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

Rocky.C

cloki0610

21 hours ago

5.34ms

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 mut f = File::open(file_path)?;
    let reader = BufReader::new(f);
    reader.lines().map(|x| x?.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),
    }
}

Rocky.C

cloki0610

21 hours ago

4.61ms

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 mut f = File::open(file_path)?;
    let reader = BufReader::new(f);
    reader.lines().map(|x| x?.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),
    }
}

Miguel Ángel Allende

maallende

a day ago

4.79ms

95.67kb

use std::io;
use std::fs::File;
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 = File::open(file_path)?;
    let reader = BufReader::new(file);
    reader
        .lines()
        .map(|line| {
            line.map_err(|e| io::Error::new(io::ErrorKind::InvalidData, format!("Invalid line: {}", e)))
                .and_then(|s| s.trim().parse::<i32>().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, format!("Parse error: {}", e))))
        })
        .collect::<Result<Vec<i32>, io::Error>>()
        .map(|numbers| numbers.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),
    }
}

Baron Curtin

baroncurtin2

2 days ago

4.93ms

95.64kb

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 mut reader = BufReader::with_capacity(8192, file);
    let mut sum = 0i32;
    let mut line = String::with_capacity(32);
    loop {
        line.clear(); // clear but keep capacity
        match reader.read_line(&mut line)? {
            0 => break, // EOF
            _ => {
                let trimmed = line.trim();
                if !trimmed.is_empty() {
                    let num = trimmed.parse::<i32>()
                        .map_err(|_| io::Error::new(
                            io::ErrorKind::InvalidData,
                            "Invalid number"
                        ))?;
                    sum = sum.checked_add(num)
                        .ok_or_else(|| io::Error::new(
                            io::ErrorKind::InvalidData,
                            "Integer overflow"
                        ))?;
                }
            }
        }
    }
    Ok(sum)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Baron Curtin

baroncurtin2

2 days ago

4.66ms

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);
    
    reader
        .lines()
        .map(|line| {
            let line = line?;
            line.trim().parse::<i32>()
                .map_err(|_| io::Error::new(
                    io::ErrorKind::InvalidData,
                    format!("Invalid number: '{}'", line.trim())
                ))
        })
        .try_fold(0i32, |acc, num| {
            let num = num?;
            Ok(acc + num)
        })
}
// 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),
    }
}

Baron Curtin

baroncurtin2

2 days ago

23.50ms

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);
    
    reader
        .lines()
        .map(|line| {
            let line = line?;
            line.trim().parse::<i32>()
                .map_err(|_| io::Error::new(
                    io::ErrorKind::InvalidData,
                    format!("Invalid number: '{}'", line.trim())
                ))
        })
        .try_fold(0i32, |acc, num| {
            let num = num?;
            Ok(acc + num)
        })
}
// 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),
    }
}

medzernik

2 days ago

4.96ms

87.96kb

use std::io;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = std::fs::read_to_string(file_path)?;
    let mut sum = 0;
    for item in file.lines() {
        match item.parse::<i32>() {
            Ok(val) => sum += val,
            Err(_) => return Err(io::Error::from(io::ErrorKind::InvalidData)),
        }
    }
    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),
    }
}

AtlasVakyrie

4 days ago

4.42ms

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 mut f = File::open(file_path)?;
    let reader = BufReader::new(f);
    reader.lines().map(|x| x?.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),
    }
}

Tri Nguyen

nguyentri

4 days ago

5.13ms

95.55kb

use std::fs::File;
use std::io::{self, BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    let file = File::open(file_path)?; //  // Propagate file open errors
    let buf_read = BufReader::new(file);
    let mut sum = 0;
    for line in buf_read.lines() {
        let line_data = line?;
        let trimmed_line = line_data.trim();
        //if let Ok(num) = line_data.parse::<i32>() {
        //    sum += num;
        //} else {
        //    return Err(io::Error::new(
        //        io::ErrorKind::InvalidData,
        //        format!("Invalid integer: {}", trimmed_line)
        //    ));
        //};
        //let num = trimmed_line
        //    .parse::<i32>()
        //    .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, format!("Invalid integer: {}", trimmed_line)))?;
        let num = trimmed_line
            .parse::<i32>()
            .map_err(|_|io::ErrorKind::InvalidData)?;
        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),
    }
}

Tri Nguyen

nguyentri

4 days ago

4.90ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    let file = File::open(file_path)?; //  // Propagate file open errors
    let buf_read = BufReader::new(file);
    let mut sum = 0;
    for line in buf_read.lines() {
        let line_data = line?;
        let trimmed_line = line_data.trim();
        if let Ok(num) = line_data.parse::<i32>() {
            sum += num;
        } else {
            return Err(io::Error::new(
                io::ErrorKind::InvalidData,
                format!("Invalid integer: {}", trimmed_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),
    }
}

silaskoemen

5 days ago

4.39ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader, Error, ErrorKind::InvalidData};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?;
    let buf_reader = BufReader::new(file);
    let mut sum = 0;
    for line_result in buf_reader.lines() {
        let line = line_result?;
        match line.parse::<i32>() {
            Ok(num) => sum += num,
            Err(_) => return Err(Error::new(InvalidData, format!("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),
    }
}

alexsavio

6 days ago

5.00ms

96.16kb

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

coreyralph

7 days ago

5.56ms

96.16kb

use std::fs::File;
use std::io::prelude::*;
use std::io;
use std::io::BufReader;
//use std::num::ParseIntError;
//use std::io::{Error, ErrorKind};
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_i32;
    for line in reader.lines() {
        //let l = line?;
        //println!("{}",l);
        match line?.parse::<i32>() {
            Ok(num) => sum += num,
            Err(_) => return Err(io::Error::new(io::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),
    }
}

Smith Cruise

Smith-Cruise

8 days ago

5.50ms

96.16kb

use std::fs::File;
use std::io;
use std::io::{BufRead, BufReader, ErrorKind};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, 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 file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut lines = reader.lines();
    let mut total_sum = 0;
    loop {
        let line = lines.next();
        match line {
            None => {
                break;
            },
            Some(line) => {
                let val: Result<i32, _> = line?.parse();
                match val { 
                    Ok(num) => {
                        total_sum += num;
                    },
                    Err(_) => {
                        return Err(std::io::Error::new(ErrorKind::InvalidData, "error"));
                    }
                }
            }
        }
    }
    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),
    }
}

Smith Cruise

Smith-Cruise

8 days ago

5.01ms

96.16kb

use std::fs::File;
use std::io;
use std::io::{BufRead, BufReader, ErrorKind};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, 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 file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut lines = reader.lines();
    let mut total_sum = 0;
    loop {
        let line = lines.next();
        match line {
            None => {
                break;
            },
            Some(line) => {
                let val: Result<i32, _> = line?.parse();
                match val { 
                    Ok(num) => {
                        total_sum += num;
                    },
                    Err(_) => {
                        return Err(std::io::Error::new(ErrorKind::InvalidData, "error"));
                    }
                }
            }
        }
    }
    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),
    }
}

Herman effendi

hrmneffdii

8 days ago

5.07ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader, ErrorKind};
pub fn sum_integers_from_file(path: &str) -> Result<i32, io::Error> {
    let file = File::open(path)?; // Propagasi error jika file tidak bisa dibuka
    let reader = BufReader::new(file);
    let mut sum = 0;
    for line_result in reader.lines() {
        let line = line_result?; // Propagasi error saat membaca baris
        match line.trim().parse::<i32>() {
            Ok(num) => sum += num,
            Err(_) => {
                return Err(io::Error::new(
                    ErrorKind::InvalidData,
                    format!("Invalid integer: '{}'", line),
                ));
            }
        }
    }
    Ok(sum)
}

vanos001

8 days ago

8.43ms

96.16kb

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

vanos001

8 days ago

4.91ms

96.16kb

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

Ushakov Andrey

stdstring

8 days ago

5.54ms

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

Philippe Massicotte

PMassicotte

10 days ago

6.37ms

96.16kb

use std::fs::File;
use std::io;
use std::io::BufRead;
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 f = File::open(file_path)?;
    let reader = BufReader::new(f);
    let mut sum = 0;
    for line_result in reader.lines() {
        let line = line_result?;
        let number: i32 = line.trim().parse().map_err(|e| {
            io::Error::new(
                io::ErrorKind::InvalidData,
                format!("Could not parse 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),
    }
}

Kr0wZ

10 days ago

4.71ms

96.22kb

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

xxxxsk

11 days ago

4.68ms

96.16kb

use std::io;
use std::fs::File;
use std::io::BufReader;
use std::io::BufRead;
// 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 reader = BufReader::new(File::open(file_path)?);
    reader.lines().map(|line| line.unwrap().parse::<i32>().map_err(
    |_| io::Error::new(io::ErrorKind::InvalidData, "Invalid integer in file")
    )).sum()
    
}
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Enes

enesscevik

13 days ago

4.65ms

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

Luigi Terrone

LuigiTer

14 days ago

4.91ms

96.16kb

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

Satya Sundar Sahu

satya200

14 days ago

4.34ms

96.16kb

use std::fs::File;
use std::io;
use std::io::BufReader;
use std::io::BufRead;
//use std::io::Error::new;
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_line = BufReader::new(file);
    let mut sum:i32 = 0;
    for line in read_line.lines() {
        match line?.parse::<i32>() {
            Ok(n) => {sum += n;},
            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),
    }
}

Gomathi Shankar

gomathishankar37

14 days ago

5.46ms

96.21kb

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

0x0f1

Paul4673

14 days ago

5.58ms

96.16kb

use std::fs::File;
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 = File::open(file_path)?;
    let buf = io::BufReader::new(file);
    buf
    .lines()
    .map(|line| {
            line?
            .trim()
            .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),
    }
}

Heino Mortensen

hmortensen83

15 days ago

4.90ms

95.58kb

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

dattruongdev

15 days ago

4.38ms

95.55kb

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

esl

esl07

15 days ago

5.11ms

96.16kb

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 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),
    }
}

ikatlinsky

24 days ago

5.09ms

95.58kb

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 reader = BufReader::new(file);
    let mut sum = 0;
    for l in reader.lines() {
        let l = l?;
        let n = l.parse::<i32>()
            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
        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),
    }
}

diucicd

a month ago

4.30ms

96.16kb

use std::fs::File;
use std::io::{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 f = File::open(file_path)?;
    let buf = BufReader::new(f);
    let mut sum = 0;
    for line in buf.lines() {
        match line {
            Ok(line) => {
                let num = line
                    .parse::<i32>()
                    .map_err(|_| Error::new(std::io::ErrorKind::InvalidData, "Invalid integer"))?;
                sum += num;
            }
            Err(e) => return 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),
    }
}

ycgw

a month ago

4.51ms

96.16kb

use std::fs::File;
use std::io::{self, BufRead, BufReader};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?;
    let buf_reader = BufReader::new(file);
    let mut sum = 0;
    for line_result in buf_reader.lines() {
        let line = line_result?;
        match line.parse::<i32>() {
            Ok(num) => sum += num,
            Err(_) => return Err(io::Error::new(io::ErrorKind::InvalidData, format!("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),
    }
}

jeroenvgestel

a month ago

12.86ms

95.55kb

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

Sergey Matyash

matiaspub

a month ago

5.31ms

96.16kb

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

AQian

AQian0

a month ago

4.92ms

96.16kb

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

GregGorin

a month ago

4.37ms

95.58kb

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

LeonardoPinheiro23

a month ago

4.72ms

96.16kb

use std::{fs::File, io::{self, Error, BufRead, BufReader}};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    let file = File::open(file_path)?;
    let file_reader = BufReader::new(file);
    let mut sum = 0;
    for (line_index, line_result) in file_reader.lines().enumerate() {
        let line = line_result?;
        match line.trim().parse::<i32>() {
            Ok(number) => sum += number,
            Err(_) => return Err(Error::new(
                io::ErrorKind::InvalidData, 
                format!("Line {line_index}, \"{line}\", is not a valid 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),
    }
}

wry

Liudel

a month ago

5.38ms

96.16kb

use std::{
    fs::File,
    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 b = BufReader::new(f);
    let mut sum = 0;
    for l in b.lines() {
        sum += l?
            .parse::<i32>()
            .map_err(|_| std::io::Error::new(std::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),
    }
}

wry

Liudel

a month ago

5.39ms

96.16kb

use std::{
    fs::File,
    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 b = BufReader::new(f);
    let mut sum = 0;
    for l in b.lines() {
        sum += l?
            .parse::<i32>()
            .map_err(|_| std::io::Error::new(std::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),
    }
}

Kenas Zogara

kenaszogara

a month ago

4.80ms

96.16kb

use std::{fs::File, io::{self, BufRead, BufReader}};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum = 0;
    for (_, line) in reader.lines().enumerate() {
        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),
    }
}

jbrakmic

a month ago

5.98ms

96.17kb

use std::fs::File;
use std::io::BufReader;
use std::io::prelude::*;
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 file = File::open(file_path)?;
    let mut buf_reader = BufReader::new(file);
    let mut contents = String::new();
    buf_reader.read_to_string(&mut contents)?;
    Ok(contents.lines().map(|i| { 
        let val = i.parse::<i32>().map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))?;
        Ok(val)
    }).collect::<Result<Vec<_>, std::io::Error>>()?.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),
    }
}

jbrakmic

a month ago

5.99ms

96.17kb

use std::fs::File;
use std::io::BufReader;
use std::io::prelude::*;
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 file = File::open(file_path)?;
    let mut buf_reader = BufReader::new(file);
    let mut contents = String::new();
    buf_reader.read_to_string(&mut contents)?;
    let arr = contents.lines().map(|i| { 
        let val = i.parse::<i32>().map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))?;
        Ok(val)
    }).collect::<Result<Vec<_>, std::io::Error>>()?;
    Ok(arr.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),
    }
}

Tengz Mao

MaoX-Yu

a month ago

5.65ms

96.16kb

use std::io::{self, BufReader, BufRead};
use std::fs::File;
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    reader
        .lines()
        .map(|line| {
            line.and_then(|s| {
                s.trim()
                    .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),
    }
}

Tommytto

a month ago

7.09ms

95.60kb

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

Erik Hollembeak

futureperfect

a month ago

5.92ms

95.60kb

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 reader = BufReader::new(f);
    let mut total:i32 = 0;
    for line in reader.lines() {
        match line?.parse::<i32>() {
            Ok(num) => total += num,
            Err(_) => return Err(io::Error::new(io::ErrorKind::InvalidData, ""))
        }
    }
    Ok(total)
}
// Example usage
pub fn main() {
    let file_path = "numbers.txt";
    match sum_integers_from_file(file_path) {
        Ok(sum) => println!("The sum is: {}", sum),
        Err(e) => eprintln!("Error: {}", e),
    }
}

Joerg Schad

joerg84

a month ago

7.02ms

95.60kb

use std::fs::File;
use std::io::{self, BufReader, BufRead};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum:i32 = 0;
    for line in reader.lines() {
        match line?.parse::<i32>() {
            Ok(num) => sum+=num,
            Err(_) => return Err(io::Error::new(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),
    }
}

sjmellor

a month ago

7.76ms

95.55kb

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: i32 = 0;
    for line in reader.lines() {
        match line?.parse::<i32>() {
            Ok(num) => sum += num,
            _ => return 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),
    }
}

Augsorn Chanklad

up2code

a month ago

5.51ms

95.60kb

use std::fs::File;
use std::io::{self, BufReader, BufRead};
pub fn sum_integers_from_file(file_path: &str) -> Result<i32, io::Error> {
    // TODO: Implement this function
    // Hint: Use `File::open`, `BufReader::new`, and `.lines()` to process the file.
    // Use `?` to propagate errors and `io::Error::new` for custom errors.
    let file = File::open(file_path)?;
    let reader = BufReader::new(file);
    let mut sum:i32 = 0;
    for line in reader.lines() {
        match line?.parse::<i32>() {
            Ok(num) => sum+=num,
            Err(_) => return Err(io::Error::new(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),
    }
}

Zeno

djeanql

a month ago

5.80ms

95.60kb

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