You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: iris.rs
    path of file: ./repos/itertools/examples
    
    the code of the file until where you have to start completion: ///
/// This example parses, sorts and groups the iris dataset
/// and does some simple manipulations.
///
/// Iterators and itertools functionality are used throughout.
use itertools::Itertools;
use std::collections::HashMap;
use std::iter::repeat;
use std::num::ParseFloatError;
use std::str::FromStr;

static DATA: &str = include_str!("iris.data");

#[derive(Clone, Debug)]
struct Iris {
    name: String,
    data: [f32; 4],
}

#[derive(Clone, Debug)]
enum ParseError {
    Numeric(ParseFloatError),
    Other(&'static str),
}

impl From<ParseFloatError> for ParseError {
    fn from(err: ParseFloatError) -> Self {
        Self::Numeric(err)
    }
}

/// Parse an Iris from a comma-separated line
impl FromStr for Iris {
    type Err = ParseError;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let mut iris = Self {
            name: "".into(),
            data: [0.; 4],
        };
        let mut parts = s.split(',').map(str::trim);

        // using Iterator::by_ref()
        for (index, part) in parts.by_ref().take(4).enumerate() {
            iris.data[index] = part.parse::<f32>()?;
        }
        if let Some(name) = parts.next() {
            iris.name = name.into();
        } else {
            return Err(ParseError::Other("Missing name"));
        }
        Ok(iris)
    }
}

fn main() {
    // using Itertools::fold_results to create the result of parsing
    let irises = DATA
    
    
fn main() {
    // using Itertools::fold_results to create the result of parsing
    let irises = DATA
        .lines()
        .map(str::parse)
        .fold_ok(Vec::new(), |mut v, iris: Iris| {
            v.push(iris);
            v
        });
    let mut irises = match irises {
        Err(e) => {
            println!("Error parsing: {:?}", e);
            std::process::exit(1);
        }
        Ok(data) => data,
    };

    // Sort them and group them
    irises.sort_by(|a, b| Ord::cmp(&a.name, &b.name));

    // using Iterator::cycle()
    let mut plot_symbols = "+ox".chars().cycle();
    let mut symbolmap = HashMap::new();

    // using Itertools::chunk_by
    for (species, species_chunk) in &irises.iter().chunk_by(|iris| &iris.name) {
        // assign a plot symbol
        symbolmap
            .entry(species)
            .or_insert_with(|| plot_symbols.next().unwrap());
        println!("{} (symbol={})", species, symbolmap[species]);

        for iris in species_chunk {
            // using Itertools::format for lazy formatting
            println!("{:>3.1}", iris.data.iter().format(", "));
        }
    }

    // Look at all combinations of the four columns
    //
    // See https://en.wikipedia.org/wiki/Iris_flower_data_set
    //
    let n = 30; // plot size
    let mut plot = vec![' '; n * n];

    // using Itertools::tuple_combinations
    for (a, b) in (0..4).tuple_combinations() {
        println!("Column {} vs {}:", a, b);

        // Clear plot
        //
        // using std::iter::repeat;
        // using Itertools::set_from
        plot.iter_mut().set_from(repeat(' '));

        // using Itertools::minmax
        let min_max = |data: &[Iris], col| {
            data.iter()
                .map(|iris| iris.data[col])
                .minmax()
                .into_option()
                .expect("Can't find min/max of empty iterator")
        };
        let (min_x, max_x) = min_max(&irises, a);
        let (min_y, max_y) = min_max(&irises, b);

        // Plot the data points
        let round_to_grid = |x, min, max| ((x - min) / (max - min) * ((n - 1) as f32)) as usize;
        let flip = |ix| n - 1 - ix; // reverse axis direction

        for iris in &irises {
            let ix = round_to_grid(iris.data[a], min_x, max_x);
            let iy = flip(round_to_grid(iris.data[b], min_y, max_y));
            plot[n * iy + ix] = symbolmap[&iris.name];
        }

        // render plot
        //
        // using Itertools::join
        for line in plot.chunks(n) {
            println!("{}", line.iter().join(" "))
        }
    }
}