14 /// Implementation of a `Stack` which maintains an log of `StackOp`s in order to rewind the stack
17 pub struct Stack<T: Clone> {  struct
23 impl<T: Clone> Stack<T> {  argument
24     /// Creates a new `Stack`.
26         Stack {  in new()
33     /// Returns `true` if the stack is currently empty.
39     /// Returns the top-most `&T` in the `Stack`.
44     /// Pushes a `T` onto the `Stack`.
50     /// Pops the top-most `T` from the `Stack`.
59     /// Returns the size of the stack
64     /// Takes a snapshot of the current `Stack`.
74     /// Rewinds the `Stack` to the most recent `snapshot()`. If no `snapshot()` has been taken, this
75     /// function return the stack to its initial state.
89     // Rewind the stack to a particular index
105 impl<T: Clone> Index<Range<usize>> for Stack<T> {  implementation
121     use super::Stack;
125         let mut stack = Stack::new();  in snapshot_with_empty()  localVariable
127         stack.snapshot();  in snapshot_with_empty()
129         assert!(stack.is_empty());  in snapshot_with_empty()
131         stack.push(0);  in snapshot_with_empty()
132         stack.restore();  in snapshot_with_empty()
133         assert!(stack.is_empty());  in snapshot_with_empty()
138         let mut stack = Stack::new();  in snapshot_twice()  localVariable
140         stack.push(0);  in snapshot_twice()
142         stack.snapshot();  in snapshot_twice()
143         stack.snapshot();  in snapshot_twice()
144         stack.restore();  in snapshot_twice()
145         stack.restore();  in snapshot_twice()
147         assert_eq!(stack[0..stack.len()], [0]);  in snapshot_twice()
152         let mut stack = Stack::new();  in stack_ops()  localVariable
155         assert!(stack.is_empty());  in stack_ops()
156         assert_eq!(stack.peek(), None);  in stack_ops()
157         assert_eq!(stack.pop(), None);  in stack_ops()
160         stack.push(0);  in stack_ops()
161         assert!(!stack.is_empty());  in stack_ops()
162         assert_eq!(stack.peek(), Some(&0));  in stack_ops()
165         stack.push(1);  in stack_ops()
166         assert!(!stack.is_empty());  in stack_ops()
167         assert_eq!(stack.peek(), Some(&1));  in stack_ops()
170         assert_eq!(stack.pop(), Some(1));  in stack_ops()
171         assert!(!stack.is_empty());  in stack_ops()
172         assert_eq!(stack.peek(), Some(&0));  in stack_ops()
175         stack.push(2);  in stack_ops()
176         assert!(!stack.is_empty());  in stack_ops()
177         assert_eq!(stack.peek(), Some(&2));  in stack_ops()
180         stack.push(3);  in stack_ops()
181         assert!(!stack.is_empty());  in stack_ops()
182         assert_eq!(stack.peek(), Some(&3));  in stack_ops()
184         // Take a snapshot of the current stack  in stack_ops()
186         stack.snapshot();  in stack_ops()
189         assert_eq!(stack.pop(), Some(3));  in stack_ops()
190         assert!(!stack.is_empty());  in stack_ops()
191         assert_eq!(stack.peek(), Some(&2));  in stack_ops()
193         // Take a snapshot of the current stack  in stack_ops()
195         stack.snapshot();  in stack_ops()
198         assert_eq!(stack.pop(), Some(2));  in stack_ops()
199         assert!(!stack.is_empty());  in stack_ops()
200         assert_eq!(stack.peek(), Some(&0));  in stack_ops()
203         assert_eq!(stack.pop(), Some(0));  in stack_ops()
204         assert!(stack.is_empty());  in stack_ops()
208         stack.restore();  in stack_ops()
209         assert_eq!(stack.pop(), Some(2));  in stack_ops()
210         assert_eq!(stack.pop(), Some(0));  in stack_ops()
211         assert_eq!(stack.pop(), None);  in stack_ops()
215         stack.restore();  in stack_ops()
216         assert_eq!(stack.pop(), Some(3));  in stack_ops()
217         assert_eq!(stack.pop(), Some(2));  in stack_ops()
218         assert_eq!(stack.pop(), Some(0));  in stack_ops()
219         assert_eq!(stack.pop(), None);  in stack_ops()