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//pub struct Post {
// state: Option<Box<dyn State>>,
// content: String,
//}
//
//impl Post {
// pub fn new() -> Post {
// Post {
// state: Some(Box::new(Draft {})),
// content: String::new(),
// }
// }
//
// pub fn add_text(&mut self, text: &str) {
// self.content.push_str(text);
// }
//
// pub fn content(&self) -> &str {
// self.state.as_ref().unwrap().content(&self)
// }
//
// pub fn request_review(&mut self) {
// if let Some(s) = self.state.take() {
// self.state = Some(s.request_review())
// }
// }
//
// pub fn approve(&mut self) {
// if let Some(s) = self.state.take() {
// self.state = Some(s.approve())
// }
// }
//}
//
//trait State {
// fn request_review(self: Box<Self>) -> Box<dyn State>;
// fn approve(self: Box<Self>) -> Box<dyn State>;
// fn content<'a>(&self, post: &'a Post) -> &'a str {
// ""
// }
//}
//
//struct Draft {}
//
//impl State for Draft {
// fn request_review(self: Box<Self>) -> Box<dyn State> {
// Box::new(PendingReview {})
// }
//
// fn approve(self: Box<Self>) -> Box<dyn State> {
// self
// }
//}
//
//struct PendingReview {}
//
//impl State for PendingReview {
// fn request_review(self: Box<Self>) -> Box<dyn State> {
// self
// }
//
// fn approve(self: Box<Self>) -> Box<dyn State> {
// Box::new(Published {})
// }
//}
//
//struct Published {}
//
//impl State for Published {
// fn request_review(self: Box<Self>) -> Box<dyn State> {
// self
// }
//
// fn approve(self: Box<Self>) -> Box<dyn State> {
// self
// }
//
// fn content<'a>(&self, post: &'a Post) -> &'a str {
// &post.content
// }
//}
pub struct Post {
content: String,
}
pub struct DraftPost {
content: String,
}
pub struct PendingReviewPost {
content: String,
}
impl Post {
pub fn new() -> DraftPost {
DraftPost {
content: String::new(),
}
}
pub fn content(&self) -> &str {
&self.content
}
}
impl DraftPost {
pub fn add_text(&mut self, text: &str) {
self.content.push_str(text);
}
pub fn request_review(self) -> PendingReviewPost {
PendingReviewPost {
content: self.content,
}
}
}
impl PendingReviewPost {
pub fn approve(self) -> Post {
Post {
content: self.content,
}
}
}
|
