rust-lang/rust

Roman Proskuryakov

@kpp

Dec 09 2017 08:33 UTC

Aren't you bored with futures::sync::mpsc::channel(8) copypaste? I hate that magic number

Naja Melan

@najamelan

Dec 09 2017 14:46 UTC

Is there any more ergonomic way to write this?

fn key( path: &str ) -> Vec< String >
    {
        let mut components: Vec< String > = path.split( '/' ).map( |s| s.to_string() ).collect();

        // If present, remove the trailing empty string (which represents a trailing slash).
        // If it isn't removed a path without a trailing space will never match the same path with trailing space
        // Can't find a way to write this without the boolean without upsetting the borrow checker.
        //
        let mut trailing = false;

        {
            if let Some( s ) = components.last() {
            if s.is_empty()
            {
                trailing = true;
            }}
        }

        if trailing { components.pop(); }

        components
    }

The borrow checker won't let me pop without creating a bool in a separate scope

because components.last borrows the vector

This seems like a lot of boilerplate to express: "if the last string in the vec is empty, pop it"

Sean

@seanr707

Dec 09 2017 16:56 UTC

@najamelan What about this?

if match components.last() {
    Some(s) => s.is_empty(),
    _ => false,
} {
       components.pop();
}

Restioson

@Restioson

Dec 09 2017 19:25 UTC

@tanriol i might be able to rather have an enum which has Sized and Unsized variants

Thanks for the helpful info thought!

Naja Melan

@najamelan

Dec 09 2017 19:38 UTC

Also, I would prefer here to just use a slice, but that can't be returned from the method because it's size is not known at compile time, even though I declared the method inline.
@seanr707 Thanks alot, that works. Do I get it right that the match arguments is in the match scope (so the borrow is out of scope when the pop happens), where as an if expression belongs to the outer scope?

Michal 'vorner' Vaner

@vorner

Dec 09 2017 19:43 UTC

Hmm, cool :-|. I just got 100kB long error message.

Sean

@seanr707

Dec 09 2017 20:24 UTC

@najamelan I'm fairly new to the language but I believe so. What kind of error were you receiving before?

Nikita

@nikita-y

Dec 09 2017 22:39 UTC

hi there

i’ve got a problem. It seems that str::from_utf8 corrupts data

Denis Lisov

@tanriol

Dec 09 2017 22:41 UTC

Do you have a reproducible example?

Nikita

@nikita-y

Dec 09 2017 22:42 UTC

extern crate curl;
extern crate json;

use curl::easy::Easy;
use std::str;
use json::*;

fn main() {
    let query = build_qery();
    let mut easy = Easy::new();
    easy.url(query.as_str()).expect("Query error");

    let mut transfer = easy.transfer();
    let result = transfer.write_function(|data| {
        println!("{}", str::from_utf8(data).unwrap());
        //let temp_s = str::from_utf8(data).unwrap();
       // let parsed = json::parse(temp_s.expect("FFFFUCK");
        Ok(data.len())
    });
    result.expect("Transfer error");
    transfer.perform().expect("Transfer error")
}

fn build_qery() -> String {
    "https://api.darksky.net/forecast/6143f6925645b592e2ca57829537a30a/37.8267,-122.4233?units=si".to_owned()
}