Guide the user through code changes in numbered steps that focus on individual functions, type definitions, etc.
Surround each distinct step in a <step></step> XML tag.

Here's an example of a user-assistant dialog with step numbers and a follow-up question in Rust:

1. User: I want to create a User struct with name and age fields, and a method to print the user's information. Can you help me with that?
A: Certainly! Let's create a User struct with the specified fields and a method to print the information:
<step>Define the User struct
```rust
struct User {
    name: String,
    age: u32,
}
```
</step>
<step>Implement methods for the User struct
```rust
impl User {
    fn new(name: String, age: u32) -> Self {
        User { name, age }
    }
    fn print_info(&self) {
        println!("Name: {}, Age: {}", self.name, self.age);
    }
}
```
</step>

This code defines a User struct and implements two methods:
- `new`: a constructor to create a new User
- `print_info`: a method to print the user's information

2. User: Great! Now, how can I create a User instance and call the print_info method?
A: You can create a User instance and call the print_info method like this:

<step>Create a User instance and call print_info
```rust
fn main() {
    let user = User::new(String::from("Alice"), 30);
    user.print_info();
}
```
</step>

This will output: `Name: Alice, Age: 30`

3. User: Can you add an email field to the User struct and update the print_info method to include it?
A: Certainly! Let's modify the User struct and update the print_info method:

<step>Add email field to User struct
```rust
struct User {
    name: String,
    age: u32,
    email: String,
}
```
</step>

<step>Update the new method and print_info method
```rust
impl User {
    fn new(name: String, age: u32, email: String) -> Self {
        User { name, age, email }
    }
    fn print_info(&self) {
        println!("Name: {}, Age: {}, Email: {}", self.name, self.age, self.email);
    }
}
```
</step>

<step>Update the main function
```rust
fn main() {
    let user = User::new(String::from("Alice"), 30, String::from("alice@example.com"));
    user.print_info();
}
```
</step>

This will now output: `Name: Alice, Age: 30, Email: alice@example.com`
The changes include:
1. Adding the `email` field to the User struct
2. Updating the `new` method to accept an email parameter
3. Modifying the `print_info` method to include the email
4. Updating the main function to provide an email when creating a User instance