release: 4.5.0

Signed-off-by: ana <ana@ana.st>

.all-contributorsrc

@@ -838,6 +838,97 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "stoiandan",
+      "name": "Stoian Dan",
+      "avatar_url": "https://avatars.githubusercontent.com/u/10388612?v=4",
+      "profile": "https://github.com/stoiandan",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "PiDelport",
+      "name": "Pi Delport",
+      "avatar_url": "https://avatars.githubusercontent.com/u/630271?v=4",
+      "profile": "https://about.me/pjdelport",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "sateeshkumarb",
+      "name": "Sateesh ",
+      "avatar_url": "https://avatars.githubusercontent.com/u/429263?v=4",
+      "profile": "https://github.com/sateeshkumarb",
+      "contributions": [
+        "code",
+        "content"
+      ]
+    },
+    {
+      "login": "kayuapi",
+      "name": "ZC",
+      "avatar_url": "https://avatars.githubusercontent.com/u/10304328?v=4",
+      "profile": "https://github.com/kayuapi",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "hyperparabolic",
+      "name": "hyperparabolic",
+      "avatar_url": "https://avatars.githubusercontent.com/u/12348474?v=4",
+      "profile": "https://github.com/hyperparabolic",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "kolbma",
+      "name": "arlecchino",
+      "avatar_url": "https://avatars.githubusercontent.com/u/5228369?v=4",
+      "profile": "https://www.net4visions.at",
+      "contributions": [
+        "doc"
+      ]
+    },
+    {
+      "login": "jazzplato",
+      "name": "Richthofen",
+      "avatar_url": "https://avatars.githubusercontent.com/u/7576730?v=4",
+      "profile": "https://richthofen.io/",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "cseltol",
+      "name": "Ivan Nerazumov",
+      "avatar_url": "https://avatars.githubusercontent.com/u/64264529?v=4",
+      "profile": "https://github.com/cseltol",
+      "contributions": [
+        "doc"
+      ]
+    },
+    {
+      "login": "lauralindzey",
+      "name": "lauralindzey",
+      "avatar_url": "https://avatars.githubusercontent.com/u/65185744?v=4",
+      "profile": "https://github.com/lauralindzey",
+      "contributions": [
+        "doc"
+      ]
+    },
+    {
+      "login": "sinharaksh1t",
+      "name": "Rakshit Sinha",
+      "avatar_url": "https://avatars.githubusercontent.com/u/28585848?v=4",
+      "profile": "https://github.com/sinharaksh1t",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,

CHANGELOG.md

@@ -1,3 +1,27 @@
+<a name="4.5.0"></a>
+## 4.5.0 (2021-07-07)
+
+
+#### Features
+
+*   Add move_semantics5 exercise. (#746) ([399ab328](https://github.com/rust-lang/rustlings/commit/399ab328d8d407265c09563aa4ef4534b2503ff2))
+* **cli:**  Add "next" to run the next unsolved exercise. (#785) ([d20e413a](https://github.com/rust-lang/rustlings/commit/d20e413a68772cd493561f2651cf244e822b7ca5))
+
+#### Bug Fixes
+
+*   rename result1 to errors4 ([50ab289d](https://github.com/rust-lang/rustlings/commit/50ab289da6b9eb19a7486c341b00048c516b88c0))
+*   move_semantics5 hints ([1b858285](https://github.com/rust-lang/rustlings/commit/1b85828548f46f58b622b5e0c00f8c989f928807))
+*   remove trailing whitespaces from iterators1 ([4d4fa774](https://github.com/rust-lang/rustlings/commit/4d4fa77459392acd3581c6068aa8be9a02de12fc))
+*   add hints to generics1 and generics2 exercises ([31457940](https://github.com/rust-lang/rustlings/commit/31457940846b3844d78d4a4d2b074bc8d6aaf1eb))
+*   remove trailing whitespace ([d9b69bd1](https://github.com/rust-lang/rustlings/commit/d9b69bd1a0a7a99f2c0d80933ad2eea44c8c71b2))
+* **installation:**  first PowerShell command ([aa9a943d](https://github.com/rust-lang/rustlings/commit/aa9a943ddf3ae260782e73c26bcc9db60e5894b6))
+* **iterators5:**  derive Clone, Copy ([91fc9e31](https://github.com/rust-lang/rustlings/commit/91fc9e3118f4af603c9911698cc2a234725cb032))
+* **quiz1:**  Updated question description (#794) ([d8766496](https://github.com/rust-lang/rustlings/commit/d876649616cc8a8dd5f539f8bc1a5434b960b1e9))
+* **try_from_into, from_str:**  hints for dyn Error ([11d2cf0d](https://github.com/rust-lang/rustlings/commit/11d2cf0d604dee3f5023c17802d69438e69fa50e))
+* **variables5:**  confine the answer further ([48ffcbd2](https://github.com/rust-lang/rustlings/commit/48ffcbd2c4cc4d936c2c7480019190f179813cc5))
+
+
+
 <a name="4.4.0"></a>
 ## 4.4.0 (2021-04-24)
 

Cargo.lock

@@ -539,7 +539,7 @@ checksum = "24d5f089152e60f62d28b835fbff2cd2e8dc0baf1ac13343bef92ab7eed84548"
 
 [[package]]
 name = "rustlings"
-version = "4.4.0"
+version = "4.5.0"
 dependencies = [
  "argh",
  "assert_cmd",

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "rustlings"
-version = "4.4.0"
-authors = ["Marisa <mokou@posteo.de>", "Carol (Nichols || Goulding) <carol.nichols@gmail.com>"]
+version = "4.5.0"
+authors = ["anastasie <ana@ana.st>", "Carol (Nichols || Goulding) <carol.nichols@gmail.com>"]
 edition = "2018"
 
 [dependencies]

README.md

@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-90-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-100-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -33,10 +33,10 @@ This will install Rustlings and give you access to the `rustlings` command. Run
 
 ## Windows
 
-In PowerShell, set `ExecutionPolicy` to `RemoteSigned`:
+In PowerShell (Run as Administrator), set `ExecutionPolicy` to `RemoteSigned`:
 
 ```ps
-Set-ExecutionPolicy RemoteSigned
+Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser
 ```
 
 Then, you can run:
@@ -57,12 +57,12 @@ When you get a permission denied message then you have to exclude the directory
 
 ## Manually
 
-Basically: Clone the repository, checkout to the latest tag, run `cargo install`.
+Basically: Clone the repository at the latest tag, run `cargo install`.
 
 ```bash
-git clone https://github.com/rust-lang/rustlings
+# find out the latest version at https://github.com/rust-lang/rustlings/releases/latest (on edit 4.5.0)
+git clone -b 4.5.0 --depth 1 https://github.com/rust-lang/rustlings
 cd rustlings
-git checkout tags/4.4.0 # or whatever the latest version is (find out at https://github.com/rust-lang/rustlings/releases/latest)
 cargo install --force --path .
 ```
 
@@ -97,6 +97,12 @@ In case you want to go by your own order, or want to only verify a single exerci
 rustlings run myExercise1
 ```
 
+Or simply use the following command to run the next unsolved exercise in the course:
+
+```bash
+rustlings run next
+```
+
 In case you get stuck, you can run the following command to get a hint for your
 exercise:
 
@@ -104,6 +110,12 @@ exercise:
 rustlings hint myExercise1
 ```
 
+You can also get the hint for the next unsolved exercise with the following command:
+
+``` bash
+rustlings hint next
+```
+
 To check your progress, you can run the following command:
 ```bash
 rustlings list
@@ -278,6 +290,18 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
   <tr>
     <td align="center"><a href="https://github.com/hongshaoyang"><img src="https://avatars.githubusercontent.com/u/19281800?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Shao Yang Hong</b></sub></a><br /><a href="#content-hongshaoyang" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/bmacer"><img src="https://avatars.githubusercontent.com/u/13931806?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Brandon Macer</b></sub></a><br /><a href="#content-bmacer" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/stoiandan"><img src="https://avatars.githubusercontent.com/u/10388612?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Stoian Dan</b></sub></a><br /><a href="#content-stoiandan" title="Content">🖋</a></td>
+    <td align="center"><a href="https://about.me/pjdelport"><img src="https://avatars.githubusercontent.com/u/630271?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Pi Delport</b></sub></a><br /><a href="#content-PiDelport" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/sateeshkumarb"><img src="https://avatars.githubusercontent.com/u/429263?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Sateesh </b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=sateeshkumarb" title="Code">💻</a> <a href="#content-sateeshkumarb" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/kayuapi"><img src="https://avatars.githubusercontent.com/u/10304328?v=4?s=100" width="100px;" alt=""/><br /><sub><b>ZC</b></sub></a><br /><a href="#content-kayuapi" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/hyperparabolic"><img src="https://avatars.githubusercontent.com/u/12348474?v=4?s=100" width="100px;" alt=""/><br /><sub><b>hyperparabolic</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=hyperparabolic" title="Code">💻</a></td>
+    <td align="center"><a href="https://www.net4visions.at"><img src="https://avatars.githubusercontent.com/u/5228369?v=4?s=100" width="100px;" alt=""/><br /><sub><b>arlecchino</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=kolbma" title="Documentation">📖</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://richthofen.io/"><img src="https://avatars.githubusercontent.com/u/7576730?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Richthofen</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=jazzplato" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/cseltol"><img src="https://avatars.githubusercontent.com/u/64264529?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Ivan Nerazumov</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=cseltol" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://github.com/lauralindzey"><img src="https://avatars.githubusercontent.com/u/65185744?v=4?s=100" width="100px;" alt=""/><br /><sub><b>lauralindzey</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=lauralindzey" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://github.com/sinharaksh1t"><img src="https://avatars.githubusercontent.com/u/28585848?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Rakshit Sinha</b></sub></a><br /><a href="#content-sinharaksh1t" title="Content">🖋</a></td>
   </tr>
 </table>
 

exercises/README.md

@@ -10,7 +10,7 @@
 | structs                | §5.1          |
 | enums                  | §6            |
 | modules                | §7.2          |
-| collections            | §8.1          |
+| collections            | §8.1, §8.3    |
 | strings                | §8.2          |
 | error_handling         | §9            |
 | generics               | §10           |

exercises/collections/README.md

@@ -20,3 +20,4 @@ structures that are used very often in Rust programs:
 ## Further information
 
 - [Storing Lists of Values with Vectors](https://doc.rust-lang.org/stable/book/ch08-01-vectors.html)
+- [Storing Keys with Associated Values in Hash Maps](https://doc.rust-lang.org/book/ch08-03-hash-maps.html)

exercises/error_handling/errors4.rs

@@ -1,5 +1,5 @@
-// result1.rs
-// Make this test pass! Execute `rustlings hint result1` for hints :)
+// errors4.rs
+// Make this test pass! Execute `rustlings hint errors4` for hints :)
 
 // I AM NOT DONE
 

exercises/error_handling/errors5.rs

@@ -0,0 +1,53 @@
+// errors5.rs
+
+// This program uses a completed version of the code from errors4.
+// It won't compile right now! Why?
+// Execute `rustlings hint errors5` for hints!
+
+// I AM NOT DONE
+
+use std::error;
+use std::fmt;
+use std::num::ParseIntError;
+
+// TODO: update the return type of `main()` to make this compile.
+fn main() -> Result<(), ParseIntError> {
+    let pretend_user_input = "42";
+    let x: i64 = pretend_user_input.parse()?;
+    println!("output={:?}", PositiveNonzeroInteger::new(x)?);
+    Ok(())
+}
+
+// Don't change anything below this line.
+
+#[derive(PartialEq, Debug)]
+struct PositiveNonzeroInteger(u64);
+
+#[derive(PartialEq, Debug)]
+enum CreationError {
+    Negative,
+    Zero,
+}
+
+impl PositiveNonzeroInteger {
+    fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
+        match value {
+            x if x < 0 => Err(CreationError::Negative),
+            x if x == 0 => Err(CreationError::Zero),
+            x => Ok(PositiveNonzeroInteger(x as u64))
+        }
+    }
+}
+
+// This is required so that `CreationError` can implement `error::Error`.
+impl fmt::Display for CreationError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let description = match *self {
+            CreationError::Negative => "number is negative",
+            CreationError::Zero => "number is zero",
+        };
+        f.write_str(description)
+    }
+}
+
+impl error::Error for CreationError {}

exercises/error_handling/errors6.rs

@@ -0,0 +1,95 @@
+// errors6.rs
+
+// Using catch-all error types like `Box<dyn error::Error>` isn't recommended
+// for library code, where callers might want to make decisions based on the
+// error content, instead of printing it out or propagating it further. Here,
+// we define a custom error type to make it possible for callers to decide
+// what to do next when our function returns an error.
+
+// Make these tests pass! Execute `rustlings hint errors6` for hints :)
+
+// I AM NOT DONE
+
+use std::num::ParseIntError;
+
+// This is a custom error type that we will be using in `parse_pos_nonzero()`.
+#[derive(PartialEq, Debug)]
+enum ParsePosNonzeroError {
+    Creation(CreationError),
+    ParseInt(ParseIntError)
+}
+
+impl ParsePosNonzeroError {
+    fn from_creation(err: CreationError) -> ParsePosNonzeroError {
+        ParsePosNonzeroError::Creation(err)
+    }
+    // TODO: add another error conversion function here.
+}
+
+fn parse_pos_nonzero(s: &str)
+    -> Result<PositiveNonzeroInteger, ParsePosNonzeroError>
+{
+    // TODO: change this to return an appropriate error instead of panicking
+    // when `parse()` returns an error.
+    let x: i64 = s.parse().unwrap();
+    PositiveNonzeroInteger::new(x)
+        .map_err(ParsePosNonzeroError::from_creation)
+}
+
+// Don't change anything below this line.
+
+#[derive(PartialEq, Debug)]
+struct PositiveNonzeroInteger(u64);
+
+#[derive(PartialEq, Debug)]
+enum CreationError {
+    Negative,
+    Zero,
+}
+
+impl PositiveNonzeroInteger {
+    fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
+        match value {
+            x if x < 0 => Err(CreationError::Negative),
+            x if x == 0 => Err(CreationError::Zero),
+            x => Ok(PositiveNonzeroInteger(x as u64))
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_parse_error() {
+        // We can't construct a ParseIntError, so we have to pattern match.
+        assert!(matches!(
+            parse_pos_nonzero("not a number"),
+            Err(ParsePosNonzeroError::ParseInt(_))
+        ));
+    }
+
+    #[test]
+    fn test_negative() {
+        assert_eq!(
+            parse_pos_nonzero("-555"),
+            Err(ParsePosNonzeroError::Creation(CreationError::Negative))
+        );
+    }
+
+    #[test]
+    fn test_zero() {
+        assert_eq!(
+            parse_pos_nonzero("0"),
+            Err(ParsePosNonzeroError::Creation(CreationError::Zero))
+        );
+    }
+
+    #[test]
+    fn test_positive() {
+        let x = PositiveNonzeroInteger::new(42);
+        assert!(x.is_ok());
+        assert_eq!(parse_pos_nonzero("42"), Ok(x.unwrap()));
+    }
+}

exercises/error_handling/errorsn.rs

@@ -1,117 +0,0 @@
-// errorsn.rs
-// This is a bigger error exercise than the previous ones!
-// You can do it! :)
-//
-// Edit the `read_and_validate` function ONLY. Don't create any Errors
-// that do not already exist.
-//
-// So many things could go wrong!
-//
-// - Reading from stdin could produce an io::Error
-// - Parsing the input could produce a num::ParseIntError
-// - Validating the input could produce a CreationError (defined below)
-//
-// How can we lump these errors into one general error? That is, what
-// type goes where the question marks are, and how do we return
-// that type from the body of read_and_validate?
-//
-// Execute `rustlings hint errorsn` for hints :)
-
-// I AM NOT DONE
-
-use std::error;
-use std::fmt;
-use std::io;
-
-// PositiveNonzeroInteger is a struct defined below the tests.
-fn read_and_validate(b: &mut dyn io::BufRead) -> Result<PositiveNonzeroInteger, ???> {
-    let mut line = String::new();
-    b.read_line(&mut line);
-    let num: i64 = line.trim().parse();
-    let answer = PositiveNonzeroInteger::new(num);
-    answer
-}
-
-//
-// Nothing below this needs to be modified
-//
-
-// This is a test helper function that turns a &str into a BufReader.
-fn test_with_str(s: &str) -> Result<PositiveNonzeroInteger, Box<dyn error::Error>> {
-    let mut b = io::BufReader::new(s.as_bytes());
-    read_and_validate(&mut b)
-}
-
-#[test]
-fn test_success() {
-    let x = test_with_str("42\n");
-    assert_eq!(PositiveNonzeroInteger(42), x.unwrap());
-}
-
-#[test]
-fn test_not_num() {
-    let x = test_with_str("eleven billion\n");
-    assert!(x.is_err());
-}
-
-#[test]
-fn test_non_positive() {
-    let x = test_with_str("-40\n");
-    assert!(x.is_err());
-}
-
-#[test]
-fn test_ioerror() {
-    struct Broken;
-    impl io::Read for Broken {
-        fn read(&mut self, _buf: &mut [u8]) -> io::Result<usize> {
-            Err(io::Error::new(io::ErrorKind::BrokenPipe, "uh-oh!"))
-        }
-    }
-    let mut b = io::BufReader::new(Broken);
-    assert!(read_and_validate(&mut b).is_err());
-    assert_eq!("uh-oh!", read_and_validate(&mut b).unwrap_err().to_string());
-}
-
-#[derive(PartialEq, Debug)]
-struct PositiveNonzeroInteger(u64);
-
-impl PositiveNonzeroInteger {
-    fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
-        if value == 0 {
-            Err(CreationError::Zero)
-        } else if value < 0 {
-            Err(CreationError::Negative)
-        } else {
-            Ok(PositiveNonzeroInteger(value as u64))
-        }
-    }
-}
-
-#[test]
-fn test_positive_nonzero_integer_creation() {
-    assert!(PositiveNonzeroInteger::new(10).is_ok());
-    assert_eq!(
-        Err(CreationError::Negative),
-        PositiveNonzeroInteger::new(-10)
-    );
-    assert_eq!(Err(CreationError::Zero), PositiveNonzeroInteger::new(0));
-}
-
-#[derive(PartialEq, Debug)]
-enum CreationError {
-    Negative,
-    Zero,
-}
-
-impl fmt::Display for CreationError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let description = match *self {
-            CreationError::Negative => "Number is negative",
-            CreationError::Zero => "Number is zero",
-        };
-        f.write_str(description)
-    }
-}
-
-impl error::Error for CreationError {}

exercises/generics/generics1.rs

@@ -1,6 +1,8 @@
 // This shopping list program isn't compiling!
 // Use your knowledge of generics to fix it.
 
+// Execute `rustlings hint generics1` for hints!
+
 // I AM NOT DONE
 
 fn main() {

exercises/generics/generics2.rs

@@ -1,6 +1,8 @@
 // This powerful wrapper provides the ability to store a positive integer value.
 // Rewrite it using generics so that it supports wrapping ANY type.
 
+// Execute `rustlings hint generics2` for hints!
+
 // I AM NOT DONE
 
 struct Wrapper {

exercises/move_semantics/move_semantics5.rs

@@ -0,0 +1,15 @@
+// move_semantics5.rs
+// Make me compile without adding, removing, or changing any of the
+// lines in `main()`.
+// Execute `rustlings hint move_semantics5` for hints :)
+
+// I AM NOT DONE
+
+fn main() {
+    let mut x = 100;
+    let y = &mut x;
+    let z = &mut *y;
+    *y += 100;
+    *z += 1000;
+    assert_eq!(x, 1200);
+}

exercises/option/option3.rs

@@ -0,0 +1,19 @@
+// option3.rs
+// Make me compile! Execute `rustlings hint option3` for hints
+
+// I AM NOT DONE
+
+struct Point {
+    x: i32,
+    y: i32,
+}
+
+fn main() {
+    let y: Option<Point> = Some(Point { x: 100, y: 200 });
+
+    match y {
+        Some(p) => println!("Co-ordinates are {},{} ", p.x, p.y),
+        _ => println!("no match"),
+    }
+    y; // Fix without deleting this line.
+}

exercises/quiz1.rs

@@ -5,7 +5,7 @@
 
 // Mary is buying apples. One apple usually costs 2 Rustbucks, but if you buy
 // more than 40 at once, each apple only costs 1! Write a function that calculates
-// the price of an order of apples given the order amount. No hints this time!
+// the price of an order of apples given the quantity bought. No hints this time!
 
 // I AM NOT DONE
 
@@ -16,8 +16,10 @@
 #[test]
 fn verify_test() {
     let price1 = calculate_apple_price(35);
-    let price2 = calculate_apple_price(65);
+    let price2 = calculate_apple_price(40);
+    let price3 = calculate_apple_price(65);
 
     assert_eq!(70, price1);
-    assert_eq!(65, price2);
+    assert_eq!(80, price2);
+    assert_eq!(65, price3);
 }

exercises/standard_library_types/iterators1.rs

@@ -1,11 +1,11 @@
 // iterators1.rs
-// 
+//
 //  Make me compile by filling in the `???`s
 //
 // When performing operations on elements within a collection, iterators are essential.
-// This module helps you get familiar with the structure of using an iterator and 
+// This module helps you get familiar with the structure of using an iterator and
 // how to go through elements within an iterable collection.
-// 
+//
 // Execute `rustlings hint iterators1` for hints :D
 
 // I AM NOT DONE

exercises/standard_library_types/iterators5.rs

@@ -7,8 +7,7 @@
 // imperative style for loops. Recreate this counting functionality using
 // iterators. Only the two iterator methods (count_iterator and
 // count_collection_iterator) need to be modified.
-// Execute `rustlings hint
-// iterators5` for hints.
+// Execute `rustlings hint iterators5` for hints.
 //
 // Make the code compile and the tests pass.
 
@@ -16,7 +15,7 @@
 
 use std::collections::HashMap;
 
-#[derive(PartialEq, Eq)]
+#[derive(Clone, Copy, PartialEq, Eq)]
 enum Progress {
     None,
     Some,

exercises/structs/structs3.rs

@@ -31,7 +31,7 @@ impl Package {
     }
 
     fn get_fees(&self, cents_per_gram: i32) -> ??? {
-        // Something goes here... 
+        // Something goes here...
     }
 }
 

exercises/variables/variables5.rs

@@ -4,7 +4,7 @@
 // I AM NOT DONE
 
 fn main() {
-    let number = "T-H-R-E-E";
+    let number = "T-H-R-E-E"; // don't change this line
     println!("Spell a Number : {}", number);
     number = 3;
     println!("Number plus two is : {}", number + 2);

info.toml

@@ -210,6 +210,21 @@ So the end goal is to:
    - since we're not creating a new vec in `main` anymore, we need to create
      a new vec in `fill_vec`, similarly to the way we did in `main`"""
 
+[[exercises]]
+name = "move_semantics5"
+path = "exercises/move_semantics/move_semantics5.rs"
+mode = "compile"
+hint = """
+Carefully reason about the range in which each mutable reference is in
+vogue. Does it help to update the value of referent (x) immediately after
+the mutable reference is taken? Read more about 'Mutable References'
+in the book's section References and Borrowing':
+https://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html#mutable-references.
+
+Additional hint:
+If you can't add, change, or remove any statements in `main()`, can you
+reorder them in a way that lets the program compile?"""
+
 # PRIMITIVE TYPES
 
 [[exercises]]
@@ -475,42 +490,61 @@ hint = """
 If other functions can return a `Result`, why shouldn't `main`?"""
 
 [[exercises]]
-name = "errorsn"
-path = "exercises/error_handling/errorsn.rs"
+name = "errors4"
+path = "exercises/error_handling/errors4.rs"
 mode = "test"
 hint = """
-First hint: To figure out what type should go where the ??? is, take a look
-at the test helper function `test_with_str`, since it returns whatever
-`read_and_validate` returns and `test_with_str` has its signature fully
-specified.
-
-
-Next hint: There are three places in `read_and_validate` that we call a
-function that returns a `Result` (that is, the functions might fail).
-Apply the `?` operator on those calls so that we return immediately from
-`read_and_validate` if those function calls fail.
+`PositiveNonzeroInteger::new` is always creating a new instance and returning an `Ok` result.
+It should be doing some checking, returning an `Err` result if those checks fail, and only
+returning an `Ok` result if those checks determine that everything is... okay :)"""
 
+[[exercises]]
+name = "errors5"
+path = "exercises/error_handling/errors5.rs"
+mode = "compile"
+hint = """
+Hint: There are two different possible `Result` types produced within
+`main()`, which are propagated using `?` operators. How do we declare a
+return type from `main()` that allows both?
 
 Another hint: under the hood, the `?` operator calls `From::from`
-on the error value to convert it to a boxed trait object, a Box<dyn error::Error>,
-which is polymorphic-- that means that lots of different kinds of errors
-can be returned from the same function because all errors act the same
-since they all implement the `error::Error` trait.
+on the error value to convert it to a boxed trait object, a
+`Box<dyn error::Error>`, which is polymorphic-- that means that lots of
+different kinds of errors can be returned from the same function because
+all errors act the same since they all implement the `error::Error` trait.
 Check out this section of the book:
 https://doc.rust-lang.org/book/ch09-02-recoverable-errors-with-result.html#a-shortcut-for-propagating-errors-the--operator
 
+This exercise uses some concepts that we won't get to until later in the
+course, like `Box` and the `From` trait. It's not important to understand
+them in detail right now, but you can read ahead if you like.
 
-Another another hint: Note that because the `?` operator returns
-the *unwrapped* value in the `Ok` case, if we want to return a `Result` from
-`read_and_validate` for *its* success case, we'll have to rewrap a value
-that we got from the return value of a `?`ed call in an `Ok`-- this will
-look like `Ok(something)`.
+Read more about boxing errors:
+https://doc.rust-lang.org/stable/rust-by-example/error/multiple_error_types/boxing_errors.html
 
+Read more about using the `?` operator with boxed errors:
+https://doc.rust-lang.org/stable/rust-by-example/error/multiple_error_types/reenter_question_mark.html
+"""
 
-Another another another hint: `Result`s must be "used", that is, you'll
-get a warning if you don't handle a `Result` that you get in your
-function. Read more about that in the `std::result` module docs:
-https://doc.rust-lang.org/std/result/#results-must-be-used"""
+[[exercises]]
+name = "errors6"
+path = "exercises/error_handling/errors6.rs"
+mode = "test"
+hint = """
+This exercise uses a completed version of `PositiveNonzeroInteger` from
+errors4.
+
+Below the line that TODO asks you to change, there is an example of using
+the `map_err()` method on a `Result` to transform one type of error into
+another. Try using something similar on the `Result` from `parse()`. You
+might use the `?` operator to return early from the function, or you might
+use a `match` expression, or maybe there's another way!
+
+You can create another function inside `impl ParsePosNonzeroError` to use
+with `map_err()`.
+
+Read more about `map_err()` in the `std::result` documentation:
+https://doc.rust-lang.org/std/result/enum.Result.html#method.map_err"""
 
 # Generics
 
@@ -546,7 +580,7 @@ ReportCard struct generic, but also the correct property - you will need to chan
 of the struct slightly too...you can do it!
 """
 
-# OPTIONS / RESULTS
+# OPTIONS
 
 [[exercises]]
 name = "option1"
@@ -579,13 +613,14 @@ Also see Option::flatten
 """
 
 [[exercises]]
-name = "result1"
-path = "exercises/error_handling/result1.rs"
-mode = "test"
+name = "option3"
+path = "exercises/option/option3.rs"
+mode = "compile"
 hint = """
-`PositiveNonzeroInteger::new` is always creating a new instance and returning an `Ok` result.
-It should be doing some checking, returning an `Err` result if those checks fail, and only
-returning an `Ok` result if those checks determine that everything is... okay :)"""
+The compiler says a partial move happened in the `match`
+statement. How can this be avoided? The compiler shows the correction
+needed. After making the correction as suggested by the compiler, do
+read: https://doc.rust-lang.org/std/keyword.ref.html"""
 
 # TRAITS
 
@@ -737,7 +772,10 @@ The division_results variable needs to be collected into a collection type.
 The result_with_list function needs to return a single Result where the success
 case is a vector of integers and the failure case is a DivisionError.
 
-The list_of_results function needs to return a vector of results."""
+The list_of_results function needs to return a vector of results.
+
+See https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.collect for how 
+the `FromIterator` trait is used in `collect()`."""
 
 [[exercises]]
 name = "iterators4"
@@ -763,7 +801,10 @@ test count_iterator.
 The collection variable in count_collection_iterator is a slice of HashMaps. It
 needs to be converted into an iterator in order to use the iterator methods.
 
-The fold method can be useful in the count_collection_iterator function."""
+The fold method can be useful in the count_collection_iterator function.
+
+For a further challenge, consult the documentation for Iterator to find
+a different method that could make your code more compact than using fold."""
 
 # THREADS
 
@@ -861,7 +902,15 @@ name = "clippy1"
 path = "exercises/clippy/clippy1.rs"
 mode = "clippy"
 hint = """
-Floating point calculations are usually imprecise, so asking if two values are exactly equal is asking for trouble"""
+Not every floating point value can be represented exactly in binary values in
+memory. Take a look at the description of 
+https://doc.rust-lang.org/stable/std/primitive.f32.html
+When using the binary compare operators with floating points you won't compare
+the floating point values but the binary representation in memory. This is 
+usually not what you would like to do. 
+See the suggestions of the clippy warning in compile output and use the
+machine epsilon value...
+https://doc.rust-lang.org/stable/std/primitive.f32.html#associatedconstant.EPSILON"""
 
 [[exercises]]
 name = "clippy2"
@@ -893,7 +942,19 @@ path = "exercises/conversions/try_from_into.rs"
 mode = "test"
 hint = """
 Follow the steps provided right before the `TryFrom` implementation.
-You can also use the example at https://doc.rust-lang.org/std/convert/trait.TryFrom.html"""
+You can also use the example at https://doc.rust-lang.org/std/convert/trait.TryFrom.html
+
+You might want to look back at the exercise errors5 (or its hints) to remind
+yourself about how `Box<dyn Error>` works.
+
+If you're trying to return a string as an error, note that neither `str`
+nor `String` implements `error::Error`. However, there is an implementation
+of `From<&str>` for `Box<dyn Error>`. This means you can use `.into()` or
+the `?` operator to convert your string into the correct error type.
+
+If you're having trouble with using the `?` operator to convert an error string,
+recall that `?` works to convert `Err(something)` into the appropriate error
+type for returning from the function."""
 
 [[exercises]]
 name = "as_ref_mut"
@@ -909,4 +970,7 @@ mode = "test"
 hint = """
 The implementation of FromStr should return an Ok with a Person object,
 or an Err with an error if the string is not valid.
-This is almost like the `try_from_into` exercise."""
+This is almost like the `try_from_into` exercise.
+
+If you're having trouble with returning the correct error type, see the
+hints for try_from_into."""

src/main.rs

@@ -23,7 +23,7 @@ mod run;
 mod verify;
 
 // In sync with crate version
-const VERSION: &str = "4.4.0";
+const VERSION: &str = "4.5.0";
 
 #[derive(FromArgs, PartialEq, Debug)]
 /// Rustlings is a collection of small exercises to get you used to writing and reading Rust code
@@ -286,13 +286,24 @@ fn spawn_watch_shell(failed_exercise_hint: &Arc<Mutex<Option<String>>>) {
 }
 
 fn find_exercise<'a>(name: &str, exercises: &'a [Exercise]) -> &'a Exercise {
-    exercises
-        .iter()
-        .find(|e| e.name == name)
-        .unwrap_or_else(|| {
-            println!("No exercise found for '{}'!", name);
-            std::process::exit(1)
-        })
+    if name.eq("next") {
+        exercises
+            .iter()
+            .find(|e| !e.looks_done())
+            .unwrap_or_else(|| {
+                println!("🎉 Congratulations! You have done all the exercises!");
+                println!("🔚 There are no more exercises to do next!");
+                std::process::exit(1)
+            })
+    } else {
+        exercises
+            .iter()
+            .find(|e| e.name == name)
+            .unwrap_or_else(|| {
+                println!("No exercise found for '{}'!", name);
+                std::process::exit(1)
+            })
+    }
 }
 
 fn watch(exercises: &[Exercise], verbose: bool) -> notify::Result<()> {