diff --git a/src/doc/trpl/error-handling.md b/src/doc/trpl/error-handling.md index 673dc950ecce4..0687c2b13b5b5 100644 --- a/src/doc/trpl/error-handling.md +++ b/src/doc/trpl/error-handling.md @@ -33,12 +33,12 @@ systems may want to jump around. * [Composing `Option` and `Result`](#composing-option-and-result) * [The limits of combinators](#the-limits-of-combinators) * [Early returns](#early-returns) - * [The `try!` macro](#the-try-macro) + * [The `try!` macro](#the-try!-macro) * [Defining your own error type](#defining-your-own-error-type) * [Standard library traits used for error handling](#standard-library-traits-used-for-error-handling) * [The `Error` trait](#the-error-trait) * [The `From` trait](#the-from-trait) - * [The real `try!` macro](#the-real-try-macro) + * [The real `try!` macro](#the-real-try!-macro) * [Composing custom error types](#composing-custom-error-types) * [Advice for library writers](#advice-for-library-writers) * [Case study: A program to read population data](#case-study-a-program-to-read-population-data) @@ -87,7 +87,9 @@ thread '
' panicked at 'Invalid number: 11', src/bin/panic-simple.rs:5 Here's another example that is slightly less contrived. A program that accepts an integer as an argument, doubles it and prints it. + ```rust,should_panic + use std::env; fn main() { @@ -120,10 +122,9 @@ It would be better if we just showed the code for unwrapping because it is so simple, but to do that, we will first need to explore the `Option` and `Result` types. Both of these types have a method called `unwrap` defined on them. -## The `Option` type +### The `Option` type -The `Option` type is -[defined in the standard library][1]: +The `Option` type is [defined in the standard library][5]: ```rust enum Option { @@ -138,6 +139,7 @@ system is an important concept because it will cause the compiler to force the programmer to handle that absence. Let's take a look at an example that tries to find a character in a string: + ```rust // Searches `haystack` for the Unicode character `needle`. If one is found, the // byte offset of the character is returned. Otherwise, `None` is returned.