-16 19:53 +0200
Re: True == 1 weirdness Marko Rauhamaa <marko@pacujo.net> - 2015-09-16 22:47 +0300
Re: True == 1 weirdness Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-16 21:29 +0100
Re: True == 1 weirdness Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-16 22:27 +0100
Re: True == 1 weirdness "Sven R. Kunze" <srkunze@mail.de> - 2015-09-16 19:23 +0200
Re: True == 1 weirdness Grant Edwards <invalid@invalid.invalid> - 2015-09-16 17:27 +0000
Re: True == 1 weirdness Emile van Sebille <emile@fenx.com> - 2015-09-16 10:41 -0700
Re: True == 1 weirdness Steven D'Aprano <steve@pearwood.info> - 2015-09-17 03:42 +1000
Re: True == 1 weirdness Grant Edwards <invalid@invalid.invalid> - 2015-09-16 17:44 +0000
Re: True == 1 weirdness Random832 <random832@fastmail.com> - 2015-09-16 13:55 -0400
Re: True == 1 weirdness Ian Kelly <ian.g.kelly@gmail.com> - 2015-09-16 11:55 -0600
Re: True == 1 weirdness Steven D'Aprano <steve@pearwood.info> - 2015-09-17 11:16 +1000
Re: True == 1 weirdness Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-16 21:22 +0100
Re: True == 1 weirdness Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-16 21:17 +0100
Re: True == 1 weirdness Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-09-17 18:24 +1200
Re: True == 1 weirdness Jussi Piitulainen <harvesting@makes.email.invalid> - 2015-09-17 10:06 +0300
Re: True == 1 weirdness Ian Kelly <ian.g.kelly@gmail.com> - 2015-09-17 12:49 -0600
Re: True == 1 weirdness Jussi Piitulainen <harvesting@makes.email.invalid> - 2015-09-17 23:24 +0300
Re: True == 1 weirdness Random832 <random832@fastmail.com> - 2015-09-17 17:26 -0400
Re: True == 1 weirdness Marko Rauhamaa <marko@pacujo.net> - 2015-09-18 00:38 +0300
Re: True == 1 weirdness "Sven R. Kunze" <srkunze@mail.de> - 2015-09-17 23:49 +0200
Re: True == 1 weirdness Chris Angelico <rosuav@gmail.com> - 2015-09-18 12:03 +1000
Re: True == 1 weirdness Jussi Piitulainen <harvesting@makes.email.invalid> - 2015-09-18 10:10 +0300
Re: True == 1 weirdness Steven D'Aprano <steve@pearwood.info> - 2015-09-18 22:30 +1000
Re: True == 1 weirdness Chris Angelico <rosuav@gmail.com> - 2015-09-18 04:57 +1000
Re: True == 1 weirdness Jussi Piitulainen <harvesting@makes.email.invalid> - 2015-09-17 23:44 +0300
Re: True == 1 weirdness Tim Chase <python.list@tim.thechases.com> - 2015-09-16 09:38 -0500
Re: True == 1 weirdness Random832 <random832@fastmail.com> - 2015-09-16 11:40 -0400
Re: True == 1 weirdness Steven D'Aprano <steve@pearwood.info> - 2015-09-17 03:33 +1000
Re: True == 1 weirdness "Sven R. Kunze" <srkunze@mail.de> - 2015-09-16 19:41 +0200
Re: True == 1 weirdness Steven D'Aprano <steve@pearwood.info> - 2015-09-17 11:22 +1000
Re: True == 1 weirdness Random832 <random832@fastmail.com> - 2015-09-16 13:47 -0400
Re: True == 1 weirdness Grant Edwards <invalid@invalid.invalid> - 2015-09-16 17:52 +0000
Re: True == 1 weirdness Steven D'Aprano <steve@pearwood.info> - 2015-09-17 11:25 +1000
Re: True == 1 weirdness Random832 <random832@fastmail.com> - 2015-09-17 02:10 -0400
Re: True == 1 weirdness Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-09-17 12:29 +0000
Re: True == 1 weirdness Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-09-16 21:38 +0100
Re: True == 1 weirdness Random832 <random832@fastmail.com> - 2015-09-16 16:55 -0400
Re: True == 1 weirdness "Sven R. Kunze" <srkunze@mail.de> - 2015-09-16 23:03 +0200
Re: True == 1 weirdness jmp <jeanmichel@sequans.com> - 2015-09-21 14:01 +0200
Re: True == 1 weirdness jmp <jeanmichel@sequans.com> - 2015-09-16 15:08 +0200
Re: True == 1 weirdness "Blake T. Garretson" <blake.garretson@gmail.com> - 2015-09-16 06:17 -0700
Re: True == 1 weirdness Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-09-16 09:28 -0400
Re: True == 1 weirdness Chris Angelico <rosuav@gmail.com> - 2015-09-17 00:57 +1000
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