error_tools 0.39.0

Basic exceptions handling mechanism
Documentation 
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//! A runnable example demonstrating the `ErrWith` trait.

use error_tools ::error :: { ErrWith };
use std ::io;

fn might_fail_io(fail: bool) -> io ::Result< u32 > 
{
  if fail 
  {
  Err(io ::Error ::other("simulated I/O error"))
 } else {
  core ::result ::Result ::Ok(42)
 }
}

fn process_data(input: &str) -> core ::result ::Result< String, (String, Box<dyn core ::error ::Error >)> 
{
  let num = input.parse :: < u32 >().err_with(|| "Failed to parse input".to_string())?;

  let result = might_fail_io(num % 2 != 0).err_with_report(&format!("Processing number {num}"))?;

  core ::result ::Result ::Ok(format!("Processed result: {result}"))
}

fn main() 
{
  println!("--- Successful case ---");
  match process_data("100") 
  {
  core ::result ::Result ::Ok(msg) => println!("Success: {msg}"),
  core ::result ::Result ::Err((report, err)) => println!("Error: {report} - {err:?}"),
 }

  println!("\n--- Parsing error case ---");
  match process_data("abc") 
  {
  core ::result ::Result ::Ok(msg) => println!("Success: {msg}"),
  core ::result ::Result ::Err((report, err)) => println!("Error: {report} - {err:?}"),
 }

  println!("\n--- I/O error case ---");
  match process_data("1") 
  {
  core ::result ::Result ::Ok(msg) => println!("Success: {msg}"),
  core ::result ::Result ::Err((report, err)) => println!("Error: {report} - {err:?}"),
 }
}