// tutorial for the [Rust language](http://www.rust-lang.org/).
// It is intended to be an interactive, hands-on course: I believe the only way to
// *really* learn a language is to write code in it, so you should be coding during
-// the course. I am writing this with a tutorial situation in mind, i.e.,
-// with a teacher being around to guide students through the course and answer
-// questions as they come up. However, I think they may also be useful if you
-// work through them on your own, you will just have to show more initiative yourself:
-// Make sure you actually type some code. It may sound stupid to manually copy code
-// that you could duplicate through the clipboard, but it's actually helpful.
-// If you have questions, check out the "Additional Resources" below. In particular,
-// the IRC channel is filled with awesome people willing to help you! I spent
+// the course.
+//
+// If you have any questions that are not answered here, check out the "Additional Resources"
+// below. In particular, the IRC channel is filled with awesome people willing to help you! I spent
// lots of time there ;-)
//
// I will assume some familiarity with programming, and hence not explain the basic
// cost. This is combined with the comfort of high-level functional languages and guaranteed
// safety (as in, the program will not crash). The vast majority of existing
// languages sacrificies one of these goals for the other. In particular, the
-// first requirement rules out a garbage collector: Rust can run "mare metal".
+// first requirement rules out a garbage collector: Rust can run "bare metal".
// In fact, Rust rules out more classes of bugs than languages that achieve safety
// with a GC: Besides dangling pointers and double-free, Rust also prevents issues
// such as iterator invalidation and race conditions.
// [the Rust website](http://www.rust-lang.org/). You should go for either the "stable"
// or the "beta" channel. More detailed installation instructions are provided in
// [the second chapter of The Book](https://doc.rust-lang.org/stable/book/installing-rust.html).
+// This will also install `cargo`, the tool responsible for building rust projects (or *crates*).
// Next, fetch the Rust-101 source code from the [git repository](http://www.ralfj.de/git/rust-101.git)
-// (also available [on GitHub](https://github.com/RalfJung/rust-101)).
-// To generate your workspace, run `make workspace` (this needs GNU sed). I suggest you now copy the
-// `workspace` folder somewhere else - that will make it much easier to later update the course without
+// (also available [on GitHub](https://github.com/RalfJung/rust-101), and as [zip archive](https://github.com/RalfJung/rust-101/archive/master.zip)).
+// There is a workspace prepared for you in the `workspace` folder. I suggest you copy this
+// folder somewhere else - that will make it much easier to later update the course without
// overwriting your changes. Try `cargo build` in that new folder to check that compiling your workspace succeeds.
// (You can also execute it with `cargo run`, but you'll need to do some work before this will succeed.)
//
-// If you later want to update the course, do `git pull` followed by `make workspace`. Then copy the files
-// from `workspace/src/` to your workspace that you did not yet work on. (Of course you can also copy the rest,
-// but that would replace all your hard work by the original files with all the holes!)
+// If you later want to update the course, do `git pull` (or re-download the tip archive).
+// Then copy the files from `workspace/src/` to your workspace that you did not yet work on. (Of course you can also
+// copy the rest, but that would replace all your hard work by the original files with all the holes!)
// Course Content
// --------------
// mechanisms like pattern matching and traits. Parts 04-06 introduce the heart of the language, the ideas
// making it different from anything else out there: Ownership, borrowing, lifetimes. In part 07-??, we
// continue our tour through Rust with another example. Finally, in parts ??-??, we implement our own
-// version of `grep`, exhibiting useful Rust features as we go.
+// version of `grep`, exhibiting some more Rust features as we go.
//
// Now, open `your-workspace/src/part00.rs` in your favorite editor, and follow the link below for
// the explanations and exercises. Have fun!
NumberOrNothing::Nothing => {
min = NumberOrNothing::Number(el); /*@*/
},
- // In this arm, `min` is currently the number `n`, so let's compute the new minimum and store it. We will write
- // the function `min_i32` just after we completed this one.
+ // In this arm, `min` is currently the number `n`, so let's compute the new minimum and store it.
+ //@ We will write the function `min_i32` just after we completed this one.
NumberOrNothing::Number(n) => {
let new_min = min_i32(n, el); /*@*/
min = NumberOrNothing::Number(new_min); /*@*/
// To call this function, we now just need a list. Of course, ultimately we want to ask the user for
// a list of numbers, but for now, let's just hard-code something.
-// `vec!` is a *macro* (as you can tell from the `!`) that constructs a constant `Vec<_>` with the given
-// elements.
+//@ `vec!` is a *macro* (as you can tell from the `!`) that constructs a constant `Vec<_>` with the given
+//@ elements.
fn read_vec() -> Vec<i32> {
- vec![18,5,7,1,9,27]
+ vec![18,5,7,1,9,27] /*@*/
}
// Finally, let's call our functions and run the code!
//@ now, you just need to know that `{}` is the placeholder for a value, and that Rust
//@ will check at compile-time that you supplied the right number of arguments.
fn print_number_or_nothing(n: NumberOrNothing) {
- match n {
- Nothing => println!("The number is: <nothing>"),
- Number(n) => println!("The number is: {}", n),
- };
+ match n { /*@*/
+ Nothing => println!("The number is: <nothing>"), /*@*/
+ Number(n) => println!("The number is: {}", n), /*@*/
+ }; /*@*/
}
// Putting it all together:
print_number_or_nothing(min);
}
-// Now try `cargo run` on the console to run above code.
+// You can now use `cargo build` to compile your code. If all goes well, try `cargo run` on the
+// console to run it.
//@ Yay, it said "1"! That's actually the right answer. Okay, we could have
//@ computed that ourselves, but that's besides the point. More importantly:
//@ You completed the first part of the course.
-// [index](main.html) | previous | [next](part01.html)
+//@ [index](main.html) | previous | [next](part01.html)
// Rust-101, Part 01: Expressions, Inherent methods
// ================================================
-// Even though our code from the first part works, we can still learn a
-// lot by making it prettier. To understand how, it is important to
-// understand that Rust is an "expression-based" language. This means that most of the
-// terms you write down are not just *statements* (executing code), but *expressions*
-// (returning a value). This applies even to the body of entire functions!
+// For Rust to compile this file, make sure to enable the corresponding line
+// in `main.rs` before going on.
+
+//@ Even though our code from the first part works, we can still learn a
+//@ lot by making it prettier. That's because Rust is an "expression-based" language, which
+//@ means that most of the terms you write down are not just *statements* (executing code), but
+//@ *expressions* (returning a value). This applies even to the body of entire functions!
// ## Expression-based programming
-// For example, consider `sqr`:
+//@ For example, consider `sqr`:
fn sqr(i: i32) -> i32 { i * i }
-// Between the curly braces, we are giving the *expression* that computes the return value.
-// So we can just write `i * i`, the expression that returns the square if `i`!
-// This is very close to how mathematicians write down functions (but with more types).
+//@ Between the curly braces, we are giving the *expression* that computes the return value.
+//@ So we can just write `i * i`, the expression that returns the square if `i`!
+//@ This is very close to how mathematicians write down functions (but with more types).
// Conditionals are also just expressions. You can compare this to the ternary `? :` operator
// from languages like C.
fn abs(i: i32) -> i32 { if i >= 0 { i } else { -i } }
-// And the same applies to case distinction with `match`: Every `arm` of the match
-// gives the expression that is returned in the respective case.
-// (We repeat the definition from the previous part here.)
+//@ And the same applies to case distinction with `match`: Every `arm` of the match
+//@ gives the expression that is returned in the respective case.
+//@ (We repeat the definition from the previous part here.)
enum NumberOrNothing {
Number(i32),
Nothing
// Let us now refactor `vec_min`.
fn vec_min(v: Vec<i32>) -> NumberOrNothing {
- // Remember that helper function `min_i32`? Rust allows us to define such helper functions *inside* other
- // functions. This is just a matter of namespacing, the inner function has no access to the data of the outer
- // one. Still, being able to nicely group functions can be very useful.
+ //@ Remember that helper function `min_i32`? Rust allows us to define such helper functions *inside* other
+ //@ functions. This is just a matter of namespacing, the inner function has no access to the data of the outer
+ //@ one. Still, being able to nicely group functions can be very useful.
fn min_i32(a: i32, b: i32) -> i32 {
- if a < b { a } else { b }
+ if a < b { a } else { b } /*@*/
}
let mut min = Nothing;
for e in v {
- // Notice that all we do here is compute a new value for `min`, and that it will always end
- // up being a `Number` rather than `Nothing`. In Rust, the structure of the code
- // can express this uniformity.
- min = Number(match min {
- Nothing => e,
- Number(n) => min_i32(n, e)
- });
+ //@ Notice that all we do here is compute a new value for `min`, and that it will always end
+ //@ up being a `Number` rather than `Nothing`. In Rust, the structure of the code
+ //@ can express this uniformity.
+ min = Number(match min { /*@*/
+ Nothing => e, /*@*/
+ Number(n) => min_i32(n, e) /*@*/
+ }); /*@*/
}
- // The `return` keyword exists in Rust, but it is rarely used. Instead, we typically
- // make use of the fact that the entire function body is an expression, so we can just
- // write down the desired return value.
+ //@ The `return` keyword exists in Rust, but it is rarely used. Instead, we typically
+ //@ make use of the fact that the entire function body is an expression, so we can just
+ //@ write down the desired return value.
min
}
// every step of what's going on.
// ## Inherent implementations
-// So much for `vec_min`. Let us now reconsider `print_number_or_nothing`. That function
-// really belongs pretty close to the type `NumberOrNothing`. In C++ or Java, you would
-// probably make it a method of the type. In Rust, we can achieve something very similar
-// by providing an *inherent implementation*.
+//@ So much for `vec_min`. Let us now reconsider `print_number_or_nothing`. That function
+//@ really belongs pretty close to the type `NumberOrNothing`. In C++ or Java, you would
+//@ probably make it a method of the type. In Rust, we can achieve something very similar
+//@ by providing an *inherent implementation*.
impl NumberOrNothing {
fn print(self) {
match self {
};
}
}
-// So, what just happened? Rust separates code from data, so the definition of the
-// methods on an `enum` (and also on `struct`, which we will learn about later)
-// is independent of the definition of the type. `self` is like `this` in other
-// languages, and its type is always implicit. So `print` is now a method that
-// takes as first argument a `NumberOrNothing`, just like `print_number_or_nothing`.
-//
-// Try making `number_or_default` from above an inherent method as well!
+//@ So, what just happened? Rust separates code from data, so the definition of the
+//@ methods on an `enum` (and also on `struct`, which we will learn about later)
+//@ is independent of the definition of the type. `self` is like `this` in other
+//@ languages, and its type is always implicit. So `print` is now a method that
+//@ takes as first argument a `NumberOrNothing`, just like `print_number_or_nothing`.
+//@
+//@ Try making `number_or_default` from above an inherent method as well!
// With our refactored functions and methods, `main` now looks as follows:
fn read_vec() -> Vec<i32> {
pub fn main() {
let vec = read_vec();
let min = vec_min(vec);
- min.print();
+ min.print(); /*@*/
}
// You will have to replace `part00` by `part01` in the `main` function in
// `main.rs` to run this code.
NumberOrNothing::Nothing => {
unimplemented!()
},
- // In this arm, `min` is currently the number `n`, so let's compute the new minimum and store it. We will write
- // the function `min_i32` just after we completed this one.
+ // In this arm, `min` is currently the number `n`, so let's compute the new minimum and store it.
NumberOrNothing::Number(n) => {
unimplemented!()
}
// To call this function, we now just need a list. Of course, ultimately we want to ask the user for
// a list of numbers, but for now, let's just hard-code something.
-// `vec!` is a *macro* (as you can tell from the `!`) that constructs a constant `Vec<_>` with the given
-// elements.
fn read_vec() -> Vec<i32> {
- vec![18,5,7,1,9,27]
+ unimplemented!()
}
// Finally, let's call our functions and run the code!
// So let's write a small helper function that prints such values.
fn print_number_or_nothing(n: NumberOrNothing) {
- match n {
- Nothing => println!("The number is: <nothing>"),
- Number(n) => println!("The number is: {}", n),
- };
+ unimplemented!()
}
// Putting it all together:
print_number_or_nothing(min);
}
-// Now try `cargo run` on the console to run above code.
+// You can now use `cargo build` to compile your code. If all goes well, try `cargo run` on the
+// console to run it.
-// [index](main.html) | previous | [next](part01.html)
// Rust-101, Part 01: Expressions, Inherent methods
// ================================================
-// Even though our code from the first part works, we can still learn a
-// lot by making it prettier. To understand how, it is important to
-// understand that Rust is an "expression-based" language. This means that most of the
-// terms you write down are not just *statements* (executing code), but *expressions*
-// (returning a value). This applies even to the body of entire functions!
+// For Rust to compile this file, make sure to enable the corresponding line
+// in `main.rs` before going on.
+
// ## Expression-based programming
-// For example, consider `sqr`:
fn sqr(i: i32) -> i32 { i * i }
-// Between the curly braces, we are giving the *expression* that computes the return value.
-// So we can just write `i * i`, the expression that returns the square if `i`!
-// This is very close to how mathematicians write down functions (but with more types).
// Conditionals are also just expressions. You can compare this to the ternary `? :` operator
// from languages like C.
fn abs(i: i32) -> i32 { if i >= 0 { i } else { -i } }
-// And the same applies to case distinction with `match`: Every `arm` of the match
-// gives the expression that is returned in the respective case.
-// (We repeat the definition from the previous part here.)
enum NumberOrNothing {
Number(i32),
Nothing
// Let us now refactor `vec_min`.
fn vec_min(v: Vec<i32>) -> NumberOrNothing {
- // Remember that helper function `min_i32`? Rust allows us to define such helper functions *inside* other
- // functions. This is just a matter of namespacing, the inner function has no access to the data of the outer
- // one. Still, being able to nicely group functions can be very useful.
fn min_i32(a: i32, b: i32) -> i32 {
- if a < b { a } else { b }
+ unimplemented!()
}
let mut min = Nothing;
for e in v {
- // Notice that all we do here is compute a new value for `min`, and that it will always end
- // up being a `Number` rather than `Nothing`. In Rust, the structure of the code
- // can express this uniformity.
- min = Number(match min {
- Nothing => e,
- Number(n) => min_i32(n, e)
- });
+ unimplemented!()
}
- // The `return` keyword exists in Rust, but it is rarely used. Instead, we typically
- // make use of the fact that the entire function body is an expression, so we can just
- // write down the desired return value.
min
}
// every step of what's going on.
// ## Inherent implementations
-// So much for `vec_min`. Let us now reconsider `print_number_or_nothing`. That function
-// really belongs pretty close to the type `NumberOrNothing`. In C++ or Java, you would
-// probably make it a method of the type. In Rust, we can achieve something very similar
-// by providing an *inherent implementation*.
impl NumberOrNothing {
fn print(self) {
match self {
};
}
}
-// So, what just happened? Rust separates code from data, so the definition of the
-// methods on an `enum` (and also on `struct`, which we will learn about later)
-// is independent of the definition of the type. `self` is like `this` in other
-// languages, and its type is always implicit. So `print` is now a method that
-// takes as first argument a `NumberOrNothing`, just like `print_number_or_nothing`.
-//
-// Try making `number_or_default` from above an inherent method as well!
// With our refactored functions and methods, `main` now looks as follows:
fn read_vec() -> Vec<i32> {
pub fn main() {
let vec = read_vec();
let min = vec_min(vec);
- min.print();
+ unimplemented!()
}
// You will have to replace `part00` by `part01` in the `main` function in
// `main.rs` to run this code.
projects / rust-101.git / commitdiff