write code for part 03

diff --git a/src/main.rs b/src/main.rs
index b635f7ebe80be403eafabe0eafc0dfe18a95b358..e89f2f145aa4aee757c3c2ce191c7468e3e3eb10 100644 (file)
--- a/src/main.rs
+++ b/src/main.rs
@@ -41,11 +41,13 @@
 // * [Part 00](part00.html)
 // * [Part 01](part01.html)
 // * [Part 02](part02.html)
+// * [Part 03](part03.html) (WIP)
 // * (to be continued)
 #![allow(dead_code, unused_imports, unused_variables)]
 mod part00;
 mod part01;
 mod part02;
+mod part03;
 
 // To actually run the code of some part (after filling in the blanks, if necessary), simply edit the `main`
 // function.

diff --git a/src/part02.rs b/src/part02.rs
index a9f9b0576988899c279873bb4f7671e3bb574894..7261f1900ac989b8a920367e5ebbc32b84420f7d 100644 (file)
--- a/src/part02.rs
+++ b/src/part02.rs
@@ -155,4 +155,4 @@ impl<T: Print> SomethingOrNothing<T> {
     }
 }
 
-// [index](main.html) | [previous](part01.html) | next
+// [index](main.html) | [previous](part01.html) | [next](part03.html)

diff --git a/src/part03.rs b/src/part03.rs
new file mode 100644 (file)
index 0000000..cb0807b
--- /dev/null
+++ b/src/part03.rs
@@ -0,0 +1,67 @@
+// Rust-101, Part 03: Input, Formatting
+// ====================================
+
+use std::io::prelude::*;
+use std::io;
+
+fn read_vec() -> Vec<i32> {
+    let mut vec = Vec::new();
+
+    let stdin = io::stdin();
+    println!("Enter a list of numbers, one per line. End with Ctrl-D.");
+    for line in stdin.lock().lines() {
+        let line = line.unwrap();
+        match line.parse::<i32>() {
+            Ok(num) => vec.push(num),
+            Err(_) => println!("What did I say about numbers?"),
+        }
+    }
+
+    vec
+}
+
+enum SomethingOrNothing<T>  {
+    Something(T),
+    Nothing,
+}
+use self::SomethingOrNothing::{Something,Nothing};
+
+trait Minimum : Copy {
+    fn min(a: Self, b: Self) -> Self;
+}
+
+fn vec_min<T: Minimum>(v: &Vec<T>) -> SomethingOrNothing<T> {
+    let mut min = Nothing;
+    for e in v {
+        let e = *e;
+        min = Something(match min {
+            Nothing => e,
+            Something(n) => T::min(n, e)
+        });
+    }
+    min
+}
+
+impl Minimum for i32 {
+    fn min(a: Self, b: Self) -> Self {
+        ::std::cmp::min(a, b)
+    }
+}
+
+use std::fmt;
+impl<T: fmt::Display> fmt::Display for SomethingOrNothing<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            &Something(ref t) => t.fmt(f),
+            &Nothing => "Nothing".fmt(f),
+        }
+    }
+}
+
+pub fn part_main() {
+    let vec = read_vec();
+    let min = vec_min(&vec);
+    println!("The minimum is: {}", min);
+}
+
+// [index](main.html) | [previous](part02.html) | next