trait State {
fn request_review(&self) -> Box<dyn State>;
- fn approve(&self) -> Box<dyn State>;
+ fn approve(&mut self) -> Box<dyn State>;
fn reject(&self) -> Box<dyn State>;
#[allow(unused_variables)]
struct Draft {}
impl State for Draft {
fn request_review(&self) -> Box<dyn State> {
- Box::new(PendingReview {})
+ Box::new(PendingReview {acks: 0})
}
- fn approve(&self) -> Box<dyn State> {
+ fn approve(&mut self) -> Box<dyn State> {
// don't change state
Box::new(Self {})
}
}
}
-struct PendingReview {}
+struct PendingReview {
+ acks: u32,
+}
+
impl State for PendingReview {
fn request_review(&self) -> Box<dyn State> {
- Box::new(Self {})
+ Box::new(Self {acks: self.acks})
}
- fn approve(&self) -> Box<dyn State> {
- Box::new(Published {})
+ fn approve(&mut self) -> Box<dyn State> {
+ if self.acks >= 1 {
+ Box::new(Published {})
+ } else {
+ Box::new(Self {acks: self.acks + 1})
+ }
}
fn reject(&self) -> Box<dyn State> {
Box::new(Self {})
}
- fn approve(&self) -> Box<dyn State> {
+ fn approve(&mut self) -> Box<dyn State> {
Box::new(Published {})
}