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

Pranav Garg

PranavGarg01

a day ago

4.72ms

96.16kb

use std::fs::File;
use std::io::{BufRead, BufReader, Error, ErrorKind};
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 reader = BufReader::new(file);
    let mut sum = 0;
    for line in reader.lines() {
        match line?.parse::<i32>() {
            Ok(num) => sum += num,
            Err(_) => return Err(Error::new(ErrorKind::InvalidData, "Invalid")),
        }
    }
    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),
    }
}

amaneru

7ma8no9

2 days ago

6.36ms

96.16kb

use std::fs::File;
use std::io::{BufRead, BufReader, Error, ErrorKind};
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 reader = BufReader::new(file);
    let mut sum = 0;
    for line in reader.lines() {
        match line?.parse::<i32>() {
            Ok(num) => sum += num,
            Err(_) => return Err(Error::new(ErrorKind::InvalidData, "Invalid")),
        }
    }
    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),
    }
}

Sandeep chauhan

ryzen-xp

4 days ago

5.69ms

96.16kb

use std::io::{Error, ErrorKind};
use std::io::BufRead;
use std::fs::File;
use std::io::BufReader;
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.
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
      
    let mut sum  =  0 ;  
    for item  in reader.lines() {
       
       match item?.parse::<i32>() {
         Ok(num ) =>{ sum = sum + num } ,
         Err(e)=> return Err(Error::new(ErrorKind::InvalidData, "Invalid"))
       }
    }
   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),
    }
}

AKA.MoneyTaker

M4Bo2

5 days ago

6.17ms

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> {
    // Open the file
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum = 0;
    // Iterate over each line in the file
    for line in reader.lines() {
        let line = line?; // Propagate any IO error
        let num = line.trim().parse::<i32>().map_err(|e| {
            io::Error::new(io::ErrorKind::InvalidData, format!("Failed to parse '{}' as integer: {}", line, e))
        })?; // Propagate any parsing error
        sum += num; // Add the parsed integer to the sum
    }
    Ok(sum) // Return the sum of all integers
}
// 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),
    }
}

Prafful

iamsahu

6 days ago

5.47ms

96.16kb

use std::io::{Error, ErrorKind};
use std::io::BufRead;
use std::fs::File;
use std::io::BufReader;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, Error> {
    // TODO: Implement this function
    let f = File::open(file_path)?;
    let f = BufReader::new(f);
    // 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;
    for line in f.lines() {
        match line?.parse::<i32>() {
            Ok(num) => {sum = sum + num},
            Err(e) => return Err(Error::new(ErrorKind::InvalidData, "Invalid"))
        }
    }
    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),
    }
}

Dyaa Adel

dyaa-adel

7 days ago

4.88ms

96.16kb

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 = std::fs::File::open(file_path)?;
    let mut reader = io::BufReader::new(file);
    let mut sum : i32 = 0;
    for line in reader.lines() {
        let num = line.unwrap().parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
        sum = 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),
    }
}

Benjamin Falk

lumio

8 days ago

4.41ms

96.16kb

use std::io::BufRead; // Somehow this is needed?
use std::io::{self, BufReader};
use std::fs::File;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let mut sum: i32 = 0;
    let file = File::open(file_path)?;
    let buf_reader = BufReader::new(file);
    for line in buf_reader.lines() {
        let num = line?
            .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),
    }
}

Lê Minh Quân

aleister1102

8 days ago

4.98ms

96.16kb

use std::io::BufRead;
use std::io::BufReader;
use std::fs::File;
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.
    let file: File = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum: i32 = 0;
    for line in reader.lines() {
        let number = line?.parse::<i32>()
            .map_err(|_| io::Error::new(
                io::ErrorKind::InvalidData, 
                "Invalid number"))?;
        sum += 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),
    }
}

Anıl Şenay

anilsenay

9 days ago

25.73ms

95.58kb

use std::fs::File;
use std::io::BufReader;
use std::io::{self, BufRead};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let f = File::open(file_path)?;
    let reader = BufReader::new(f);
    let mut sum = 0;
    for line in reader.lines() {
        let line = line?;
        match line.parse::<i32>() {
            Ok(num) => sum += num,
            Err(e) => 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),
    }
}

TiagONTOP

9 days ago

7.55ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead}; // 🔹 Importation correcte de BufRead
use std::path::Path;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let path = Path::new(file_path);
    let file = File::open(path)?;
    let reader = io::BufReader::new(file);
    let mut sum = 0;
    for line in reader.lines() { // ✅ `.lines()` fonctionne maintenant !
        let line = line?; 
        let number: i32 = line.trim().parse()
            .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
        sum += number;
    }
    Ok(sum)
}
// Example usage
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),
    }
}

Guilherme Cesário Strachan

strachan

9 days ago

4.64ms

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 result = 0;
    for line in reader.lines() {
        let num = line?
            .parse::<i32>()
            .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
        result += num;
    }
    Ok(result)
    // 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) => eprintln!("Error: {}", e),
    }
}

Yi Hao

leongyihao

9 days ago

4.54ms

87.40kb

use std::{fs::File, io::Read};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, std::io::Error> {
	let mut handle = File::open(file_path)?;
	let mut buf = String::new();
	_ = handle.read_to_string(&mut buf);
	let numbers = buf.split_terminator("\n").map(|line| {
		line.trim().parse::<i32>()
	}).collect::<Vec<Result<i32, _>>>();
	let mut sum = 0;
	for item in numbers.iter() {
		let Ok(val) = *item else {
			return Err(std::io::Error::from(std::io::ErrorKind::InvalidData));
		};
		sum += val;
	}
	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),
    }
}

norabbito

10 days ago

4.68ms

96.16kb

use std::{
    fs::File,
    io::{self, BufRead, BufReader, 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 file = File::open(file_path)?;
    let mut sum: i32 = 0;
    for line in BufReader::new(file).lines() {
        let num = line?
            .parse::<i32>()
            .map_err(|_| 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),
    }
}

Ayushman Rathore

Spartan09

10 days ago

5.20ms

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);
    reader
        .lines()
        .map(|line| {
            line?
                .parse::<i32>()
                .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
        })
        .try_fold(0, |acc, num| num.map(|n| acc + n))
}
// 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),
    }
}

Jordan

Jordan-Haidee

13 days ago

5.74ms

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.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let fp = File::open(file_path)?;
    let reader = io::BufReader::new(fp);
    let mut res = 0;
    for l in reader.lines() {
        if let Ok(v) = l.unwrap().parse::<i32>() {
            res += v;
        } else {
            return Err(io::Error::new(io::ErrorKind::InvalidData, "error!"));
        }
    }
    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),
    }
}

tzmijewski

13 days ago

4.39ms

88.03kb

use std::fs::File;
use std::fs::read_to_string;
use std::io::{self, BufReader, ErrorKind, 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 f = File::open(file_path.to_string())?;
    //let f = BufReader::new(f);
    let f = read_to_string(file_path)?;
    let mut sum: i32 = 0;
    let error = Error::new(ErrorKind::InvalidData, "Invalid number");
    for line in f.lines() {
        let num = line.to_string().parse::<i32>();
        match num {
            
            Ok(i32) => sum+= num.unwrap(),
            Err(e) => return Err(error)
        }
    }
   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),
    }
}

Diego Maia

diegocmsantos

13 days ago

5.58ms

95.58kb

use std::io;
use std::{fs::File, io::BufRead, io::BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let f = File::open(file_path)?;
    let mut sum = 0;
    for l in BufReader::new(f).lines() {
        let l = l?;
        match l.parse::<i32>() {
            Ok(v) => {
                sum += v;
            }
            Err(why) => {
                let error = io::Error::new(io::ErrorKind::InvalidData, why);
                return Err(error);
            }
        }
    }
    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),
    }
}

Kyle Diaz

kylediaz

14 days ago

5.20ms

95.58kb

use std::fs::File;
use std::io;
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 mut sum = 0;
    for l in BufReader::new(file).lines() {
        let l = l?;
        match l.parse::<i32>() {
            Ok(v) => {
                sum += v;
            },
            Err(why) => {
                let error = io::Error::new(io::ErrorKind::InvalidData, why);
                return Err(error);
            },
        }
    }
    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),
    }
}

Donald Huber-Youmans

dHuberYoumans

15 days ago

5.05ms

96.16kb

use std::io::{BufRead,BufReader,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 reader = BufReader::new(file);
    let mut sum: i32 = 0;
    for (i,line) in reader.lines().enumerate() {
        let line = line?;
        let num = line.parse::<i32>().map_err(|_| Error::new(ErrorKind::InvalidData, format!("failed to parse line {} as i32",i)))?;
        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),
    }
}

Kenneth Love

kennethlove

16 days ago

4.98ms

96.17kb

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 mut nums: Vec<i32> = vec![];
    for line in reader.lines() {
        if let Ok(line) = line {
            if let Ok(num) = line.parse::<i32>() {
                nums.push(num)
            } else {
                return Err(io::Error::new(io::ErrorKind::InvalidData, "Bad data"))
            }
        } else {
        }
    }
    Ok(nums.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),
    }
}

Suraj Vijayan

its-me-sv

16 days 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 file_content = io::BufReader::new(file);
    file_content
        .lines()
        .map(|line| {
            line?
                .parse::<i32>()
                .map_err(|_| io::ErrorKind::InvalidData.into())
        })
        .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),
    }
}

Suraj Vijayan

its-me-sv

16 days ago

4.65ms

95.56kb

use std::io::{self, Read};
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 mut buf_reader = std::io::BufReader::new(file);
    let mut file_contents = String::new();
    let _ = buf_reader.read_to_string(&mut file_contents);
    let mut sum = 0;
    for line in file_contents.lines() {
        match line.parse::<i32>() {
            Ok(no) => sum += no,
            Err(_) => return Err(io::ErrorKind::InvalidData.into()),
        }
    }
    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),
    }
}

ludovicknecht

17 days ago

5.23ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, Error, ErrorKind};
use std::path::Path;
fn read_lines<P>(file_path: P) -> io::Result<io::Lines<io::BufReader<File>>>
where P: AsRef<Path>, {
    let file = File::open(file_path)?;
    Ok(io::BufReader::new(file).lines())
}
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, Error> {
    let lines = read_lines(&file_path)?;
    let mut sum: i32 = 0;
    for line in lines.map_while(Result::ok) {
        sum += line.parse::<i32>().map_err(|_| Error::new(ErrorKind::InvalidData, "Cannot parse value from file"))?;
    }
    Ok(sum)
}

ludovicknecht

17 days ago

4.75ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, Error, ErrorKind};
use std::path::Path;
fn read_lines<P>(file_path: P) -> io::Result<io::Lines<io::BufReader<File>>>
where P: AsRef<Path>, {
    let file = File::open(file_path)?;
    Ok(io::BufReader::new(file).lines())
}
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, Error> {
    let lines = read_lines(&file_path)?;
    let mut sum: i32 = 0;
    for line in lines.map_while(Result::ok) {
        sum += match line.parse::<i32>() {
            Ok(value) => value,
            Err(_) => return Err(Error::new(ErrorKind::InvalidData, "Cannot parse value from file")),
        };
    }
    Ok(sum)
}

Muhammad-Dennis

18 days ago

5.24ms

96.16kb

use std::fs;
use std::io;
use std::io::{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 = fs::File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum = 0;
    for line in reader.lines() {
        sum += line?
        .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),
    }
}

Jun Huang

leemars

18 days ago

4.52ms

96.16kb

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 = std::fs::File::open(file_path)?;
    let reader = std::io::BufReader::new(file);
    let mut sum = 0;
    for line in reader.lines() {
        let num = line?.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),
    }
}

manuelmj

18 days ago

5.83ms

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> {
    // 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 content = BufReader::new(file);
    let mut total_sum:i32 = 0;  
    for line in  content.lines(){
        let line = line?; 
        total_sum += line.trim().parse::<i32>() 
            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
        
        // total_sum += number;
    }
    Ok(total_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),
    }
}

alemack17

19 days ago

5.01ms

96.16kb

use std::fs::File;
use std::io;
use std::io::{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 ff=File::open(file_path)?;
    let rr=BufReader::new(ff);
    let mut sum=0;
    for l in rr.lines(){
        sum+=l?.parse::<i32>().map_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),
    }
}

Suresh Prajapati

toddlers

19 days ago

5.79ms

95.55kb

// use std::fs;
use std::io;
use std::num::ParseIntError;
use std::io::{ BufReader, BufRead };
use std::fs::File;
fn to_int(s :&str) -> Result<i32, ParseIntError> {
    s.parse()
}
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 read_contents = fs::read_to_string(file_path)?;
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut accum = 0i32;
    // for s in read_contents.split("\n"){
    //     if s!= ""{
    //     accum += to_int(&s).map_err(|_| io::ErrorKind::InvalidData)?;
    //     }
    for line in reader.lines(){
        match line?.parse::<i32>(){
            Ok(value) => accum += value,
            Err(_) => return Err(io::ErrorKind::InvalidData.into()),
        }
    }
    Ok(accum)
}
// 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),
    }
}

Suresh Prajapati

toddlers

19 days ago

4.94ms

87.96kb

use std::fs;
use std::io;
use std::num::ParseIntError;
fn to_int(s :&str) -> Result<i32, ParseIntError> {
    s.parse()
}
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 read_contents = fs::read_to_string(file_path)?;
    let mut accum = 0i32;
    for s in read_contents.split("\n"){
        if s!= ""{
        accum += to_int(&s).map_err(|_| io::ErrorKind::InvalidData)?;
        }
    }
    Ok(accum)
}
// 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),
    }
}

Whisper_icoma

1378046967

19 days ago

4.25ms

95.55kb

use std::io;
use std::io::{ BufReader, BufRead };
use std::fs::File;
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() {
        match line?.parse::<i32>() {
            Ok(value) => sum += value,
            Err(_) => return Err(io::ErrorKind::InvalidData.into()),
        }
    }
    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),
    }
}

RiyadDz22

19 days ago

7.74ms

95.55kb

use std::io;
use std::io::{ BufReader, BufRead };
use std::fs::File;
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() {
        match line?.parse::<i32>() {
            Ok(value) => sum += value,
            Err(_) => return Err(io::ErrorKind::InvalidData.into()),
        }
    }
    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),
    }
}

kosay

sarub0b0

20 days ago

5.57ms

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 lines = BufReader::new(file).lines();
    lines
        .map(|line| {
            line?
                .parse::<i32>()
                .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))
        })
        .try_fold(0, |acc, x| Ok(acc + x?))
}
// 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),
    }
}

Kentaro Abe

abekem

20 days ago

4.22ms

95.55kb

use std::io;
use std::io::{ BufReader, BufRead };
use std::fs::File;
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() {
        match line?.parse::<i32>() {
            Ok(value) => sum += value,
            Err(_) => return Err(io::ErrorKind::InvalidData.into()),
        }
    }
    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),
    }
}

automata-studio

20 days ago

4.76ms

95.58kb

use std::io::{self, BufReader, BufRead as _, ErrorKind};
use std::fs::File;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let mut sum = 0;
    let file = File::open(file_path)?;
    for line in BufReader::new(file).lines() {
        let line = line?;
        sum += line.parse::<i32>().map_err(|err| io::Error::new(ErrorKind::InvalidData, err))?;
    }
    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),
    }
}

Denis SOURON

Brack0

20 days ago

5.65ms

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 sum = 0i32;
    for line in reader.lines() {
        let number = line?
            .parse::<i32>()
            .map_err(|_| Error::new(ErrorKind::InvalidData, "invalid number"))?;
        sum += number;
    }
    Ok(sum)
}

TeDeMos

21 days ago

4.76ms

95.58kb

use std::io::{self, BufReader, BufRead as _, ErrorKind};
use std::fs::File;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?;
    let mut sum = 0;
    for line in BufReader::new(file).lines() {
        let line = line?;
        sum += line.parse::<i32>().map_err(|e| io::Error::new(ErrorKind::InvalidData, e))?;
    }
    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) => eprintln!("Error: {}", e),
    }
}

Romain Grimau

Herrgrim0

21 days ago

4.72ms

96.16kb

use std::io::prelude::*;
use std::fs::File;
use std::io;
use std::io::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 mut sum: i32 = 0;
    let file = File::open(file_path)?;
    let buf_reader = BufReader::new(file);
    for line in buf_reader.lines() {
        sum += line?.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),
    }
}

Viktor Merkurev

fennr

21 days ago

4.62ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?;
    let reader = io::BufReader::new(file);
    reader
        .lines()
        .map(|line| {
            line?
                .parse::<i32>()
                .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
        })
        .try_fold(0, |acc, x| Ok(acc + x?))
}
// 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),
    }
}

Romain Grimau

Herrgrim0

21 days ago

4.75ms

96.16kb

use std::io::prelude::*;
use std::fs::File;
use std::io;
use std::io::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 mut sum: i32 = 0;
    let file = File::open(file_path)?;
    let buf_reader = BufReader::new(file);
    for line in buf_reader.lines() {
        sum += line?.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),
    }
}

iamforgettable

21 days ago

6.20ms

95.55kb

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 fh = File::open(file_path)?;
    let br = BufReader::new(fh);
    let mut sum = 0;
    for line_result in br.lines() {
        sum +=  line_result?.parse::<i32>().map_err(|_|  (io::ErrorKind::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) => eprintln!("Error: {}", e),
    }
}

Nikita Smirnov

Nismirno

22 days ago

5.07ms

95.55kb

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 lines = reader.lines();
    let mut sum: i32 = 0;
    for line in lines {
        let line = line?;
        sum += line
            .parse::<i32>()
            .map_err(|_| io::Error::from(io::ErrorKind::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) => eprintln!("Error: {}", e),
    }
}

Nikita Smirnov

Nismirno

22 days ago

5.81ms

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 lines = reader.lines();
    let mut sum: i32 = 0;
    for line in lines {
        let line = line?;
        sum += line
            .parse::<i32>()
            .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "invalid 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),
    }
}

Algorab

22 days ago

5.33ms

95.55kb

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> {
    let file =  File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum: i32 = 0;
    for line in reader.lines() {
        let line = line?;
        let num = line.parse::<i32>().map_err(|_e| io::Error::from(io::ErrorKind::InvalidData))?;
        sum = sum + num;
    }
    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.
}

Elliott Draper

ejdraper

23 days ago

5.30ms

96.16kb

use std::fs::File;
use std::io::{BufRead, BufReader, Error, ErrorKind};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, Error> {
    let f = File::open(file_path)?;
    let buf = BufReader::new(f);
    let lines = buf.lines().map(|line| line.unwrap());
    let mut sum = 0;
    for line in lines {
        let num: Result<i32, _> = str::parse(&line);
        match num {
            Ok(parsed_num) => {
                sum = sum + parsed_num;
            }
            Err(_) => {
                return Err(Error::new(ErrorKind::InvalidData, "Unable to parse num."))
            }
        }
    }
    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),
    }
}

Simon Noetzlin

sainoe

23 days ago

4.41ms

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 mut sum : i32 = 0;
  // Step 1: Open the file
    let file = File::open(file_path)?;
    // Step 2: Create a BufReader
    let reader = BufReader::new(file);
   
    // Step 3: Iterate over the lines
    for line in reader.lines() {
        let num = line?.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),
    }
}

rawar089

24 days ago

4.75ms

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 r = BufReader::new(File::open(file_path)?);
    let mut sum: i32 = 0;
    for n in r.lines() {
        let num = n.unwrap().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),
    }
}

Marco-Normal

24 days ago

6.38ms

96.16kb

use std::fs;
use std::io::{self, BufReader};
use std::io::prelude::*;
use std::io::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 = fs::File::open(file_path)?;
    let contents = BufReader::new(file);
    let mut ans: i32 = 0;
    for line in contents.lines() {
        let number = match line?.parse::<i32>() {
            Ok(n) => n,
            Err(e) => return Err(io::Error::new(ErrorKind::InvalidData, "Invalid number"))
        };
        ans += number;
    }
    Ok(ans)
}
// 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),
    }
}

Stefan Roas

sroas

24 days ago

5.25ms

95.57kb

use std::{
    fs::File,
    io::{self, BufRead, BufReader, ErrorKind},
    num::ParseIntError,
};
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);
    match reader
        .lines()
        .map_while(core::result::Result::ok)
        .map(|line| line.parse::<i32>())
        .collect::<Result<Vec<_>, ParseIntError>>()
    {
        Ok(v) => Ok(v.into_iter().sum()),
        Err(_) => Err(std::io::Error::new(ErrorKind::InvalidData, "invalid data")),
    }
}
// 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),
    }
}

Jim Lawton

jimlawton

24 days ago

5.76ms

96.16kb

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 f = File::open(file_path)?;
    let reader = io::BufReader::new(f);
    let lines = reader.lines().map(|l| l.unwrap());
    let mut sum: i32 = 0;
    for line in lines {
        if let Ok(val) = line.parse::<i32>() {
            sum += val;
        } else {
            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),
    }
}