X-Git-Url: https://git.ralfj.de/rust-101.git/blobdiff_plain/b60c82e9d3b03aa36484c1ff68f34f4e78862d46..10d94a73ebbb793c1792886bdedd13799296e847:/src/part03.rs?ds=sidebyside diff --git a/src/part03.rs b/src/part03.rs index ef8ab92..81f8714 100644 --- a/src/part03.rs +++ b/src/part03.rs @@ -6,7 +6,7 @@ //@ I/O is a complicated topic, so the code to do that is not exactly pretty - but well, //@ let's get that behind us. -// I/O is provided by the module `std::io`, so we first have import that with `use`. +// I/O is provided by the module `std::io`, so we first have to import that with `use`. // We also import the I/O *prelude*, which makes a bunch of commonly used I/O stuff // directly available. use std::io::prelude::*; @@ -24,19 +24,19 @@ fn read_vec() -> Vec { let mut vec: Vec = Vec::::new(); // The central handle to the standard input is made available by the function `io::stdin`. let stdin = io::stdin(); - println!("Enter a list of numbers, one per line. End with Ctrl-D."); + println!("Enter a list of numbers, one per line. End with Ctrl-D (Linux) or Ctrl-Z (Windows)."); //@ We would now like to iterate over standard input line-by-line. We can use a `for` loop //@ for that, but there is a catch: What happens if there is some other piece of code running //@ concurrently, that also reads from standard input? The result would be a mess. Hence //@ Rust requires us to `lock` standard input if we want to perform large operations on - //@ it. (See [the documentation](http://doc.rust-lang.org/stable/std/io/struct.Stdin.html) for more + //@ it. (See [the documentation](https://doc.rust-lang.org/stable/std/io/struct.Stdin.html) for more //@ details.) for line in stdin.lock().lines() { // Rust's type for (dynamic, growable) strings is `String`. However, our variable `line` // here is not yet of that type: It has type `io::Result`. //@ The problem with I/O is that it can always go wrong. The type of `line` is a lot like `Option` ("a `String` or //@ nothing"), but in the case of "nothing", there is additional information about the error. - //@ Again, I recommend to check [the documentation](http://doc.rust-lang.org/stable/std/io/type.Result.html). + //@ Again, I recommend to check [the documentation](https://doc.rust-lang.org/stable/std/io/type.Result.html). //@ You will see that `io::Result` is actually just an alias for `Result`, so click on that to obtain //@ the list of all constructors and methods of the type. @@ -51,7 +51,7 @@ fn read_vec() -> Vec { let line = line.unwrap(); // Now that we have our `String`, we want to make it an `i32`. //@ We first `trim` the `line` to remove leading and trailing whitespace. - //@ `parse` is a method on `String` that can convert a string to anything. Try finding it's documentation! + //@ `parse` is a method on `String` that can convert a string to anything. Try finding its documentation! //@ In this case, Rust *could* figure out automatically that we need an `i32` (because of the return type //@ of the function), but that's a bit too much magic for my taste. We are being more explicit here: @@ -104,7 +104,7 @@ pub fn main() { // Notice that I called the function on `SomethingOrNothing` `print2` to disambiguate from the `print` defined previously. // // *Hint*: There is a macro `print!` for printing without appending a newline. -trait Print { +pub trait Print { /* Add things here */ } impl SomethingOrNothing { @@ -116,4 +116,4 @@ impl SomethingOrNothing { // **Exercise 03.2**: Building on exercise 02.2, implement all the things you need on `f32` to make your // program work with floating-point numbers. -//@ [index](main.html) | [previous](part02.html) | [next](part04.html) +//@ [index](main.html) | [previous](part02.html) | [raw source](workspace/src/part03.rs) | [next](part04.html)