[−][src]Crate operational_transform
A library for Operational Transformation
Operational transformation (OT) is a technology for supporting a range of collaboration functionalities in advanced collaborative software systems. [1]
When working on the same document over the internet concurrent operations from multiple users might be in conflict. Operational Transform can help to resolve conflicts in such a way that docuemnts stay in sync.
The basic operations that are supported are:
- Retain(n): Move the cursor
n
positions forward - Delete(n): Delete
n
characters at the current position - Insert(s): Insert the string
s
at the current position
This library can be used to...
... compose sequences of operations:
use operational_transform::OperationSeq; let mut a = OperationSeq::default(); a.insert("abc"); let mut b = OperationSeq::default(); b.retain(3); b.insert("def"); let after_a = a.apply("").unwrap(); let after_b = b.apply(&after_a).unwrap(); let c = a.compose(&b).unwrap(); let after_ab = a.compose(&b).unwrap().apply("").unwrap(); assert_eq!(after_ab, after_b);
... transform sequences of operations
use operational_transform::OperationSeq; let s = "abc"; let mut a = OperationSeq::default(); a.retain(3); a.insert("def"); let mut b = OperationSeq::default(); b.retain(3); b.insert("ghi"); let (a_prime, b_prime) = a.transform(&b).unwrap(); let ab_prime = a.compose(&b_prime).unwrap(); let ba_prime = b.compose(&a_prime).unwrap(); let after_ab_prime = ab_prime.apply(s).unwrap(); let after_ba_prime = ba_prime.apply(s).unwrap(); assert_eq!(ab_prime, ba_prime); assert_eq!(after_ab_prime, after_ba_prime);
... invert sequences of operations
use operational_transform::OperationSeq; let s = "abc"; let mut o = OperationSeq::default(); o.retain(3); o.insert("def"); let p = o.invert(s); assert_eq!(p.apply(&o.apply(s).unwrap()).unwrap(), s);
Features
Serialisation is supporeted by using the serde
feature.
- Delete(n) will be serialized to -n
- Insert(s) will be serialized to "{s}"
- Retain(n) will be serailized to n
use operational_transform::OperationSeq; use serde_json; let o: OperationSeq = serde_json::from_str("[1,-1,\"abc\"]").unwrap(); let mut o_exp = OperationSeq::default(); o_exp.retain(1); o_exp.delete(1); o_exp.insert("abc"); assert_eq!(o, o_exp);
Acknowledgement
In the current state the code is ported from here. It might change in the future as there is much room for optimisation and also usability.
Structs
OTError | Error for failed operational transform operations. |
OperationSeq | A sequence of |
Enums
Operation | A single operation to be executed at the cursor's current position. |