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“I'm basically giving myself a permanent vacation from being BDFL”

(mail.python.org)
2024 points randlet | 3 comments | 12 Jul 18 15:22 UTC | HN request time: 0.642s | source
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js2 ◴[12 Jul 18 16:15 UTC] No.17516019[source]▶
Background ("PEP 572 and decision-making in Python"):

https://lwn.net/Articles/757713/

replies(2): >>17516132 #>>17516693 #
jcelerier ◴[12 Jul 18 16:26 UTC] No.17516132[source]▶
> The problem with the C-style of assignments is that it leads to this classic error: if(x = 0) {...}

yeah, if you code on 20 years old compilers with no warnings. GCC 4.1 warns about this (with -Wall) and Clang 3.4 warns about this too, without any warning flag.

replies(4): >>17516174 #>>17516220 #>>17517715 #>>17518178 #
Waterluvian ◴[12 Jul 18 16:29 UTC] No.17516174[source]▶
I think that having strong opinions on how others should be developing software is how communities become toxic like this.

"Shooting yourself in the foot is your fault for not using a linter that detects accidental misuse of assignment!"

replies(3): >>17516217 #>>17516742 #>>17516875 #
TooBrokeToBeg ◴[12 Jul 18 17:24 UTC] No.17516742[source]▶
I'm still puzzled to why would a compiler allow assignment in an explicit conditional (outside of loop syntax). It's like a baked-in blindspot that most people just want to ignore for some reason. Some languages actually guard against this well enough (eg Kotlin) and say "don't". Even with guards in place, it's not all that complicated to work around in the edge cases where you might want to do it.
replies(5): >>17517091 #>>17517115 #>>17519127 #>>17519910 #>>17519933 #
shakna ◴[12 Jul 18 22:25 UTC] No.17519127[source]▶
It's handy in C for guarding parts of the language, as you often have to check return values anyway.

    if(malloc(10000 * sizeof foo) == NULL) {
      // Error processing
    } // No need for an else branch here.
replies(1): >>17519309 #
1. the-dude ◴[12 Jul 18 22:56 UTC] No.17519309[source]▶
Missing assingment.
replies(1): >>17519481 #
2. shakna ◴[12 Jul 18 23:34 UTC] No.17519481[source]▶

    int success = NULL;

    if(success = malloc(...)) {
    }
    if(success = malloc(...)) {
    }
    if(success = malloc(...)) {
    }
replies(1): >>17519737 #
3. slavik81 ◴[13 Jul 18 00:39 UTC] No.17519737[source]▶
That will result in undefined behaviour if the value returned by malloc is greater than INT_MAX. If you really need an integer, use intptr_t. But, generally it makes more sense to just use a pointer.

    char* p = NULL;
    if (p = malloc(...)) {
      ...
    }