diff --git a/exercises/README.md b/exercises/README.md new file mode 100644 index 00000000..725edd7b --- /dev/null +++ b/exercises/README.md @@ -0,0 +1,23 @@ +# Exercise to Book Chapter mapping + +| Exercise | Book Chapter | +|------------------------|--------------| +| variables | §3.1 | +| functions | §3.3 | +| if | §3.5 | +| move_semantics | §4.1 | +| primitive_types | §4.3 | +| structs | §5.1 | +| enums | §6 | +| modules | §7.2 | +| strings | §8.2 | +| error_handling | §9 | +| generics | §10 | +| option | §10.1 | +| traits | §10.2 | +| tests | §11.1 | +| standard_library_types | §13.2 | +| threads | §16.1 | +| macros | §19.6 | +| clippy | n/a | +| conversions | n/a | diff --git a/info.toml b/info.toml index cc12c99d..1b2eec21 100644 --- a/info.toml +++ b/info.toml @@ -71,31 +71,6 @@ Read more about constants under 'Differences Between Variables and Constants' in https://doc.rust-lang.org/book/ch03-01-variables-and-mutability.html#differences-between-variables-and-constants """ -# IF - -[[exercises]] -name = "if1" -path = "exercises/if/if1.rs" -mode = "test" -hint = """ -It's possible to do this in one line if you would like! -Some similar examples from other languages: -- In C(++) this would be: `a > b ? a : b` -- In Python this would be: `a if a > b else b` -Remember in Rust that: -- the `if` condition does not need to be surrounded by parentheses -- `if`/`else` conditionals are expressions -- Each condition is followed by a `{}` block.""" - -[[exercises]] -name = "if2" -path = "exercises/if/if2.rs" -mode = "test" -hint = """ -For that first compiler error, it's important in Rust that each conditional -block return the same type! To get the tests passing, you will need a couple -conditions checking different input values.""" - # FUNCTIONS [[exercises]] @@ -146,6 +121,31 @@ They are not the same. There are two solutions: 1. Add a `return` ahead of `num * num;` 2. remove `;`, make it to be `num * num`""" +# IF + +[[exercises]] +name = "if1" +path = "exercises/if/if1.rs" +mode = "test" +hint = """ +It's possible to do this in one line if you would like! +Some similar examples from other languages: +- In C(++) this would be: `a > b ? a : b` +- In Python this would be: `a if a > b else b` +Remember in Rust that: +- the `if` condition does not need to be surrounded by parentheses +- `if`/`else` conditionals are expressions +- Each condition is followed by a `{}` block.""" + +[[exercises]] +name = "if2" +path = "exercises/if/if2.rs" +mode = "test" +hint = """ +For that first compiler error, it's important in Rust that each conditional +block return the same type! To get the tests passing, you will need a couple +conditions checking different input values.""" + # TEST 1 [[exercises]] @@ -154,6 +154,62 @@ path = "exercises/quiz1.rs" mode = "test" hint = "No hints this time ;)" +# MOVE SEMANTICS + +[[exercises]] +name = "move_semantics1" +path = "exercises/move_semantics/move_semantics1.rs" +mode = "compile" +hint = """ +So you've got the "cannot borrow immutable local variable `vec1` as mutable" error on line 13, +right? The fix for this is going to be adding one keyword, and the addition is NOT on line 13 +where the error is.""" + +[[exercises]] +name = "move_semantics2" +path = "exercises/move_semantics/move_semantics2.rs" +mode = "compile" +hint = """ +So `vec0` is being *moved* into the function `fill_vec` when we call it on +line 10, which means it gets dropped at the end of `fill_vec`, which means we +can't use `vec0` again on line 13 (or anywhere else in `main` after the +`fill_vec` call for that matter). We could fix this in a few ways, try them +all! +1. Make another, separate version of the data that's in `vec0` and pass that + to `fill_vec` instead. +2. Make `fill_vec` borrow its argument instead of taking ownership of it, + and then copy the data within the function in order to return an owned + `Vec` +3. Make `fill_vec` *mutably* borrow its argument (which will need to be + mutable), modify it directly, then not return anything. Then you can get rid + of `vec1` entirely -- note that this will change what gets printed by the + first `println!`""" + +[[exercises]] +name = "move_semantics3" +path = "exercises/move_semantics/move_semantics3.rs" +mode = "compile" +hint = """ +The difference between this one and the previous ones is that the first line +of `fn fill_vec` that had `let mut vec = vec;` is no longer there. You can, +instead of adding that line back, add `mut` in one place that will change +an existing binding to be a mutable binding instead of an immutable one :)""" + +[[exercises]] +name = "move_semantics4" +path = "exercises/move_semantics/move_semantics4.rs" +mode = "compile" +hint = """ +Stop reading whenever you feel like you have enough direction :) Or try +doing one step and then fixing the compiler errors that result! +So the end goal is to: + - get rid of the first line in main that creates the new vector + - so then `vec0` doesn't exist, so we can't pass it to `fill_vec` + - we don't want to pass anything to `fill_vec`, so its signature should + reflect that it does not take any arguments + - 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`""" + # PRIMITIVE TYPES [[exercises]] @@ -255,6 +311,51 @@ For calculate_transport_fees: Bigger is more expensive usually, we don't have si Have a look in The Book, to find out more about method implementations: https://doc.rust-lang.org/book/ch05-03-method-syntax.html""" +# ENUMS + +[[exercises]] +name = "enums1" +path = "exercises/enums/enums1.rs" +mode = "compile" +hint = """ +Hint: The declaration of the enumeration type has not been defined yet.""" + +[[exercises]] +name = "enums2" +path = "exercises/enums/enums2.rs" +mode = "compile" +hint = """ +Hint: you can create enumerations that have different variants with different types +such as no data, anonymous structs, a single string, tuples, ...etc""" + +[[exercises]] +name = "enums3" +path = "exercises/enums/enums3.rs" +mode = "test" +hint = "No hints this time ;)" + +# MODULES + +[[exercises]] +name = "modules1" +path = "exercises/modules/modules1.rs" +mode = "compile" +hint = """ +Everything is private in Rust by default-- but there's a keyword we can use +to make something public! The compiler error should point to the thing that +needs to be public.""" + +[[exercises]] +name = "modules2" +path = "exercises/modules/modules2.rs" +mode = "compile" +hint = """ +The delicious_snacks module is trying to present an external +interface (the `fruit` and `veggie` constants) that is different than +its internal structure (the `fruits` and `veggies` modules and +associated constants). It's almost there except for one keyword missing for +each constant.""" + # STRINGS [[exercises]] @@ -286,248 +387,6 @@ path = "exercises/quiz2.rs" mode = "compile" hint = "No hints this time ;)" -# ENUMS - -[[exercises]] -name = "enums1" -path = "exercises/enums/enums1.rs" -mode = "compile" -hint = """ -Hint: The declaration of the enumeration type has not been defined yet.""" - -[[exercises]] -name = "enums2" -path = "exercises/enums/enums2.rs" -mode = "compile" -hint = """ -Hint: you can create enumerations that have different variants with different types -such as no data, anonymous structs, a single string, tuples, ...etc""" - -[[exercises]] -name = "enums3" -path = "exercises/enums/enums3.rs" -mode = "test" -hint = "No hints this time ;)" - -# TESTS - -[[exercises]] -name = "tests1" -path = "exercises/tests/tests1.rs" -mode = "test" -hint = """ -You don't even need to write any code to test -- you can just test values and run that, even -though you wouldn't do that in real life :) `assert!` is a macro that needs an argument. -Depending on the value of the argument, `assert!` will do nothing (in which case the test will -pass) or `assert!` will panic (in which case the test will fail). So try giving different values -to `assert!` and see which ones compile, which ones pass, and which ones fail :)""" - -[[exercises]] -name = "tests2" -path = "exercises/tests/tests2.rs" -mode = "test" -hint = """ -Like the previous exercise, you don't need to write any code to get this test to compile and -run. `assert_eq!` is a macro that takes two arguments and compares them. Try giving it two -values that are equal! Try giving it two arguments that are different! Try giving it two values -that are of different types! Try switching which argument comes first and which comes second!""" - -[[exercises]] -name = "tests3" -path = "exercises/tests/tests3.rs" -mode = "test" -hint = """ -You can call a function right where you're passing arguments to `assert!` -- so you could do -something like `assert!(having_fun())`. If you want to check that you indeed get false, you -can negate the result of what you're doing using `!`, like `assert!(!having_fun())`.""" - -# TEST 3 - -[[exercises]] -name = "quiz3" -path = "exercises/quiz3.rs" -mode = "test" -hint = "No hints this time ;)" - -# MODULES - -[[exercises]] -name = "modules1" -path = "exercises/modules/modules1.rs" -mode = "compile" -hint = """ -Everything is private in Rust by default-- but there's a keyword we can use -to make something public! The compiler error should point to the thing that -needs to be public.""" - -[[exercises]] -name = "modules2" -path = "exercises/modules/modules2.rs" -mode = "compile" -hint = """ -The delicious_snacks module is trying to present an external -interface (the `fruit` and `veggie` constants) that is different than -its internal structure (the `fruits` and `veggies` modules and -associated constants). It's almost there except for one keyword missing for -each constant.""" - -# COLLECTIONS - -[[exercises]] -name = "collections1" -path = "exercises/collections/vec1.rs" -mode = "test" -hint = """ -In Rust, there are two ways to define a Vector. - -1. One way is to use the `Vec::new()` function to create a new vector - and fill it with the `push()` method. - -2. The second way, which is simpler is to use the `vec![]` macro and - define your elements inside the square brackets. - -Check this chapter: https://doc.rust-lang.org/stable/book/ch08-01-vectors.html -of the Rust book to learn more. -""" - -[[exercises]] -name = "collections2" -path = "exercises/collections/vec2.rs" -mode = "test" -hint = """ -Hint 1: `i` is each element from the Vec as they are being iterated. - Can you try multiplying this? - -Hint 2: Check the suggestion from the compiler error ;) -""" - -[[exercises]] -name = "collections3" -path = "exercises/collections/hashmap1.rs" -mode = "test" -hint = """ -Hint 1: Take a look at the return type of the function to figure out - the type for the `basket`. - -Hint 2: Number of fruits should be at least 5. And you have to put - at least three different types of fruits. -""" - -[[exercises]] -name = "collections4" -path = "exercises/collections/hashmap2.rs" -mode = "test" -hint = """ -Use the `entry()` and `or_insert()` methods of `HashMap` to achieve this. - -Learn more at https://doc.rust-lang.org/stable/book/ch08-03-hash-maps.html#only-inserting-a-value-if-the-key-has-no-value -""" - -# MACROS - -[[exercises]] -name = "macros1" -path = "exercises/macros/macros1.rs" -mode = "compile" -hint = """ -When you call a macro, you need to add something special compared to a -regular function call. If you're stuck, take a look at what's inside -`my_macro`.""" - -[[exercises]] -name = "macros2" -path = "exercises/macros/macros2.rs" -mode = "compile" -hint = """ -Macros don't quite play by the same rules as the rest of Rust, in terms of -what's available where. - -Unlike other things in Rust, the order of "where you define a macro" versus -"where you use it" actually matters.""" - -[[exercises]] -name = "macros3" -path = "exercises/macros/macros3.rs" -mode = "compile" -hint = """ -In order to use a macro outside of its module, you need to do something -special to the module to lift the macro out into its parent. - -The same trick also works on "extern crate" statements for crates that have -exported macros, if you've seen any of those around.""" - -[[exercises]] -name = "macros4" -path = "exercises/macros/macros4.rs" -mode = "compile" -hint = """ -You only need to add a single character to make this compile. -The way macros are written, it wants to see something between each -"macro arm", so it can separate them.""" -# TEST 4 - -[[exercises]] -name = "quiz4" -path = "exercises/quiz4.rs" -mode = "test" -hint = "No hints this time ;)" - -# MOVE SEMANTICS - -[[exercises]] -name = "move_semantics1" -path = "exercises/move_semantics/move_semantics1.rs" -mode = "compile" -hint = """ -So you've got the "cannot borrow immutable local variable `vec1` as mutable" error on line 13, -right? The fix for this is going to be adding one keyword, and the addition is NOT on line 13 -where the error is.""" - -[[exercises]] -name = "move_semantics2" -path = "exercises/move_semantics/move_semantics2.rs" -mode = "compile" -hint = """ -So `vec0` is being *moved* into the function `fill_vec` when we call it on -line 10, which means it gets dropped at the end of `fill_vec`, which means we -can't use `vec0` again on line 13 (or anywhere else in `main` after the -`fill_vec` call for that matter). We could fix this in a few ways, try them -all! -1. Make another, separate version of the data that's in `vec0` and pass that - to `fill_vec` instead. -2. Make `fill_vec` borrow its argument instead of taking ownership of it, - and then copy the data within the function in order to return an owned - `Vec` -3. Make `fill_vec` *mutably* borrow its argument (which will need to be - mutable), modify it directly, then not return anything. Then you can get rid - of `vec1` entirely -- note that this will change what gets printed by the - first `println!`""" - -[[exercises]] -name = "move_semantics3" -path = "exercises/move_semantics/move_semantics3.rs" -mode = "compile" -hint = """ -The difference between this one and the previous ones is that the first line -of `fn fill_vec` that had `let mut vec = vec;` is no longer there. You can, -instead of adding that line back, add `mut` in one place that will change -an existing binding to be a mutable binding instead of an immutable one :)""" - -[[exercises]] -name = "move_semantics4" -path = "exercises/move_semantics/move_semantics4.rs" -mode = "compile" -hint = """ -Stop reading whenever you feel like you have enough direction :) Or try -doing one step and then fixing the compiler errors that result! -So the end goal is to: - - get rid of the first line in main that creates the new vector - - so then `vec0` doesn't exist, so we can't pass it to `fill_vec` - - we don't want to pass anything to `fill_vec`, so its signature should - reflect that it does not take any arguments - - 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`""" - # ERROR HANDLING [[exercises]] @@ -607,6 +466,40 @@ 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""" +# Generics + +[[exercises]] +name = "generics1" +path = "exercises/generics/generics1.rs" +mode = "compile" +hint = """ +Vectors in rust make use of generics to create dynamically sized arrays of any type. +You need to tell the compiler what type we are pushing onto this vector.""" + +[[exercises]] +name = "generics2" +path = "exercises/generics/generics2.rs" +mode = "test" +hint = """ +Currently we are wrapping only values of type 'u32'. +Maybe we could update the explicit references to this data type somehow? + +If you are still stuck https://doc.rust-lang.org/stable/book/ch10-01-syntax.html#in-method-definitions +""" + +[[exercises]] +name = "generics3" +path = "exercises/generics/generics3.rs" +mode = "test" +hint = """ +To find the best solution to this challenge you're going to need to think back to your +knowledge of traits, specifically Trait Bound Syntax - you may also need this: "use std::fmt::Display;" + +This is definitely harder than the last two exercises! You need to think about not only making the +ReportCard struct generic, but also the correct property - you will need to change the implementation +of the struct slightly too...you can do it! +""" + # OPTIONS / RESULTS [[exercises]] @@ -649,21 +542,67 @@ hint = """ 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 :)""" -# CLIPPY +# TRAITS [[exercises]] -name = "clippy1" -path = "exercises/clippy/clippy1.rs" -mode = "clippy" +name = "traits1" +path = "exercises/traits/traits1.rs" +mode = "test" hint = """ -Floating point calculations are usually imprecise, so asking if two values are exactly equal is asking for trouble""" +A discussion about Traits in Rust can be found at: +https://doc.rust-lang.org/book/ch10-02-traits.html +""" [[exercises]] -name = "clippy2" -path = "exercises/clippy/clippy2.rs" -mode = "clippy" +name = "traits2" +path = "exercises/traits/traits2.rs" +mode = "test" hint = """ -`for` loops over Option values are more clearly expressed as an `if let`""" +Notice how the trait takes ownership of 'self',and returns `Self'. +Try mutating the incoming string vector. + +Vectors provide suitable methods for adding an element at the end. See +the documentation at: https://doc.rust-lang.org/std/vec/struct.Vec.html""" + +# TESTS + +[[exercises]] +name = "tests1" +path = "exercises/tests/tests1.rs" +mode = "test" +hint = """ +You don't even need to write any code to test -- you can just test values and run that, even +though you wouldn't do that in real life :) `assert!` is a macro that needs an argument. +Depending on the value of the argument, `assert!` will do nothing (in which case the test will +pass) or `assert!` will panic (in which case the test will fail). So try giving different values +to `assert!` and see which ones compile, which ones pass, and which ones fail :)""" + +[[exercises]] +name = "tests2" +path = "exercises/tests/tests2.rs" +mode = "test" +hint = """ +Like the previous exercise, you don't need to write any code to get this test to compile and +run. `assert_eq!` is a macro that takes two arguments and compares them. Try giving it two +values that are equal! Try giving it two arguments that are different! Try giving it two values +that are of different types! Try switching which argument comes first and which comes second!""" + +[[exercises]] +name = "tests3" +path = "exercises/tests/tests3.rs" +mode = "test" +hint = """ +You can call a function right where you're passing arguments to `assert!` -- so you could do +something like `assert!(having_fun())`. If you want to check that you indeed get false, you +can negate the result of what you're doing using `!`, like `assert!(!having_fun())`.""" + +# TEST 3 + +[[exercises]] +name = "quiz3" +path = "exercises/quiz3.rs" +mode = "test" +hint = "No hints this time ;)" # STANDARD LIBRARY TYPES @@ -697,27 +636,6 @@ inside the loop but still in the main thread. `child_numbers` should be a clone of the Arc of the numbers instead of a thread-local copy of the numbers.""" -[[exercises]] -name = "iterators1" -path = "exercises/standard_library_types/iterators1.rs" -mode = "compile" -hint = """ -Step 1: -We need to apply something to the collection `my_fav_fruits` before we start to go through -it. What could that be? Take a look at the struct definition for a vector for inspiration: -https://doc.rust-lang.org/std/vec/struct.Vec.html. - - -Step 2 & step 2.1: -Very similar to the lines above and below. You've got this! - - -Step 3: -An iterator goes through all elements in a collection, but what if we've run out of -elements? What should we expect here? If you're stuck, take a look at -https://doc.rust-lang.org/std/iter/trait.Iterator.html for some ideas. -""" - [[exercises]] name = "iterators2" path = "exercises/standard_library_types/iterators2.rs" @@ -761,62 +679,6 @@ a mutable variable. Or, you might write code utilizing recursion and a match clause. In Rust you can take another functional approach, computing the factorial elegantly with ranges and iterators.""" -# TRAITS - -[[exercises]] -name = "traits1" -path = "exercises/traits/traits1.rs" -mode = "test" -hint = """ -A discussion about Traits in Rust can be found at: -https://doc.rust-lang.org/book/ch10-02-traits.html -""" - -[[exercises]] -name = "traits2" -path = "exercises/traits/traits2.rs" -mode = "test" -hint = """ -Notice how the trait takes ownership of 'self',and returns `Self'. -Try mutating the incoming string vector. - -Vectors provide suitable methods for adding an element at the end. See -the documentation at: https://doc.rust-lang.org/std/vec/struct.Vec.html""" - -# Generics - -[[exercises]] -name = "generics1" -path = "exercises/generics/generics1.rs" -mode = "compile" -hint = """ -Vectors in rust make use of generics to create dynamically sized arrays of any type. -You need to tell the compiler what type we are pushing onto this vector.""" - -[[exercises]] -name = "generics2" -path = "exercises/generics/generics2.rs" -mode = "test" -hint = """ -Currently we are wrapping only values of type 'u32'. -Maybe we could update the explicit references to this data type somehow? - -If you are still stuck https://doc.rust-lang.org/stable/book/ch10-01-syntax.html#in-method-definitions -""" - -[[exercises]] -name = "generics3" -path = "exercises/generics/generics3.rs" -mode = "test" -hint = """ -To find the best solution to this challenge you're going to need to think back to your -knowledge of traits, specifically Trait Bound Syntax - you may also need this: "use std::fmt::Display;" - -This is definitely harder than the last two exercises! You need to think about not only making the -ReportCard struct generic, but also the correct property - you will need to change the implementation -of the struct slightly too...you can do it! -""" - # THREADS [[exercises]] @@ -856,6 +718,72 @@ If you've learned from the sample solutions, I encourage you to come back to this exercise and try it again in a few days to reinforce what you've learned :)""" +# MACROS + +[[exercises]] +name = "macros1" +path = "exercises/macros/macros1.rs" +mode = "compile" +hint = """ +When you call a macro, you need to add something special compared to a +regular function call. If you're stuck, take a look at what's inside +`my_macro`.""" + +[[exercises]] +name = "macros2" +path = "exercises/macros/macros2.rs" +mode = "compile" +hint = """ +Macros don't quite play by the same rules as the rest of Rust, in terms of +what's available where. + +Unlike other things in Rust, the order of "where you define a macro" versus +"where you use it" actually matters.""" + +[[exercises]] +name = "macros3" +path = "exercises/macros/macros3.rs" +mode = "compile" +hint = """ +In order to use a macro outside of its module, you need to do something +special to the module to lift the macro out into its parent. + +The same trick also works on "extern crate" statements for crates that have +exported macros, if you've seen any of those around.""" + +[[exercises]] +name = "macros4" +path = "exercises/macros/macros4.rs" +mode = "compile" +hint = """ +You only need to add a single character to make this compile. +The way macros are written, it wants to see something between each +"macro arm", so it can separate them.""" + +# TEST 4 + +[[exercises]] +name = "quiz4" +path = "exercises/quiz4.rs" +mode = "test" +hint = "No hints this time ;)" + +# CLIPPY + +[[exercises]] +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""" + +[[exercises]] +name = "clippy2" +path = "exercises/clippy/clippy2.rs" +mode = "clippy" +hint = """ +`for` loops over Option values are more clearly expressed as an `if let`""" + # TYPE CONVERSIONS [[exercises]]