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

Christophe Mohimont

mohic

2 days ago

4.28ms

95.55kb

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

firefly

KamisAyaka

5 days ago

4.69ms

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?;
        let trimmed = line.trim();
        
        if trimmed.is_empty() {
            continue;
        }
        
        let num: i32 = trimmed.parse().map_err(|e| {
            io::Error::new(
                io::ErrorKind::InvalidData,
                format!("Failed to parse '{}' as integer: {}", trimmed, e),
            )
        })?;
        
        sum += num;
    }
    Ok(sum)
}
// Example usage remains the same
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),
    }
}

amdfxlucas

6 days ago

8.63ms

95.58kb

use std::io::BufRead;
use std::io;
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 file = File::open(file_path)?;
    let buf_reader = std::io::BufReader::new(file);
    //buf_reader.lines().map( |xx| {xx.map( |x|{x.as_str().parse::<i32>().map_err(Err(io::ErrorKind::InvalidData) ) } ) } ).sum()
    let mut sum: i32 = 0;
    for line in buf_reader.lines()
    {
        match line{
            Ok(l) =>{ match l.parse::<i32>()
                    {
                        Ok(i) => {sum += i;},
                        Err(e) => {return Err(io::Error::new(io::ErrorKind::InvalidData, e)) }
                    }
                    },
            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),
    }
}

muemart

6 days ago

5.36ms

96.16kb

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

Bryan

yuyangchen23

7 days ago

4.74ms

96.16kb

use std::fs;
use std::io::{self, 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 = fs::File::open(file_path)?;
    let mut reader = BufReader::new(file);
    let mut sum = 0;
    for l in reader.lines() {
        let line = l?;
        let mut num = match line.trim().parse::<i32>() {
            Ok(n) => n,
            Err(_) => return Err(io::Error::new(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),
    }
}

ashishkr2912

8 days ago

5.94ms

96.16kb

use std::{fmt, io};
use std::fs::File;
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 f = BufReader::new(file)
        .lines()
        .map(|line| line.and_then(|s| s.parse::<i32>()
            .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Failed to parse integer"))))
        .sum::<Result<i32, io::Error>>()?;
    Ok(f)
}
// 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),
    }
}

johnson

ssebide

12 days ago

5.72ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader, Error, 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() {
        sum += line?
            .as_str()
            .parse::<i32>()
            .map_err(|_| io::Error::new(ErrorKind::InvalidData, "error parsing int"))?;
    }
    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),
    }
}

undefeated_

boyboi86

12 days ago

4.31ms

96.16kb

use std::fs::File;
use std::io::{self, BufReader, BufRead}; // need BufRead to iter
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 open_file = File::open(file_path)?;
    let read_file = BufReader::new(open_file);
    //let mut total_sum: i32 = 0;
    // slightly slower due to unwrap and require additional import std::io::BufRead
    //for line_result in read_file.lines() {
        //let error = io::Error::new(io::ErrorKind::InvalidData, "Invalid number");
        //total_sum += line_result.unwrap().parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
    //}
    read_file
    .lines()
    .map(|line| {
        line?.parse::<i32>() //propogate error here during mapping
        .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))
        }).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),
    }
}

Thomas Michiels

mithom

12 days ago

5.52ms

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 buff = io::BufReader::new(file);
    buff.lines()
        .map(|x| 
            x?.parse::<i32>()
              .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
        ).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),
    }
}

StevenCanDrink

13 days ago

4.39ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader};
use std::path::Path;
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 num: i32 = line.trim().parse().map_err(|e| {
            io::Error::new(
                io::ErrorKind::InvalidData,
                format!("Invalid integer in file: {}", e)
            )
        })?;
        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),
    }
}

GunGraveCpp

15 days ago

5.03ms

96.16kb

use std::{fs::File, 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);
    reader
        .lines()
        .map(|l| {
            l?.parse::<i32>()
                .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
        })
        .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),
    }
}

David Rasch

dcrasch

15 days ago

4.72ms

96.16kb

use std::io::{self,BufRead,BufReader};
use std::fs::File;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?; // Open the file, propagate error if any
    let reader = BufReader::new(file); // Wrap it in a buffered reader
    reader
        .lines()
        .map(|l| l?
            .parse::<i32>()
            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e)))
        .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),
    }
}

Lvfalue

16 days ago

5.03ms

95.58kb

use std::io;
use std::io::BufRead;
use std::io::BufReader;
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 file = File::open(file_path)?;
    let buf = BufReader::new(&file);
    let mut sum = 0;
    for line in buf.lines() {
        let line = line?;
        let num = line.trim().parse::<i32>().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
        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),
    }
}

Artem Nistuley

artemnistuley

18 days ago

4.62ms

96.16kb

use std::io;
use std::fs::File;
use std::io::{Error, 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: i32 = 0;
    for line in reader.lines() {
        let num = line?.parse::<i32>().map_err(|_e| Error::new(io::ErrorKind::InvalidData, "Invalid data"))?;
        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),
    }
}

Jean-baptiste JOFFRE

Indy79

19 days ago

4.80ms

96.17kb

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 mut file = File::open(file_path)?;
    let mut data: Vec<i32> = vec![];
    let lines = BufReader::new(&mut file).lines();
    for line in lines {
        match line { 
            Ok(l) => {
                match l.parse() {
                    Ok(num) => data.push(num),
                    Err(_) => return Err(io::Error::new(io::ErrorKind::InvalidData, "Invalid number")),
                }
            },
            Err(e) => return Err(e),
        }
    }
    Ok(data.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),
    }
}

YVV

yvv4git

20 days ago

4.83ms

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_number, line) in reader.lines().enumerate() {
        let line = line?;
        match line.trim().parse::<i32>() {
            Ok(num) => sum += num,
            Err(_) => {
                return Err(io::Error::new(
                    io::ErrorKind::InvalidData,
                    format!("Invalid integer at line {}", line_number + 1)
                ));
            }
        }
    }
    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),
    }
}

visanr

21 days ago

4.82ms

96.16kb

use std::io;
use std::fs::File;
use std::io::{Error, BufReader, 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: i32 = 0;
    for line in reader.lines() {
        let num = line?.parse::<i32>().map_err(|_e| Error::new(io::ErrorKind::InvalidData, "Invalid data"))?;
        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.
}
// 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),
    }
}

toto

21 days ago

4.75ms

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 lines = BufReader::new(file).lines();
    lines
        .map(|line| {
            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),
    }
}

Lucas Watkins

lucas-watkins

22 days ago

5.35ms

96.16kb

use std::fs::File;
use std::io::{BufReader, BufRead, 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() {
        let res = line?.parse::<i32>();
        if let Ok(n) = res {
            sum += n;
        } else {
            return Err(Error::new(ErrorKind::InvalidData, "Invalid Integer"));
        }
    }
    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),
    }
}

Luka Bračun

lbracun

23 days ago

4.85ms

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();
    lines
        .map(|line| {
            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),
    }
}

bzdula

23 days ago

6.06ms

95.62kb

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 sum: i32 = reader
        .lines()
        .map(|line| {
            let line = line?;
            line.parse::<i32>()
                .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Oh noes"))
        })
        .collect::<Result<Vec<_>, _>>()?
        .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),
    }
}

Ranjith Thangavel

RanjithECE24

24 days ago

5.47ms

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)?; // Propagate error if file doesn't open
    let reader = BufReader::new(file);
    let mut sum = 0;
    for line in reader.lines() {
        let line = line?; // Propagate I/O errors while reading lines
        let number: i32 = line.trim().parse().map_err(|e| {
            io::Error::new(io::ErrorKind::InvalidData, format!("Invalid number: {}", e))
        })?;
        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),
    }
}

Dimas Avrian Fachriza.

FForFachriza

25 days ago

4.67ms

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
    let files = File::open(file_path)?;
    let reader = BufReader::new(files);
    let mut sum: i32 = 0;
    for line in reader.lines() {
        match line?.trim().parse::<i32>() {
            Ok(line) => {
                sum += line;
            }
            Err(_) => return Err(io::Error::new(io::ErrorKind::InvalidData, "Invalid 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),
    }
}

Christopher Deutsch

chrisdeutsch

a month ago

4.60ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader, Error, 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() {
        sum += line?
            .as_str()
            .parse::<i32>()
            .map_err(|_| io::Error::new(ErrorKind::InvalidData, "error parsing int"))?;
    }
    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),
    }
}

Tommy

verse215

a month ago

5.35ms

96.16kb

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

Wouter

WouterMartens

a month ago

4.49ms

87.48kb

use std::fs;
use std::io::{self, Error, ErrorKind};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    fs::read_to_string(file_path)?
        .lines()
        .enumerate()
        .try_fold(0, |acc, (i, line)| {
            line.parse::<i32>()
                .map(|val| acc + val)
                .map_err(|e| {
                    Error::new(
                        ErrorKind::InvalidData,
                        format!("Invalid value \"{}\" on line {} with error {}", line, i, e)
                    )
                })
        })
}
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),
    }
}

yba01

a month ago

5.69ms

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 buf = io::BufReader::new(f);
    let mut sum: i32 = 0;
    for line in buf.lines() {
        let line = line?;
        let val = line.parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid Line"))?;
        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),
    }
}

shahab-tplus

a month ago

5.84ms

96.16kb

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

shahab-tplus

a month ago

8.83ms

96.17kb

use std::fs::File;
use std::io::{BufRead,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 f = File::open(file_path)?;
    let reader = BufReader::new(f);
    let mut numbers = Vec::new();
    for line in reader.lines() {
        let line = line?;
        match line.parse::<i32>() {
            Ok(n) => numbers.push(n),
            Err(_) => return Err(io::Error::new(io::ErrorKind::InvalidData, "Invalid")),
        }
    }
    let sum = numbers.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),
    }
}

whhc

a month ago

4.64ms

95.67kb

use std::{
    fs::File,
    io::{self, BufRead, BufReader, Error},
};
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 error = io::Error::new(io::ErrorKind::InvalidData, "Invalid number");
    let file = File::open(file_path)?;
    let lines = BufReader::new(file);
    let mut count = 0;
    for line in lines.lines() {
        match line {
            Ok(num_str) => {
                let num = num_str
                    .parse::<i32>()
                    .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
                count += num;
            }
            Err(_) => return Err(error),
        }
    }
    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),
    }
}

noomcreator

a month ago

4.49ms

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 = 0;
    for line_result in reader.lines() {
        let num_str = line_result?;
        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),
    }
}

Jai

jsat97

a month ago

4.39ms

95.63kb

use std::fs::File;
//use std::io::prelude::*;
use std::io::{self,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 f = File::open(file_path)?;
    let reader = BufReader::new(f);
    let vec :  Result<Vec<i32>, io::Error> = 
    reader.lines()
    .map(|line| {
        line.and_then(|line_str| {
        line_str.trim().parse::<i32>()
        .map_err(|_| io::Error::new(ErrorKind::InvalidData, "Invalid number")) 
        })
    })
    .collect();
    let vec = vec?; 
    Ok(vec.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),
    }
}

Andy Randrianirina

andyslash

a month ago

4.94ms

96.16kb

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

Chih Ying Yen

xavierforge

a month ago

5.12ms

96.16kb

use std::io;
use std::io::prelude::*;
use std::io::BufReader;
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 reader = BufReader::new(f);
    let mut sum = 0;
    for line in reader.lines() {
        sum += line?.parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid numbr"))?;
    }
    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),
    }
}

Daniel Mestas

miel-codeai

a month ago

4.57ms

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);
    reader
        .lines()
        .map(|line| {
            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),
    }
}

aghia98

a month ago

4.78ms

96.16kb

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

orao-pao

a month ago

4.78ms

96.16kb

use std::fs::File;
use std::io;
use std::io::{BufReader,BufRead,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 my_file = File::open(file_path)?;
    let mut read_file = BufReader::new(my_file);
    let mut sum = 0;
    for read_line in read_file.lines(){
        if let Ok(extracted_text) = read_line {
            //let error = Error::new(ErrorKind::InvalidData, "Invalid number");
            sum += extracted_text
                .parse::<i32>()
                .map_err(|_| Error::new(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),
    }
}

baschdik

a month ago

4.92ms

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 myfile = File::open(file_path)?;
    let reader = BufReader::new(myfile);
    let mut sum = 0;
    for lines in reader.lines() {
        
        sum += lines?.parse::<i32>().map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid number"))?;
        //match lines?.parse::<i32>() {
        //    Ok(val) => sum += val,
        //    Err(_) => 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),
    }
}

baschdik

a month ago

5.92ms

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 myfile = File::open(file_path)?;
    let reader = BufReader::new(myfile);
    let mut sum = 0;
    for lines in reader.lines() {
        
        //sum += lines?.parse::<i32>().unwrap();
        match lines?.parse::<i32>() {
            Ok(val) => sum += val,
            Err(_) => 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),
    }
}

Evgenii Uglanov

winchest3r

a month ago

4.80ms

96.16kb

use std::io;
use std::fs;
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 = fs::File::open(file_path)?;
    let mut file_buf = io::BufReader::new(file);
    let mut result = 0;
    for line in file_buf.lines() {
        let line = line?;
        let Ok(val) = str::parse::<i32>(&line) else {
            return Err(io::Error::new(io::ErrorKind::InvalidData, "cannot parse a line"));
        };
        result += val;
    }
    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),
    }
}

Gurneet singh

GS-Jatt

a month ago

5.05ms

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 = 0;
    for line in lines {
        if let Ok(c) = line {
            if let Ok(x) = c.parse::<i32>() {
                sum += x;
            } else {
                return Err(io::Error::new(io::ErrorKind::InvalidData, "invialid data"));
            }
        }
    }
    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),
    }
}

manu3618

a month ago

5.78ms

89.47kb

use std::io;
use std::fs::File;
use std::io::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 mut content = String::new();
    let mut f = File::open(file_path)?;
    let _ = dbg!(f.read_to_string(&mut content))?;
    dbg!(&content);
    let res: Result<Vec<i32>, _> = content.lines().map(|s| String::from(s).parse::<i32>()).collect();
    match dbg!(res) {
        Ok(v) => Ok(v.iter().sum()),
        _ => Err(io::Error::new(io::ErrorKind::InvalidData, "unable to parse line")),
    }
}
// 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 Coccato

Ocrambana

a month ago

4.94ms

95.58kb

use std::io;
use std::io::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.
    let file = File::open(file_path)?;
    let reader = io::BufReader::new(file);
    let mut sum : i32 = 0;
    for l in reader.lines()
    {
        let li = l.unwrap();
        
        match li.parse::<i32>()
        {
            Ok(v) => sum += v,
            Err(e) => return Err(io::Error::new(io::ErrorKind::InvalidData,e)),
        }
    }
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    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),
    }
}

Fatih

0fatih

a month ago

4.46ms

96.16kb

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

slaws

a month ago

5.00ms

96.22kb

use std::{io,{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 fd = File::open(file_path)?;
    let buff = io::BufReader::new(fd);
    let mut sum = 0;
    for l in buff.lines() {
        let li = l.unwrap();
        println!("{:?}", li);
        if let Ok(val) = li.parse::<i32>() {
            sum += val;
        } else {
            return Err(io::Error::new(io::ErrorKind::InvalidData, "foobar"));
        }
    }
    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),
    }
}

Christopher Kolbe

chkolbe

a month ago

4.36ms

96.16kb

use std::io::{BufReader, BufRead};
use std::fs::File;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, std::io::Error> {
    let file = File::open(file_path)?;
    let buffer = BufReader::new(file);
    let lines = buffer.lines();
    lines.map(|line|
        line?
            .parse::<i32>()
            .map_err(|_| std::io::Error::new(std::io::ErrorKind::InvalidData, "parse error"))
    )
    .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),
    }
}

Christopher Kolbe

chkolbe

a month ago

4.47ms

96.16kb

use std::io::{BufReader, BufRead};
use std::fs::File;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, std::io::Error> {
    let file = File::open(file_path)?;
    let buffer = BufReader::new(file);
    let lines = buffer.lines();
    lines.map(|line|
        line?
            .parse::<i32>()
            .map_err(|_| std::io::Error::new(std::io::ErrorKind::InvalidData, "parse error"))
    )
    .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),
    }
}

Evrins Hu

evrins

a month ago

4.89ms

96.16kb

use std::fs::File;
use std::io::{BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, std::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();
    lines
        .map(|line|
            line?
                .parse::<i32>()
                .map_err(|_| std::io::Error::new(std::io::ErrorKind::InvalidData, "parse error"))
        )
        .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),
    }
}

Mark

schmark88

a month ago

5.13ms

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 reader = BufReader::new(File::open(file_path)?);
    reader
        .lines()
        .map_while(Result::ok)
        .map(|l|{
            l.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),
    }
}

johndoe30bc

a month ago

6.17ms

96.16kb

use std::{
    fs::File,
    io::{self, BufRead, BufReader},
};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let f = File::open(file_path)?;
    let input = BufReader::new(f);
    let mut sum = 0;
    for (idx, line) in input.lines().enumerate() {
        let n = line?.parse::<i32>().map_err(|e| {
            io::Error::new(
                io::ErrorKind::InvalidData,
                format!("at line {}: {e}", idx + 1),
            )
        })?;
        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),
    }
}