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submitted 1 week ago* (last edited 1 week ago) by [email protected] to c/[email protected]

What I think in addition to what Atkinso writes: If you just strip arbitrary bytes that happen to be equal in value to the numeric value of ASCII control characters or whitespace, how can you be sure that you don't destroy valid non-whitespace unicode symbols?

You can't! This will work only of you have actually ASCII input.

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[-] [email protected] 6 points 1 week ago* (last edited 1 week ago)

The link is broken. Looks like code was accidentally pasted there.

https://lukasatkinson.de/2025/net-negative-cursor/%20%20%20%20let%20mut%20bytes%20=%20vec![0u8;%20len%20as%20usize];%20%20%20%20buf.read_exact(&mut%20bytes)?%3B++++++++%2F%2F+Sanitize+control+characters+++++let+sanitized_bytes%3A+Vec%3Cu8%3E+=+bytes.into_iter%28%29+++++++++.filter%28%7C&b%7C+b+%3E=+32+%7C%7C+b+%3D%3D+9+%7C%7C+b+%3D%3D+10+%7C%7C+b+%3D%3D+13%29+%2F%2F+Allow+space%2C+tab%2C+newline%2C+carriage+return++++.collect%28%29%3B

404 Page Not Found
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Cleaned up link: https://lukasatkinson.de/2025/net-negative-cursor/

[-] [email protected] 2 points 1 week ago

Thanks, I fixed it!

[-] [email protected] 3 points 1 week ago

Not a coder but I grasped enough.

Lastly, I'd like to know where the AI got the idea from. Sounds like pizza glue.

[-] [email protected] 2 points 1 week ago

I don't think this is a very interesting article. We already know AI suggests nonsense a lot of the time. That in no way demonstrates that it is net-negative. In my experience it's a net positive even accounting for the times it gets things wrong.

Yes you do have to review its code closely. News at 10.

It is kind of funny that they picked an example where it made an obvious mistake for their hero image though.

[-] [email protected] 0 points 1 week ago

let mut bytes = vec![0u8; len as usize];
    buf.read_exact(&mut bytes)?;

// Sanitize control characters
let sanitized_bytes: Vec<u8> = bytes.into_iter()
    .filter(|&b| b >= 32 || b == 9 || b == 10 || b == 13) // Allow space, tab, newline, carriage return
    .collect();


This implicitly, and wrongly, swaps the interpretation of the input from UTF8 text to pure ASCII.

[-] [email protected] 6 points 1 week ago

In UTF8, all bytes that are not an ASCII character have the high bit set.

[-] [email protected] 1 points 1 week ago

This person Unicodes

[-] [email protected] -2 points 1 week ago

You are right with this. But still, in Rust, a vector of u8 is different from a sequence of unicode characters. This would not work in Python3 either, while it'd work in Python2.

[-] [email protected] 2 points 1 week ago* (last edited 1 week ago)

~~yeah it's incorrect bc it destroys multibyte characters, but~~ no idea what you're saying about u8 being a different type from unicode. the original code was reading bytes and converting them too? the typing isn't the issue, you can still store utf8 as a series of bytes

[-] [email protected] 1 points 1 week ago

it's incorrect bc it destroys multibyte characters

It doesn't. As the poster two levels up said, all bytes that don't represent an ASCII character have the high bit set, even the follow-up bytes in multibyte sequences. So the condition b >= 32 will match and preserve them.

[-] [email protected] 4 points 1 week ago

yeah fair enough. that wasn't really my point and I wasn't paying attention

[-] [email protected] 1 points 1 week ago

No, the filter is correct even for UTF-8. Any ASCII character is exactly unchanged in UTF-8 (part of the reason it is popular). Since this code only filters out ASCII characters it works fine with ASCII or UTF-8.

this post was submitted on 01 Jun 2025
24 points (90.0% liked)

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