readme

README.md

@@ -0,0 +1 @@
+simple implementation of linkedlist for rust workshop, with tags on every commit

src/main.rs

@@ -1,34 +1,56 @@
-fn main() {}
-
-#[derive(Debug)]
-pub struct List {
-    head: Link,
+fn main() {
+    let mut list = List::new();
+    list.push(1);
+    println!("push(1) : {:?}", list);
+    list.push(2);
+    println!("push(2) : {:?}", list);
+    println!("pop() -> {} : {:?}", list.pop().unwrap(), list);
+    println!("pop() -> {} : {:?}", list.pop().unwrap(), list);
 }
 
 #[derive(Debug)]
-enum Link {
-    Empty,
-    More(Box<Node>),
+pub struct List<T> {
+    head: Link<T>,
 }
 
+type Link<T> = Option<Box<Node<T>>>;
+
 #[derive(Debug)]
-struct Node {
-    elem: i32,
-    next: Link,
+struct Node<T> {
+    elem: T,
+    next: Link<T>,
 }
 
-impl List {
+impl<T> List<T> {
     pub fn new() -> Self {
-        Self { head: Link::Empty }
+        Self { head: None }
     }
 
-    pub fn push(&mut self, elem: i32) {
+    pub fn push(&mut self, elem: T) {
         let new_node = Node {
             elem: elem,
-            next: std::mem::replace(&mut self.head, Link::Empty),
+            next: self.head.take(),
         };
-        self.head = Link::More(Box::new(new_node));
+        self.head = Some(Box::new(new_node));
+    }
+
+    pub fn pop(&mut self) -> Option<T> {
+        self.head.take().map(|node| {
+            self.head = node.next;
+            node.elem
+        })
     }
 }
 
+#[cfg(test)]
+mod tests {
 
+    use super::*;
+
+    #[test]
+    fn test() {
+        let mut list = List::new();
+        list.push(42);
+        assert_eq!(Some(42), list.pop());
+    }
+}