Use todo!() instead of unimplemented!()

The difference is one of intent, and the actual panic message.
See the docs why todo is more appropriate:
https://doc.rust-lang.org/stable/std/macro.todo.html

[no important files changed]

closes #1598

concepts/structs/about.md

@@ -32,7 +32,7 @@ Lastly, methods can be defined on structs inside of an `impl` block:
 impl Item {
     // initializes and returns a new instance of our Item struct
     fn new() -> Self {
-        unimplemented!()
+        todo!()
     }
 }
 ```

exercises/concept/assembly-line/src/lib.rs

@@ -1,7 +1,7 @@
 pub fn production_rate_per_hour(speed: u8) -> f64 {
-    unimplemented!("calculate hourly production rate at speed: {speed}")
+    todo!("calculate hourly production rate at speed: {speed}")
 }
 
 pub fn working_items_per_minute(speed: u8) -> u32 {
-    unimplemented!("calculate the amount of working items at speed: {speed}")
+    todo!("calculate the amount of working items at speed: {speed}")
 }

exercises/concept/csv-builder/src/lib.rs

@@ -9,16 +9,16 @@ pub struct CsvRecordBuilder {
 impl CsvRecordBuilder {
     // Create a new builder
     pub fn new() -> Self {
-        unimplemented!("implement the `CsvRecordBuilder::new` method")
+        todo!("implement the `CsvRecordBuilder::new` method")
     }
 
     /// Adds an item to the list separated by a space and a comma.
     pub fn add(&mut self, val: &str) {
-        unimplemented!("implement the `CsvRecordBuilder::add` method, adding {val}")
+        todo!("implement the `CsvRecordBuilder::add` method, adding {val}")
     }
 
     /// Consumes the builder and returns the comma separated list
     pub fn build(self) -> String {
-        unimplemented!("implement the `CsvRecordBuilder::build` method")
+        todo!("implement the `CsvRecordBuilder::build` method")
     }
 }

exercises/concept/health-statistics/.docs/introduction.md

@@ -32,7 +32,7 @@ Lastly, methods can be defined on structs inside of an `impl` block:
 impl Item {
     // initializes and returns a new instance of our Item struct
     fn new() -> Self {
-        unimplemented!()
+        todo!()
     }
 }
 ```

exercises/concept/health-statistics/src/lib.rs

@@ -10,26 +10,26 @@ pub struct User {
 
 impl User {
     pub fn new(name: String, age: u32, weight: f32) -> Self {
-        unimplemented!()
+        todo!()
     }
 
     pub fn name(&self) -> &str {
-        unimplemented!()
+        todo!()
     }
 
     pub fn age(&self) -> u32 {
-        unimplemented!()
+        todo!()
     }
 
     pub fn weight(&self) -> f32 {
-        unimplemented!()
+        todo!()
     }
 
     pub fn set_age(&mut self, new_age: u32) {
-        unimplemented!()
+        todo!()
     }
 
     pub fn set_weight(&mut self, new_weight: f32) {
-        unimplemented!()
+        todo!()
     }
 }

exercises/concept/low-power-embedded-game/.docs/hints.md

@@ -18,6 +18,6 @@
 
 ## 3. Implement a `manhattan` method on a `Position` tuple struct
 
-- Don't worry about method syntax; just replacing the `unimplemented` portion within the `impl Position` block will do the right thing.
+- Don't worry about method syntax; just replacing the `todo` portion within the `impl Position` block will do the right thing.
 - Consider that some values within a `Position` may be negative, but a distance is never negative.
 - Calculating the absolute value is [built-in](https://doc.rust-lang.org/std/primitive.i16.html#method.abs)

exercises/concept/low-power-embedded-game/src/lib.rs

@@ -3,11 +3,11 @@
 #![allow(unused)]
 
 pub fn divmod(dividend: i16, divisor: i16) -> (i16, i16) {
-    unimplemented!("implement `fn divmod`");
+    todo!("implement `fn divmod`");
 }
 
 pub fn evens<T>(iter: impl Iterator<Item = T>) -> impl Iterator<Item = T> {
-    unimplemented!("implement `fn evens`");
+    todo!("implement `fn evens`");
     // TODO: remove this; it's only necessary to allow this function to compile
     // before the student has done any work.
     std::iter::empty()
@@ -16,6 +16,6 @@ pub fn evens<T>(iter: impl Iterator<Item = T>) -> impl Iterator<Item = T> {
 pub struct Position(pub i16, pub i16);
 impl Position {
     pub fn manhattan(&self) -> i16 {
-        unimplemented!("implement `fn manhattan`")
+        todo!("implement `fn manhattan`")
     }
 }

exercises/concept/lucians-luscious-lasagna/src/lib.rs

@@ -1,19 +1,19 @@
 pub fn expected_minutes_in_oven() -> i32 {
-    unimplemented!("return expected minutes in the oven")
+    todo!("return expected minutes in the oven")
 }
 
 pub fn remaining_minutes_in_oven(actual_minutes_in_oven: i32) -> i32 {
-    unimplemented!(
+    todo!(
         "calculate remaining minutes in oven given actual minutes in oven: {actual_minutes_in_oven}"
     )
 }
 
 pub fn preparation_time_in_minutes(number_of_layers: i32) -> i32 {
-    unimplemented!("calculate preparation time in minutes for number of layers: {number_of_layers}")
+    todo!("calculate preparation time in minutes for number of layers: {number_of_layers}")
 }
 
 pub fn elapsed_time_in_minutes(number_of_layers: i32, actual_minutes_in_oven: i32) -> i32 {
-    unimplemented!(
+    todo!(
         "calculate elapsed time in minutes for number of layers {number_of_layers} and actual minutes in oven {actual_minutes_in_oven}"
     )
 }

exercises/concept/magazine-cutout/.docs/instructions.md

@@ -13,7 +13,7 @@ You'll start with the following stubbed function signature:
 
 ```rust
 pub fn can_construct_note(magazine: &[&str], note: &[&str]) -> bool {
-    unimplemented!()
+    todo!()
 }
 ```
 

exercises/concept/magazine-cutout/src/lib.rs

@@ -5,5 +5,5 @@
 use std::collections::HashMap;
 
 pub fn can_construct_note(magazine: &[&str], note: &[&str]) -> bool {
-    unimplemented!()
+    todo!()
 }

exercises/concept/resistor-color/src/lib.rs

@@ -13,13 +13,13 @@ pub enum ResistorColor {
 }
 
 pub fn color_to_value(color: ResistorColor) -> u32 {
-    unimplemented!("convert color {color:?} into a numerical representation")
+    todo!("convert color {color:?} into a numerical representation")
 }
 
 pub fn value_to_color_string(value: u32) -> String {
-    unimplemented!("convert the value {value} into a string representation of color")
+    todo!("convert the value {value} into a string representation of color")
 }
 
 pub fn colors() -> Vec<ResistorColor> {
-    unimplemented!("return a list of all the colors ordered by resistance")
+    todo!("return a list of all the colors ordered by resistance")
 }

exercises/concept/role-playing-game/src/lib.rs

@@ -6,10 +6,10 @@ pub struct Player {
 
 impl Player {
     pub fn revive(&self) -> Option<Player> {
-        unimplemented!("Revive this player")
+        todo!("Revive this player")
     }
 
     pub fn cast_spell(&mut self, mana_cost: u32) -> u32 {
-        unimplemented!("Cast a spell of cost {mana_cost}")
+        todo!("Cast a spell of cost {mana_cost}")
     }
 }

exercises/concept/rpn-calculator/.docs/instructions.md

@@ -105,7 +105,7 @@ pub enum CalculatorInput {
 }
 
 pub fn evaluate(inputs: &[CalculatorInput]) -> Option<i32> {
-    unimplemented!(
+    todo!(
         "Given the inputs: {inputs:?}, evaluate them as though they were a Reverse Polish notation expression"
     );
 }

exercises/concept/rpn-calculator/src/lib.rs

@@ -8,7 +8,7 @@ pub enum CalculatorInput {
 }
 
 pub fn evaluate(inputs: &[CalculatorInput]) -> Option<i32> {
-    unimplemented!(
+    todo!(
         "Given the inputs: {inputs:?}, evaluate them as though they were a Reverse Polish notation expression"
     );
 }

exercises/concept/semi-structured-logs/src/lib.rs

@@ -11,14 +11,14 @@ pub enum LogLevel {
 }
 /// primary function for emitting logs
 pub fn log(level: LogLevel, message: &str) -> String {
-    unimplemented!("return a message for the given log level")
+    todo!("return a message for the given log level")
 }
 pub fn info(message: &str) -> String {
-    unimplemented!("return a message for info log level")
+    todo!("return a message for info log level")
 }
 pub fn warn(message: &str) -> String {
-    unimplemented!("return a message for warn log level")
+    todo!("return a message for warn log level")
 }
 pub fn error(message: &str) -> String {
-    unimplemented!("return a message for error log level")
+    todo!("return a message for error log level")
 }

exercises/concept/short-fibonacci/src/lib.rs

@@ -1,19 +1,19 @@
 /// Create an empty vector
 pub fn create_empty() -> Vec<u8> {
-    unimplemented!()
+    todo!()
 }
 
 /// Create a buffer of `count` zeroes.
 ///
 /// Applications often use buffers when serializing data to send over the network.
 pub fn create_buffer(count: usize) -> Vec<u8> {
-    unimplemented!("create a zeroized buffer of {count} bytes")
+    todo!("create a zeroized buffer of {count} bytes")
 }
 
 /// Create a vector containing the first five elements of the Fibonacci sequence.
 ///
 /// Fibonacci's sequence is the list of numbers where the next number is a sum of the previous two.
 /// Its first five elements are `1, 1, 2, 3, 5`.
 pub fn fibonacci() -> Vec<u8> {
-    unimplemented!()
+    todo!()
 }

exercises/practice/accumulate/src/lib.rs

@@ -1,4 +1,4 @@
 /// What should the type of _function be?
 pub fn map(input: Vec<i32>, _function: ???) -> Vec<i32> {
-    unimplemented!("Transform input vector {input:?} using passed function");
+    todo!("Transform input vector {input:?} using passed function");
 }

exercises/practice/acronym/src/lib.rs

@@ -1,3 +1,3 @@
 pub fn abbreviate(phrase: &str) -> String {
-    unimplemented!("Given the phrase '{phrase}', return its acronym");
+    todo!("Given the phrase '{phrase}', return its acronym");
 }

exercises/practice/affine-cipher/src/lib.rs

@@ -8,11 +8,11 @@ pub enum AffineCipherError {
 /// Encodes the plaintext using the affine cipher with key (`a`, `b`). Note that, rather than
 /// returning a return code, the more common convention in Rust is to return a `Result`.
 pub fn encode(plaintext: &str, a: i32, b: i32) -> Result<String, AffineCipherError> {
-    unimplemented!("Encode {plaintext} with the key ({a}, {b})");
+    todo!("Encode {plaintext} with the key ({a}, {b})");
 }
 
 /// Decodes the ciphertext using the affine cipher with key (`a`, `b`). Note that, rather than
 /// returning a return code, the more common convention in Rust is to return a `Result`.
 pub fn decode(ciphertext: &str, a: i32, b: i32) -> Result<String, AffineCipherError> {
-    unimplemented!("Decode {ciphertext} with the key ({a}, {b})");
+    todo!("Decode {ciphertext} with the key ({a}, {b})");
 }

exercises/practice/all-your-base/src/lib.rs

@@ -37,5 +37,5 @@ pub enum Error {
 ///    However, your function must be able to process input with leading 0 digits.
 ///
 pub fn convert(number: &[u32], from_base: u32, to_base: u32) -> Result<Vec<u32>, Error> {
-    unimplemented!("Convert {number:?} from base {from_base} to base {to_base}")
+    todo!("Convert {number:?} from base {from_base} to base {to_base}")
 }

exercises/practice/allergies/src/lib.rs

@@ -14,14 +14,14 @@ pub enum Allergen {
 
 impl Allergies {
     pub fn new(score: u32) -> Self {
-        unimplemented!("Given the '{score}' score, construct a new Allergies struct.");
+        todo!("Given the '{score}' score, construct a new Allergies struct.");
     }
 
     pub fn is_allergic_to(&self, allergen: &Allergen) -> bool {
-        unimplemented!("Determine if the patient is allergic to the '{allergen:?}' allergen.");
+        todo!("Determine if the patient is allergic to the '{allergen:?}' allergen.");
     }
 
     pub fn allergies(&self) -> Vec<Allergen> {
-        unimplemented!("Return the list of allergens contained within the score with which the Allergies struct was made.");
+        todo!("Return the list of allergens contained within the score with which the Allergies struct was made.");
     }
 }

exercises/practice/alphametics/src/lib.rs

@@ -1,5 +1,5 @@
 use std::collections::HashMap;
 
 pub fn solve(input: &str) -> Option<HashMap<char, u8>> {
-    unimplemented!("Solve the alphametic {input:?}")
+    todo!("Solve the alphametic {input:?}")
 }

exercises/practice/anagram/src/lib.rs

@@ -1,7 +1,5 @@
 use std::collections::HashSet;
 
 pub fn anagrams_for<'a>(word: &str, possible_anagrams: &[&str]) -> HashSet<&'a str> {
-    unimplemented!(
-        "For the '{word}' word find anagrams among the following words: {possible_anagrams:?}"
-    );
+    todo!("For the '{word}' word find anagrams among the following words: {possible_anagrams:?}");
 }

exercises/practice/armstrong-numbers/src/lib.rs

@@ -1,3 +1,3 @@
 pub fn is_armstrong_number(num: u32) -> bool {
-    unimplemented!("true if {num} is an armstrong number")
+    todo!("true if {num} is an armstrong number")
 }

exercises/practice/atbash-cipher/src/lib.rs

@@ -1,9 +1,9 @@
 /// "Encipher" with the Atbash cipher.
 pub fn encode(plain: &str) -> String {
-    unimplemented!("Encoding of {plain:?} in Atbash cipher.");
+    todo!("Encoding of {plain:?} in Atbash cipher.");
 }
 
 /// "Decipher" with the Atbash cipher.
 pub fn decode(cipher: &str) -> String {
-    unimplemented!("Decoding of {cipher:?} in Atbash cipher.");
+    todo!("Decoding of {cipher:?} in Atbash cipher.");
 }

exercises/practice/beer-song/src/lib.rs

@@ -1,7 +1,7 @@
 pub fn verse(n: u32) -> String {
-    unimplemented!("emit verse {n}")
+    todo!("emit verse {n}")
 }
 
 pub fn sing(start: u32, end: u32) -> String {
-    unimplemented!("sing verses {start} to {end}, inclusive")
+    todo!("sing verses {start} to {end}, inclusive")
 }

exercises/practice/binary-search/src/lib.rs

@@ -1,5 +1,5 @@
 pub fn find(array: &[i32], key: i32) -> Option<usize> {
-    unimplemented!(
+    todo!(
         "Using the binary search algorithm, find the element '{key}' in the array '{array:?}' and return its index."
     );
 }

exercises/practice/bob/src/lib.rs

@@ -1,3 +1,3 @@
 pub fn reply(message: &str) -> &str {
-    unimplemented!("have Bob reply to the incoming message: {message}")
+    todo!("have Bob reply to the incoming message: {message}")
 }

exercises/practice/book-store/src/lib.rs

@@ -1,3 +1,3 @@
 pub fn lowest_price(books: &[u32]) -> u32 {
-    unimplemented!("Find the lowest price of the bookbasket with books {books:?}")
+    todo!("Find the lowest price of the bookbasket with books {books:?}")
 }

exercises/practice/bowling/src/lib.rs

@@ -8,14 +8,14 @@ pub struct BowlingGame {}
 
 impl BowlingGame {
     pub fn new() -> Self {
-        unimplemented!();
+        todo!();
     }
 
     pub fn roll(&mut self, pins: u16) -> Result<(), Error> {
-        unimplemented!("Record that {pins} pins have been scored");
+        todo!("Record that {pins} pins have been scored");
     }
 
     pub fn score(&self) -> Option<u16> {
-        unimplemented!("Return the score if the game is complete, or None if not.");
+        todo!("Return the score if the game is complete, or None if not.");
     }
 }