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

(mail.python.org)
2024 points randlet | 4 comments | 12 Jul 18 15:22 UTC | HN request time: 0.668s | 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/

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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.

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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!"

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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.
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1. kelnos ◴[12 Jul 18 18:05 UTC] No.17517115[source]▶
Because assignment is an expression. It has nothing specifically to do with the position being a conditional.

Conditionals need an expression, and assignment fits the bill, so it works.

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2. KSteffensen ◴[12 Jul 18 19:58 UTC] No.17518108[source]▶
Why is assignment an expression and not a statement? Why should an assignment evaluate to a value?
3. TooBrokeToBeg ◴[12 Jul 18 22:36 UTC] No.17519195[source]▶
> Because assignment is an expression. It has nothing specifically to do with the position being a conditional.

No, but it has a lot to do with the way humans write code. This is the source of the bug, not the logic. eg Why bother having whitespace that the compiler can't use (typically)? Human readability.

The concession to not take into account human failing, is pathological.

4. hinkley ◴[13 Jul 18 02:30 UTC] No.17520103[source]▶
The other partial fix is to stop allowing truthy conditionals. Only allow Boolean values and the only time you it wrong is when you’re assigning to booleans.