CodeBlanks Logo Icon CodeBlanks
Login Register

Task model

Define the Todo struct and its fields.

Todo list: the model

In this project we'll write a small todo list that runs from the command line: adding tasks, listing, marking as done and reading commands. The first step is modelling the data. Every task has an id, a text and a done state:

struct Gorev {
    id: u32,
    metin: String,
    bitti: bool,
}

We chose String for metin because the task should own its text; if we held a &str, the text would have to live somewhere else.

Showing a task

Let a method decide how the task looks on screen. Finished tasks will be shown with [x], the others with [ ]:

impl Gorev {
    fn goster(&self) -> String {
        let isaret = if self.bitti { "x" } else { " " };
        format!("[{}] {}: {}", isaret, self.id, self.metin)
    }
}

Since the method returns a String, printing, testing or saving the result to a file can all use the same code.

Practice First task

Add the method fn goster(&self) -> String to the Gorev struct. Create the task with id: 1, metin: "Süt al" and bitti: false, and print the result of goster().

Starter code

main.rs
struct Gorev {
    id: u32,
    metin: String,
    bitti: bool,
}

fn main() {
    // buraya yaz
}

Sample solution

main.rs
struct Gorev {
    id: u32,
    metin: String,
    bitti: bool,
}

impl Gorev {
    fn goster(&self) -> String {
        let isaret = if self.bitti { "x" } else { " " };
        format!("[{}] {}: {}", isaret, self.id, self.metin)
    }
}

fn main() {
    let g = Gorev {
        id: 1,
        metin: String::from("Süt al"),
        bitti: false,
    };
    println!("{}", g.goster());
}

Expected output

[ ] 1: Süt al

Questions and answers

Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.

1 Which type best fits a task's done state?

  • u8
  • Option<String>
  • bool Correct answer
  • String

Explanation: For two-state information (done/not done), bool is both clear and safe.

2 Pick the mark

Question 
let isaret = ____ self.bitti { "x" } else { " " };
Answer 
let isaret = if self.bitti { "x" } else { " " };

Explanation: In Rust if is an expression; it can produce a value and be assigned to a variable.

3 Field and type

Term Meaning
id u32
metin String
bitti bool
goster() -> String

All lessons in Beginner

1 Rust basics

  1. What is Rust?
  2. Project with Cargo
  3. Your first program
  4. println! and formatting
  5. Comments
  6. Summary - Rust basics

2 Variables

  1. Variables with let
  2. Mutability with mut
  3. Constants with const
  4. Static variables
  5. Shadowing
  6. Summary - Variables

3 Data types

  1. Integers
  2. Floating point
  3. Bool and char
  4. Tuple
  5. Array
  6. Summary - Data types

4 Strings

  1. &str vs String
  2. Creating a String
  3. Concatenating strings
  4. format! macro
  5. String length
  6. Summary - Strings

5 Project: Calculator

  1. Project skeleton
  2. Reading input
  3. Computing
  4. Error handling
  5. Loop and exit

6 Functions

  1. Defining with fn
  2. Parameters
  3. Return value
  4. Expressions and statements
  5. Early return
  6. Summary - Functions

7 Control flow

  1. if-else
  2. match basics
  3. loop
  4. while loop
  5. for loop
  6. Summary - Control flow

8 Ownership

  1. What is ownership?
  2. Move semantics
  3. Copy trait
  4. Functions and ownership
  5. Return and ownership
  6. Summary - Ownership

9 Borrowing

  1. References
  2. Mutable reference
  3. Borrowing rules
  4. Dangling reference
  5. References and functions
  6. Summary - Borrowing

10 Slices

  1. String slices
  2. Slice syntax
  3. Array slices
  4. Slices and functions
  5. Range types
  6. Summary - Slices

11 Project: Guessing game

  1. Game skeleton
  2. Reading input
  3. Comparing numbers
  4. Random number
  5. Loop and exit

12 Structs

  1. Struct definition
  2. Creating an instance
  3. Tuple struct
  4. Unit-like struct
  5. Field update
  6. Summary - Structs

13 Methods

  1. impl block
  2. self parameter
  3. &mut self
  4. Associated functions
  5. Multiple impl blocks
  6. Summary - Methods

14 Enums

  1. Enum definition
  2. Variants
  3. Variants with data
  4. Option<T>
  5. Option instead of null
  6. Summary - Enums

15 Pattern matching

  1. match patterns
  2. Value binding
  3. if let
  4. while let
  5. _ wildcard
  6. Summary - Pattern matching

16 Project: To-do CLI

  1. Task model
  2. Adding
  3. Listing
  4. Marking done
  5. Reading commands

17 Vectors

  1. Vec<T>
  2. Push and pop
  3. Index and get
  4. Looping a vector
  5. with_capacity
  6. Summary - Vectors

18 Advanced strings

  1. String and &str conversion
  2. chars and bytes
  3. Slicing strings
  4. contains and replace
  5. split and join
  6. Summary - Advanced strings

19 Error handling

  1. Result<T, E>
  2. panic!
  3. ? operator
  4. match and Result
  5. unwrap and expect
  6. Summary - Error handling

20 Beginner final

  1. Vowel counter
  2. Average calculator
  3. Bank account
  4. Temperature converter