1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
|
use itertools::Itertools as _;
use super::{
Conversation, Id,
event::{Created, Deleted, Event},
};
use crate::event::Sequence;
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct History {
pub conversation: Conversation,
}
// State interface
impl History {
pub fn id(&self) -> &Id {
&self.conversation.id
}
// Snapshot of this conversation as it was when created. (Note to the future:
// it's okay if this returns a redacted or modified version of the conversation.
// If we implement renames by redacting the original name, then this should
// return the renamed conversation, not the original, even if that's not how
// it was "as created.")
pub fn as_created(&self) -> Conversation {
self.conversation.clone()
}
pub fn as_of<S>(&self, sequence: S) -> Option<Conversation>
where
S: Into<Sequence>,
{
self.events()
.filter(Sequence::up_to(sequence.into()))
.collect()
}
// Snapshot of this conversation as of all events recorded in this history.
pub fn as_snapshot(&self) -> Option<Conversation> {
self.events().collect()
}
}
// Event factories
impl History {
pub fn events(&self) -> impl Iterator<Item = Event> + use<> {
[self.created()]
.into_iter()
.merge_by(self.deleted(), Sequence::merge)
}
fn created(&self) -> Event {
Created {
conversation: self.conversation.clone(),
}
.into()
}
fn deleted(&self) -> Option<Event> {
self.conversation.deleted.map(|instant| {
Deleted {
instant,
id: self.conversation.id.clone(),
}
.into()
})
}
}
|