X-Git-Url: https://git.ralfj.de/rust-101.git/blobdiff_plain/4f61be32dd480f23a7fef05ee66c42ae27c980c6..04e6bfa1aab433e4cfb0058132f7b57258ddcd16:/src/part01.rs

diff --git a/src/part01.rs b/src/part01.rs
index ed4f73f..e00cf53 100644
--- a/src/part01.rs
+++ b/src/part01.rs
@@ -13,10 +13,10 @@
 //@ 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 } }
 
@@ -35,11 +35,18 @@ fn number_or_default(n: NumberOrNothing, default: i32) -> i32 {
     }
 }
 
+// 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 }                                   /*@*/
     }
@@ -80,7 +87,7 @@ impl NumberOrNothing {
 //@ 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`.
+//@ takes `NumberOrNothing` as the first argument, just like `print_number_or_nothing`.
 //@ 
 //@ Try making `number_or_default` from above an inherent method as well!
 
@@ -96,8 +103,9 @@ pub fn main() {
 // 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)