Error Propagation in File Handling

Error propagation is a core concept in Rust that allows you to handle errors in a clean and structured way. Instead of having to handle each error manually on every step, you can easily use the ? operator to propagate errors to a higher level so that they can be handled in a single place.

In this challenge, you’ll use io::Error to represent potential issues when working with file I/O. This approach leverages Rust’s standard library for concise and idiomatic error handling.

Your Task

Your task is to implement a function that reads integers from a file, computes their sum, and gracefully propagates any errors using the ? operator.

Implement the function sum_integers_from_file:

Takes the file path as a parameter.
Reads the file line by line, assuming each line contains a single integer or invalid data.
Computes and returns the sum of all integers as a Result<i32, io::Error>.
Handles the following:
- If the file cannot be opened, propagate the io::Error.
- If a line cannot be parsed as an integer, propagate a custom io::Error with a meaningful message.

Requirements

Handle errors cleanly and propagate them using the ? operator.
For invalid lines, create an io::Error with io::ErrorKind::InvalidData.

Hints

If you're stuck, here are some hints to help you solve the challenge:

Click here to reveal hints

Use std::fs::File::open to open a file.
Use io::BufReader::new to read lines from the file.
Convert strings to integers with the str::parse method.
The io::Error::new function can create custom errors.
To create the error type we want for invalid numbers, you can do the following:
```
let error = io::Error::new(io::ErrorKind::InvalidData, "Invalid number");
```
To propagate an error, use the ? operator. e.g.
```
let file = File::open(file_path)?;
```

You can transform an error type to another error type by using the map_err method. e.g.

let num = num_str.parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;

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Solutions

Özgür

AyikOzgur

11 hours ago

4.93ms

96.16kb

use std::io;
use std::fs::File;
use std::io::BufReader;
use std::io::BufRead;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum: i32 = 0;
    for line in reader.lines() {
        let value: Result<i32, _> = line?.parse();
        match value {
            Ok(value_int) => { sum += value_int;}
            Err(_) => {return Err(io::Error::new(io::ErrorKind::InvalidData,  "Invalid number"));}
        }
    }
    return Ok(sum);
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Egu0

egu0

12 hours ago

4.59ms

96.16kb

use std::fs::File;
use std::io;
use std::io::{prelude::*, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let f: File = File::open(file_path)?;
    let reader = BufReader::new(f);
    let mut sum = 0;
    for line_result in reader.lines() {
        let line = line_result?; // Result<String, _>
        let num: Result<i32, std::num::ParseIntError> = line.as_str().parse::<i32>();
        if let Ok(n) = num {
            sum += n;
        } else {
            return Err(io::Error::new(io::ErrorKind::InvalidData, "Invalid number"));
        }
    }
    Ok(sum)
}
// Example usage

emiludenz

a day ago

4.51ms

96.16kb

use std::fs::File;
use std::io;
use std::io::{BufRead, BufReader, ErrorKind};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = File::open(file_path);
    let reader = BufReader::new(file?);
    let mut sum = 0;
    for line in reader.lines() {
        let num = line?.parse::<i32>();
        if num.is_err() {
            return Err(io::Error::new(
                ErrorKind::InvalidData,
                "Not a number".to_string(),
            ));
        }else{
            sum += num.unwrap();
        }
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

azmahflameheart

2 days ago

5.13ms

96.16kb

use std::io::{self, BufReader, BufRead};
use std::fs::File;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let buf_reader = BufReader::new(File::open(file_path)?);
    buf_reader.lines().try_fold(0, |sum, lines| {
        Ok(sum + lines?.parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number!"))?)
    })
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

LawisChen

5 days ago

5.38ms

87.38kb

use std::fs::read_to_string;
use std::io;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    Ok(read_to_string(file_path)?
        .lines()
        .map(|line| line.parse::<i32>().map_err(|_| io::ErrorKind::InvalidData))
        .collect::<Result<Vec<_>, _>>()?
        .into_iter()
        .fold(0, |acc, ele| acc + ele))
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

ffrie

6 days ago

5.43ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum : i32 = 0;
    for num_str in reader.lines() {
        sum += num_str?.parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Ramon Silva

rsilva1

7 days ago

4.62ms

96.17kb

use std::io::{self, BufReader, BufRead};
use std::fs::File;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let f = File::open(file_path)?;
    let mut numbers: Vec<i32> = vec![];
    for line in BufReader::new(f).lines() {
        let number = line?
            .parse::<i32>()
            .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "expected i32"))?;
        numbers.push(number);
    }
    Ok(numbers.into_iter().sum())
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

vqk-2003

7 days ago

4.45ms

96.16kb

use std::{ io, io::BufRead, fs };
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let f = fs::File::open(file_path)?;
    let mut sum = 0;
    for l in io::BufReader::new(f).lines() {
        sum += l?.parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

gtakacse

9 days ago

5.26ms

96.16kb

use std::{
    fs::File,
    io::{self, BufRead, BufReader},
};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let mut total: i32 = 0;
    let reader = BufReader::new(File::open(file_path)?);
    for line in reader.lines() {
        let num = line?
            .parse::<i32>()
            .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
        total += num;
    }
    Ok(total)
}
pub fn _sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let mut total: i32 = 0;
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    for line in reader.lines() {
        let err = io::Error::new(io::ErrorKind::InvalidData, "Invalid number");
        match line {
            Ok(num) => match num.parse::<i32>() {
                Ok(n) => total += n,
                Err(_) => return Err(err),
            },
            Err(_) => return Err(err),
        }
    }
    Ok(total)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

gtakacse

9 days ago

4.86ms

96.16kb

use std::{
    fs::File,
    io::{self, BufRead, BufReader},
};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let mut total: i32 = 0;
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    for line in reader.lines() {
        let num = line?
            .parse::<i32>()
            .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "err"))?;
        total += num;
    }
    Ok(total)
}
pub fn _sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let mut total: i32 = 0;
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    for line in reader.lines() {
        let err = io::Error::new(io::ErrorKind::InvalidData, "Invalid number");
        match line {
            Ok(num) => match num.parse::<i32>() {
                Ok(n) => total += n,
                Err(_) => return Err(err),
            },
            Err(_) => return Err(err),
        }
    }
    Ok(total)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Amit Patel

amitpatel-wstf

9 days ago

5.02ms

95.58kb

use std::fs::File;
use std::io::{self, BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum = 0;
    for line in reader.lines() {
        let line = line?;
        let no: i32 = line
            .parse()
            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
        sum += no;
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

gtakacse

9 days ago

4.68ms

96.22kb

use std::{
    fs::File,
    io::{self, BufRead, BufReader},
};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let mut total: i32 = 0;
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    for line in reader.lines() {
        let err = io::Error::new(io::ErrorKind::InvalidData, "Invalid number");
        match line {
            Ok(num) => match num.parse::<i32>() {
                Ok(n) => total += n,
                Err(_) => return Err(err),
            },
            Err(_) => return Err(err),
        }
    }
    Ok(total)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

makinpaper

9 days ago

4.81ms

95.58kb

use std::fs::File;
use std::io::{self, BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum = 0;
    for line in reader.lines() {
        let line = line?;
        let no: i32 = line
            .parse()
            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
        sum += no;
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

ychanghe

10 days ago

4.93ms

96.16kb

use std::fs::File;
use std::io::{BufReader, BufRead}; 
use std::io;
// use std::io::Error;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let filee = File::open(file_path)?; 
    let reader = BufReader::new(filee); 
    let mut sum = 0;
    for line in reader.lines(){
        let lline = line?; 
        let number = 
        match lline.parse::<i32>() {
            Err(..) => {
                return Err(io::Error::new(io::ErrorKind::InvalidData, "parsing failed")); 
            }, 
            Ok(v) => v
        }; 
        sum += number; 
    }
    return Ok(sum); 
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Snoweuph

snoweuph

10 days ago

6.27ms

96.16kb

use std::{
    fs::File,
    io::{BufRead, BufReader, Error, ErrorKind},
};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, Error> {
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut acc: i32 = 0;
    for result in reader.lines() {
        let Ok(line) = result else {
            return Err(Error::new(ErrorKind::InvalidData, "Invalid number"));
        };
        match line.parse::<i32>() {
            Err(_) => return Err(Error::new(ErrorKind::InvalidData, "Invalid number")),
            Ok(value) => {
                acc += value;
            }
        }
    }
    Ok(acc)
}

Dan Wayne

danwayne-me

11 days ago

4.70ms

96.16kb

use std::{
    fs::File,
    io::{self, BufRead, BufReader},
};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let reader = BufReader::new(File::open(file_path)?);
    let mut sum: i32 = 0;
    for line in reader.lines() {
        let line = line?;
        let line = line.trim();
        if line.is_empty() {
            continue;
        }
        let n: i32 = line.parse().map_err(|err| {
            io::Error::new(io::ErrorKind::InvalidData, format!("invalid data: {err}"))
        })?;
        sum = sum
            .checked_add(n)
            .ok_or_else(|| io::Error::new(io::ErrorKind::InvalidData, "overflow"))?;
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

<YoungAncient/>

youngancient

12 days ago

4.70ms

95.58kb

use std::fs::{File};
use std::io;
use std::io::BufRead;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = File::open(file_path)?;
    let reader = io::BufReader::new(file);
    let lines = reader.lines();
    let mut sum:i32 = 0;
    for line in lines{
        match line?.parse::<i32>(){
            Ok(value) => {
                sum += value;
            },
            Err(e) => {return Err(io::Error::new(io::ErrorKind::InvalidData, e));}
        }
        // if let Ok(value) = line?.parse::<i32>(){
        //     sum += value;
        // }else{
        //     return Err(io::Error::new(io::ErrorKind::InvalidData, e));
        // }
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Ignat S.

Igonato

13 days ago

4.80ms

96.16kb

use std::{
    fs::File,
    io::{self, BufRead, BufReader},
};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum = 0;
    for line in reader.lines() {
        sum += line?
            .parse::<i32>()
            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e.to_string()))?
    }
    return Ok(sum);
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

SpontaneousOverthrow

14 days ago

4.55ms

96.16kb

use std::fs::File;
use std::io::{self, BufReader, BufRead};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let f = File::open(file_path)?;
    let reader = BufReader::new(f);
    let lines = reader.lines();
    let mut sum = 0;
    for n in lines {
        sum = sum + n?.parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

cmdrtomalak

15 days ago

4.48ms

96.16kb

use std::{
    fs::File,
    io::{self, BufReader},
    io::prelude::*,
};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum = 0;
    for num_str in reader.lines() {
        let num_str = num_str?;
        let num = num_str.parse::<i32>()
            .map_err(|_| 
                io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
        sum += num;
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Omar Saber Talaat Abdelrahman

omar-s-ta

16 days ago

4.90ms

87.69kb

use std::io::{self, BufRead};
pub fn _sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = std::fs::File::open(file_path)?;
    let reader = io::BufReader::new(file);
    let mut sum = 0;
    for num_str in reader.lines() {
        let num = num_str?
            .parse::<i32>()
            .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
        sum += num;
    }
    Ok(sum)
}
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = std::fs::read_to_string(file_path)?;
    let mut sum = 0;
    for line in file.lines() {
        let num = line
            .parse::<i32>()
            .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
        sum += num;
    }
    Ok(sum)
}
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Omar Saber Talaat Abdelrahman

omar-s-ta

16 days ago

5.42ms

96.16kb

use std::io::{self, BufRead};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = std::fs::File::open(file_path)?;
    let reader = io::BufReader::new(file);
    let mut sum = 0;
    for num_str in reader.lines() {
        let num = num_str?
            .parse::<i32>()
            .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
        sum += num;
    }
    Ok(sum)
}
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Tim Boex

tboex

16 days ago

5.21ms

95.68kb

use std::{
    fs::File,
    io::{self, BufReader, Read},
    num::ParseIntError,
};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?;
    let mut reader = BufReader::new(file);
    let mut contents = String::new();
    reader.read_to_string(&mut contents)?;
    let mut sum = 0;
    for line in contents.lines() {
        let value: i32 = line.parse().map_err(|e: ParseIntError| {
            io::Error::new(
                io::ErrorKind::InvalidData,
                format!("Failed to parse '{}': {}", line, e),
            )
        })?;
        sum += value;
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

MöNir

Monir-Ruet

18 days ago

5.09ms

95.68kb

use std::{
    fs::File,
    io::{self, BufReader, Read},
    num::ParseIntError,
};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?;
    let mut reader = BufReader::new(file);
    let mut contents = String::new();
    reader.read_to_string(&mut contents)?;
    let mut sum = 0;
    for line in contents.lines() {
        let value: i32 = line.parse().map_err(|e: ParseIntError| {
            io::Error::new(
                io::ErrorKind::InvalidData,
                format!("Failed to parse '{}': {}", line, e),
            )
        })?;
        sum += value;
    }
    Ok(sum)
}
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Dharm Singh

dharmvr1

21 days ago

5.05ms

96.16kb


use std::{fs::File, io::{self, BufRead}};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    let mut  sum:i32 =0;
    if let Ok(file) = File::open(file_path) {
        let reader = io::BufReader::new(file);
        for line in reader.lines() {
            let line =line.map_err(|_|io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
               sum+=  line.parse::<i32>().map_err(|_|io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
         
        } Ok(sum)
    }else {
            Err(io::Error::new(io::ErrorKind::InvalidData,"invalid path"))
        }
       
    }
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

noname

random1106

22 days ago

6.06ms

96.16kb

use std::fs::File;
use std::io::{self, BufReader, BufRead};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum = 0;
    for line in reader.lines() {
        let line = line?;
        match line.parse::<i32>() {
            Ok(n) => sum += n,
            Err(_) => {
                return Err(io::Error::new(io::ErrorKind::InvalidData, format!("Invalid integer: {}", line)));
            }
        }
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

kasaxpong

22 days ago

5.39ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
  let file = File::open(file_path)?;
  let reader = BufReader::new(file);
  let mut sum = 0;
  for line in reader.lines() {
    let line = line?;
    if line.trim().is_empty() {
        continue;
    }
    match line.trim().parse::<i32>()  {
        Ok(num) => sum += num,
        Err(_) => {
            return Err(io::Error::new(
                io::ErrorKind::InvalidData,
                format!("Invalid integer in line: {}", line),
            ));
        }
    }
  }
  
  Ok(sum)  // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
}
   
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => println!("Error: {}", e),
    }
}

Gerasimos

glomvardos

23 days ago

5.49ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?; 
    let reader = BufReader::new(file);
    let mut sum = 0;
    for line in reader.lines() {
        let line = line?; 
        if line.trim().is_empty() {
            continue;
        }
        match line.trim().parse::<i32>() {
            Ok(num) => sum += num,
            Err(_) => {
                return Err(io::Error::new(
                    io::ErrorKind::InvalidData,
                    format!("Invalid integer in line: {}", line),
                ));
            }
        }
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

cremno

24 days ago

5.56ms

96.16kb

use std::fs::File;
use std::io;
use std::io::{BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let f = File::open(file_path)?;
    let reader = BufReader::new(f);
    reader.lines().map(|line| line.and_then(|valid_line| valid_line.parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number")))).sum()
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

cremno

24 days ago

4.63ms

96.16kb

use std::fs::File;
use std::io;
use std::io::{BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let f = File::open(file_path)?;
    let reader = BufReader::new(f);
    
    let mut sum = 0;
    for line in reader.lines() {
        let n = line?.parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
        sum += n;
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Mykhailo Huzhvii

Ymkavi

24 days ago

5.23ms

96.16kb

use std::io::{Error, ErrorKind, BufReader, BufRead};
use std::fs::File;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, Error> {
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum = 0;
    for line in reader.lines() {
        match line?.parse::<i32>() {
            Ok(number) => sum += number,
            _ => return Err(Error::new(ErrorKind::InvalidData, "InvalidData"))
        }
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => println!("Error: {}", e),
    }
}

yrd241

25 days ago

6.88ms

96.16kb

use std::io::{Error, ErrorKind, BufReader, BufRead};
use std::fs::File;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let f = File::open(file_path)?;
    let mut count:i32 = 0;
    for i in BufReader::new(f).lines() {
        match i?.parse::<i32>() {
            Ok(n) => count += n,
            _ => return Err(Error::new(ErrorKind::InvalidData,"InvalidData")),
        }
    }
    return Ok(count);
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Curious

Yva1n

a month ago

4.69ms

96.16kb

use std::io::{Error, ErrorKind, BufReader, BufRead};
use std::fs::File;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, Error> {
    let file = File::open(file_path)?;
    let buf = BufReader::new(file);
    let mut total: i32 = 0;
    for line in buf.lines() {
        match line?.parse::<i32>() {
            Ok(integer) => total += integer,
            _ => return Err(Error::new(ErrorKind::InvalidData, "Invalid chars")),
        }
    }
    Ok(total)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

matthew-snyder

a month ago

5.76ms

96.22kb

use std::fs::File;
use std::io;
use std::io::{BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
        let f = File::open(file_path)?;
    let buf_reader = BufReader::new(f);
    let mut result = 0;
    let invalid_number = io::Error::new(io::ErrorKind::InvalidData, "Invalid Number");
    for i in buf_reader.lines() {
        match i?.parse::<i32>() {
            //.map_err(|_| invalid_number);
            Ok(x) => result += x,
            Err(_) => return Err(invalid_number),
        }
    }
    Ok(result)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

银雀Sparrxw

Sparr0www820

a month ago

4.89ms

96.16kb

use std::fs;
use std::io::{self, BufRead};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let lines = io::BufReader::new(fs::File::open(file_path)?).lines();
    let mut sum: i32 = 0;
    for line in lines {
        match line.unwrap().parse::<i32>() {
            Ok(number) => sum += number,
            _ => return Err(io::Error::new(io::ErrorKind::InvalidData, "Invalid number")),
        }
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

银雀Sparrxw

Sparr0www820

a month ago

5.98ms

96.16kb

use std::fs;
use std::io::{self, BufRead};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = fs::File::open(file_path)?;
    let reader = io::BufReader::new(file);
    let lines = reader.lines();
    let mut sum: i32 = 0;
    for line in lines {
        match line.unwrap().parse::<i32>() {
            Ok(number) => sum += number,
            _ => return Err(io::Error::new(io::ErrorKind::InvalidData, "Invalid number")),
        }
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Kishan

wdcs-kishansudani

a month ago

6.26ms

87.42kb

use std::fs;
use std::io;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let contents = fs::read_to_string(file_path)?;
    contents
        .lines()
        .map(|line| {
            line.trim()
                .parse::<i32>()
                .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid integer"))
        })
        .sum()
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Bastien VINH

bastienvinh

a month ago

5.00ms

96.16kb

use std::io::{self, BufRead};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = std::fs::File::open(file_path)?;
    let reader = std::io::BufReader::new(file);
    let mut sum = 0;
    // Iterate over each line
    for line_result in reader.lines() {
        let line = line_result?;               // propagate I/O errors
        if line.trim().is_empty() {            // skip empty lines
            continue;
        }
        // Parse the trimmed line as i32, converting parse errors into
        // a custom io::Error so we “throw” an error on bad data
        let num: i32 = line
            .trim()
            .parse()
            .map_err(|_| std::io::Error::new(std::io::ErrorKind::InvalidData, "Invalid Number"))?;
        sum += num;
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

/sam

samging

a month ago

5.79ms

87.45kb

use std::io;
use std::fs;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = fs::read_to_string(file_path)?;
    
        let sum: i32 = file
        .split_whitespace()
        .map(|word| {
            word.parse::<i32>().map_err(|_err| {
                io::Error::new(io::ErrorKind::InvalidData, "Invalid number in file")
            })
        })
        .collect::<Result<Vec<_>, _>>()?
        .into_iter()
        .sum();
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Dr. Frederik Lauber

FrederikLauber

a month ago

5.39ms

96.16kb

use std::io;
use std::fs::File;
use std::io::BufReader;
use std::io::BufRead;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut res = 0;
    for line in reader.lines(){
        let num = line?.parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Not an integer"))?;
        res += num;
    }
    Ok(res)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Ari Karim

arikarim

a month ago

5.92ms

96.16kb


use std::{ fs::{File}, io::{self, BufRead, BufReader}};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum = 0;
    for line in reader.lines() {
        let parsed: Result<i32, _> = line?.parse().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"));
        sum += parsed?
    };
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Yummy-Yums

a month ago

5.89ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    let successful_read = File::open(file_path)?;
    let buffered_reader = BufReader::new(successful_read);
    let mut sum = 0;
    for line in buffered_reader.lines() {
        let line = line?;
        let parsed_num : i32 = line.trim().parse().map_err(|_|{
           io::Error::new(
               io::ErrorKind::InvalidData,
               format!("Could not parse number: {}", line)
           )
        })?;
        sum += parsed_num;
    }
    Ok(sum)
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

0xdangit

a month ago

7.67ms

96.16kb

use std::fs::File;
use std::io::{self, BufReader, BufRead};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    // let mut sum: i32 = 0;
    // let in_file = File::open(file_path)?;
    // let reader = BufReader::new(in_file);
    // for line in reader.lines() {
    //     match line?.parse::<i32>() {
    //         Ok(val) => sum += val,
    //         Err(_) => return Err(io::Error::new(io::ErrorKind::InvalidData, "Line doesn't contain valid number".to_string()))
    //     }
    // }
    // return Ok(sum);
    let in_file = File::open(file_path)?;
    let reader = BufReader::new(in_file);
    reader.lines()
          .map(|line| {
            line?.parse::<i32>()
                 .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Line contains invalid number"))
          })
          .sum()
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

0xdangit

a month ago

5.35ms

96.16kb

use std::fs::File;
use std::io::{self, BufReader, BufRead};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let mut sum: i32 = 0;
    let in_file = File::open(file_path)?;
    let reader = BufReader::new(in_file);
    for line in reader.lines() {
        match line?.parse::<i32>() {
            Ok(val) => sum += val,
            Err(_) => return Err(io::Error::new(io::ErrorKind::InvalidData, "Line doesn't contain valid number".to_string()))
        }
    }
    return Ok(sum);
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Asrul Firdaus

AsrulF

a month ago

5.88ms

96.16kb

use std::io::{BufReader, BufRead, Error, ErrorKind};
use std::fs::File;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = File::open(file_path)?;
    let buffer = BufReader::new(file);
    buffer
        .lines()
        .map(|line| {
            let line = line?;
            line.parse::<i32>().map_err(|_|{
                Error::new(ErrorKind::InvalidData, "Invalid number in file")
            })
        })
        .sum()
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Zisraw

a month ago

4.59ms

96.16kb

use std::io;
use std::fs::File;
use std::io::BufRead;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let mut count: i32 = 0;
    let file = File::open(file_path)?;
    let lines = io::BufReader::new(file).lines();
    
    for line in lines.map_while(Result::ok) {
        let num = line.parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
        count += num;
    }
    return Ok(count)
    // let num = lines.parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
    // lines.iter().parse()::<i32>
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

SubZ69

a month ago

7.95ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?;
    let buf = BufReader::new(file);
    let mut sum = 0;
    for (i, line) in buf.lines().enumerate() {
        let line = line?;
        let value = line.parse::<i32>().map_err(|_| {
            io::Error::new(
                io::ErrorKind::InvalidData,
                format!("Invalid integer on line {}: '{}'", i + 1, line),
            )
        })?;
        sum += value;
    }
    Ok(sum)
}
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Yashwanth

Yash981

a month ago

11.38ms

96.16kb

use std::fs::File;
use std::io;
use std::io::{BufRead,BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut total = 0;
    for line_res in reader.lines(){
        let line = line_res?;
        match line.trim().parse::<i32>(){
            Ok(num) => total += num,
            Err(_e) => return Err(io::Error::new(io::ErrorKind::InvalidData, "Invalid number")),
        }
    }
    Ok(total)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Tamir Azaouag

Tamir-Azaouag

a month ago

6.13ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum = 0;
    for line_result in reader.lines(){
        let line = line_result?;
        match line.trim().parse::<i32>(){
            Ok(num) => sum += num,
            Err(_) => {
                return  Err(io::Error::new(
                    io::ErrorKind::InvalidData, 
                    format!("Invalid number")
                ))
            }
        }
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Vincent SAMY

vsamy

a month ago

6.10ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader, Error, ErrorKind};
use std::{error, fmt};
// 1. Finish the definition
#[derive(Debug, PartialEq)]
pub enum ParsePercentageError {
    InvalidInput,
    OutOfRange,
}
// 2. Implement the `Error` trait
impl error::Error for ParsePercentageError {}
impl fmt::Display for ParsePercentageError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::InvalidInput  => write!(f, "Invalid input"),
            Self::OutOfRange => write!(f, "Percentage out of range"),
        }
    }
}
pub fn parse_percentage(input: &str) -> Result<i32, ParsePercentageError> {
    let value = input.parse::<i32>();
    match value {
        Ok(v) => Ok(v),
        _ => Err(ParsePercentageError::InvalidInput)
    }
}
// Convert to io
impl From<ParsePercentageError> for Error {
    fn from(err: ParsePercentageError) -> Error {
        match err {
            ParsePercentageError::InvalidInput => {
                Error::new(ErrorKind::InvalidData, err)
            }
            ParsePercentageError::OutOfRange => {
                Error::new(ErrorKind::InvalidData, err)
            }
        }
    }
}
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?;
    let buf = BufReader::new(file);
    let sum = buf.lines()
        .map(|line| { 
            let line = line?;
            let num = parse_percentage(&line)?;
            Ok(num)
            })
        .try_fold(0, |acc, num: Result<i32, io::Error>| Ok::<i32, io::Error>(acc + num?))?;
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}