Error("invalid type: map, expected a sequence", line: 1, column: 1),

   Error("invalid type: map, expected a sequence", line: 1, column: 1),

    0{  
    symbol  "ETHBTC"
    priceChange "0.00068700"
    priceChangePercent  "0.874"
    weightedAvgPrice    "0.07908580"
    prevClosePrice  "0.07864600"
    lastPrice   "0.07933400"
    lastQty "0.18460000"
    bidPrice    "0.07933400"
    bidQty  "4.49640000"
    askPrice    "0.07933500"
    askQty  "54.13430000"
    openPrice   "0.07864700"
    highPrice   "0.07945000"
    lowPrice    "0.07846100"
    volume  "56892.20330000"
    quoteVolume "4499.36548634"
    openTime    1662288072375
    closeTime   1662374472375
    firstId 369847410
    lastId  370015037
    count   167628
    }

My request function makes a cURL request and receives the above JSON. I then use serde_json to deserialize the JSON>. Please help in solving this issue

main.rs

use serde::Deserialize;
use std::error::Error;

#[derive(Deserialize, Debug)]
struct Peers {
    num: Vec<Peer>,
}

#[derive(Deserialize, Debug)]
struct Peer {
    symbol: String,
    count: u32,
}

fn get_node(url: &str) -> Result<Peer, Box<dyn Error>> {
    let response = ureq::get(url).call()?.into_string()?;
    let node: Peers = serde_json::from_str(&response)?;

    dbg!(node);
    todo!()
}

fn main() {
    let url = "https://api.binance.com/api/v1/ticker/24hr";
    let num = get_node(url);
    dbg!(num);
    todo!()
}

I'm getting the following error message in my terminal

       num = Err(
            Error("invalid type: map, expected a sequence", line: 1, column: 1),
        )
        thread 'main' panicked at 'not yet implemented',
        note: run with `RUST_BACKTRACE=1` environment variable to display a

I'm certain I'm making a stupid mistake in deserializing my JSON structure, I've tried a number of permutations and combinations but I couldn't get anything to work. Please help me solving this issue in Rust

Solution

Your issue is that you're trying to deseralize the top level array ([{...}, {..}]) into a struct (Peers).

You noted in your struct that it should be a vec, which is the right thing to deserialize into, so you're close. All you need to do is change your:

let node : Peers = serde_json::from_str(&response)?;

into

let node : Vec<Peer> = serde_json::from_str(&response)?;

If you want to keep your Peers struct in the function, you could do something like:

let peers = Peers {
    num: serde_json::from_str(&response)?,
};

By the way ureq has a tool that will simplify your usage of serde_json.