diff --git a/exercises/13_error_handling/errors3.rs b/exercises/13_error_handling/errors3.rs index 2ef84f98..33a7b877 100644 --- a/exercises/13_error_handling/errors3.rs +++ b/exercises/13_error_handling/errors3.rs @@ -4,6 +4,17 @@ use std::num::ParseIntError; +// Don't change this function. +fn total_cost(item_quantity: &str) -> Result { + let processing_fee = 1; + let cost_per_item = 5; + let qty = item_quantity.parse::()?; + + Ok(qty * cost_per_item + processing_fee) +} + +// TODO: Fix the compiler error by changing the signature and body of the +// `main` function. fn main() { let mut tokens = 100; let pretend_user_input = "8"; @@ -14,14 +25,6 @@ fn main() { println!("You can't afford that many!"); } else { tokens -= cost; - println!("You now have {} tokens.", tokens); + println!("You now have {tokens} tokens."); } } - -fn total_cost(item_quantity: &str) -> Result { - let processing_fee = 1; - let cost_per_item = 5; - let qty = item_quantity.parse::()?; - - Ok(qty * cost_per_item + processing_fee) -} diff --git a/rustlings-macros/info.toml b/rustlings-macros/info.toml index 2a4a24ea..74cb79dd 100644 --- a/rustlings-macros/info.toml +++ b/rustlings-macros/info.toml @@ -675,8 +675,8 @@ If other functions can return a `Result`, why shouldn't `main`? It's a fairly common convention to return something like `Result<(), ErrorType>` from your `main` function. -The unit (`()`) type is there because nothing is really needed in terms of -positive results.""" +The unit type `()` is there because nothing is really needed in terms of a +positive result.""" [[exercises]] name = "errors4" diff --git a/solutions/13_error_handling/errors3.rs b/solutions/13_error_handling/errors3.rs index 4e181989..63f4aba1 100644 --- a/solutions/13_error_handling/errors3.rs +++ b/solutions/13_error_handling/errors3.rs @@ -1 +1,32 @@ -// Solutions will be available before the stable release. Thank you for testing the beta version 🥰 +// This is a program that is trying to use a completed version of the +// `total_cost` function from the previous exercise. It's not working though! +// Why not? What should we do to fix it? + +use std::num::ParseIntError; + +// Don't change this function. +fn total_cost(item_quantity: &str) -> Result { + let processing_fee = 1; + let cost_per_item = 5; + let qty = item_quantity.parse::()?; + + Ok(qty * cost_per_item + processing_fee) +} + +fn main() -> Result<(), ParseIntError> { + // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ added + let mut tokens = 100; + let pretend_user_input = "8"; + + let cost = total_cost(pretend_user_input)?; + + if cost > tokens { + println!("You can't afford that many!"); + } else { + tokens -= cost; + println!("You now have {tokens} tokens."); + } + + // Added this line to return the `Ok` variant of the expected `Result`. + Ok(()) +}