//@ 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`!
+//@ So we can just write `i * i`, the expression that returns the square of `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
+// Conditionals are also just expressions. This is comparable to the ternary `? :` operator
// from languages like C.
fn abs(i: i32) -> i32 { if i >= 0 { i } else { -i } }
}
}
+// It is even the case that blocks are expressions, evaluating to the last expression they contain.
+fn compute_stuff(x: i32) -> i32 {
+ let y = { let z = x*x; z + 14 };
+ y*y
+}
+
// 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
+ //@ significantly increase readability.
fn min_i32(a: i32, b: i32) -> i32 {
if a < b { a } else { b } /*@*/
}
// You will have to replace `part00` by `part01` in the `main` function in
// `main.rs` to run this code.
-// **Exercise 01.1**: Write a funtion `vec_sum` that computes the sum of all values of a `Vec<i32>`.
+// **Exercise 01.1**: Write a function `vec_sum` that computes the sum of all values of a `Vec<i32>`.
// **Exercise 01.2**: Write a function `vec_print` that takes a vector and prints all its elements.
-//@ [index](main.html) | [previous](part00.html) | [next](part02.html)
+//@ [index](main.html) | [previous](part00.html) | [raw source](workspace/src/part01.rs) |
+//@ [next](part02.html)