Crate not_found_error

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Expand description

§Overview

// Convert Option<i32> to Result<i32, NotFoundError<i32>>

assert_eq!(Some(10).require(), Ok(10));

assert_eq!(None.require(), Err(NotFoundError::<i32>::new()));

This crate provides a generic NotFoundError<T> type and associated utilities for handling “not found” scenarios in a type-safe and ergonomic manner.

You can convert Option<T> to Result<T, NotFoundError<T> using require function or Require extension trait.

You can convert Option<T> to Result<T, NotFoundError<AnotherType> using not_found function or OkOrNotFound extension trait.

§Features

  • Generic NotFoundError<T> type
  • Conversion functions and traits to transform Option<T> into Result<T, NotFoundError<T>>
  • Conversion functions and traits to transform Option<T> into Result<T, NotFoundError<AnotherType>>

§Examples

use not_found_error::{NotFoundError, Require, locate, require};

// Using the `require` function
let item = require([1, 2, 3].into_iter().next());
assert_eq!(item, Ok(1));

// Using the `require` function
let item = require([].into_iter().next());
assert_eq!(item, Err(NotFoundError::<i32>::new()));

// Using the `require` extension method
let item = [1, 2, 3].into_iter().next().require();
assert_eq!(item, Ok(1));

// Using the `require` extension method
let item = [].into_iter().next().require();
assert_eq!(item, Err(NotFoundError::<i32>::new()));

// Try to find a number greater than 10 (which doesn't exist in our list)
let numbers = &[1, 2, 3];
let result = locate(numbers, |&&n| n == 0);
assert_eq!(result, Err(NotFoundError::new()));

Structs§

NotFoundError
Represents an error indicating that a value was not found.

Traits§

OkOrNotFound
An extension trait for Option<T> to convert it to Result<T, NotFoundError<AnotherType>>
Require
An extension trait for Option<T> to convert it to Result<T, NotFoundError<T>>

Functions§

locate
Searches an iterator for an element that satisfies a given predicate and returns a reference to it.
not_found
A shorter version of NotFoundError::new().
require
Converts Option<T> to Result<T, NotFoundError<T>>

Type Aliases§

Result
A type alias for Result<T, NotFoundError<T>>