[#111712] [Ruby master Feature#19322] Support spawning "private" child processes — "kjtsanaktsidis (KJ Tsanaktsidis) via ruby-core" <ruby-core@...>
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14 messages
2023/01/07
[ruby-core:111898] [Ruby master Feature#19245] Strict mode for Array#pack that doesn't silently truncate numbers that are too large for the given directive
From:
"matz (Yukihiro Matsumoto) via ruby-core" <ruby-core@...>
Date:
2023-01-19 06:19:03 UTC
List:
ruby-core #111898
Issue #19245 has been updated by matz (Yukihiro Matsumoto).
I don't think it would be default, but adding `strict:` (or any other keyword argument) is OK for me.
Matz.
----------------------------------------
Feature #19245: Strict mode for Array#pack that doesn't silently truncate numbers that are too large for the given directive
https://bugs.ruby-lang.org/issues/19245#change-101316
* Author: byroot (Jean Boussier)
* Status: Open
* Priority: Normal
----------------------------------------
```ruby
>> [256].pack("C").unpack1("C")
=> 0
>> [257].pack("C").unpack1("C")
=> 1
```
This is specified:
```ruby
it "encodes the least significant 32 bits of a negative number" do
[ [[-0x0000_0021], "\xdf\xff\xff\xff"],
[[-0x0000_4321], "\xdf\xbc\xff\xff"],
[[-0x0065_4321], "\xdf\xbc\x9a\xff"],
[[-0x7865_4321], "\xdf\xbc\x9a\x87"]
].should be_computed_by(:pack, pack_format())
end
```
But not documented in `Array#pack`.
I think that in many case this may lead to silent bugs.
### Possible solutions
We could have a strict version of `pack`, either `pack(template, strict: true)` or `pack!(template)`.
Or alternatively if we think this is never a desired behavior, we could change `pack` to first warn on truncation and later raise.
--
https://bugs.ruby-lang.org/
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