Coax1d digital cash solution #8
Conversation
…f/blockchain-from-scratch into coax1d-digital-cash-exercise
| } | ||
|
|
||
| fn handle_transfer(starting_state: State, spends: Vec<Bill>, receives: Vec<Bill>) -> State { | ||
| if spends.is_empty() || receives.is_empty() { |
There was a problem hiding this comment.
It should be okay if there are no receives. This is how you burn.
| let mut next_state = starting_state.clone(); | ||
|
|
||
| { | ||
| let input_set: BTreeSet<_> = spends.iter().collect(); |
There was a problem hiding this comment.
Why not just just the same HashMap that we already used?
There was a problem hiding this comment.
This is true. I was just rushing trying to get this out asap.
| if total_input.checked_add(amount).is_none() { | ||
| return starting_state; | ||
| } |
There was a problem hiding this comment.
This is checking for an overflow right? I wonder if we should add a test to make sure this is handled correctly. Or if we want to keep this simple and not worry about overflow, you could just do normal addition here.
There was a problem hiding this comment.
Ya I can add one. Thanks for the catch
| if output.serial != next_state.next_serial { | ||
| return starting_state; | ||
| } |
There was a problem hiding this comment.
This made me realize that I didn't design the problem in the nicest way for the user. It would be nice if we didn't require the user to provide the next serial number but rather we just made them provide the owner and amount, then fill the correct serial here. Maybe too big of a change at this point, but figured I'd share the thought.
There was a problem hiding this comment.
I am going to say for next iteration we can make it simpler. I just dont have time to continue on this have to move on to the other stuff. I am almost finished with the p2p lec now.
| @@ -28,7 +28,7 @@ pub trait StateMachine { | |||
| } | |||
|
|
|||
| /// A set of play users for experimenting with the multi-user state machines | |||
| #[derive(Hash, Eq, PartialEq, Debug, Clone)] | |||
| #[derive(Hash, Eq, PartialEq, Debug, Clone, Ord, PartialOrd)] | |||
There was a problem hiding this comment.
I think we also won't need these traits if we use a HashMap for deduplicating
name says it all