35 lines
1.8 KiB
Markdown
35 lines
1.8 KiB
Markdown
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# L-SEQ - Fractional Indexing for List CRDTs
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This repository contains implementations of the L-SEQ algorithm for fractional indexing, used to create naive list CRDTs (Conflict-free Replicated Data Types). L-SEQ provides a way to generate unique, sortable identifiers that can be inserted between any two existing identifiers, making it ideal for collaborative editing and distributed systems.
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## Implementations
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- **TypeScript**: `@peoplesgrocers/lseq` - Located in the `typescript/` directory
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- **Rust**: `peoplesgrocers-lseq` - Located in the `rust/` directory
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## What is L-SEQ?
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L-SEQ is a sequence CRDT that uses fractional indexing to maintain a total order of elements in a distributed system. It allows multiple users to concurrently insert elements into a list without conflicts, automatically resolving the order based on the generated identifiers.
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## Usage
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Each implementation provides:
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- Allocation of new identifiers between existing ones
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- Comparison functions for sorting
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- Serialization to/from strings
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See the individual directories for language-specific documentation and examples.
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## References
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This library implements:
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[Brice Nédelec, Pascal Molli, Achour Mostefaoui, Emmanuel Desmontils. LSEQ: an Adaptive Structure
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for Sequences in Distributed Collaborative Editing. 13th ACM Symposium on Document Engineering
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(DocEng), Sep 2013, Florence, Italy. pp.37–46, 10.1145/2494266.2494278. hal-00921633](https://hal.science/hal-00921633/document)
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I recommend also reading:
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[Marc Shapiro, Nuno Preguiça, Carlos Baquero, Marek Zawirski. A comprehensive study of Conver-
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gent and Commutative Replicated Data Types. [Research Report] RR-7506, Inria – Centre Paris-
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Rocquencourt; INRIA. 2011, pp.50. inria-00555588](https://inria.hal.science/inria-00555588/document)
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