venryx/lexicon-fractional-index

Lexicon fractional indexing library, migrated from js

Lexicon Fractional Index

A Rust version for fractional-indexing . Keys in string and satisfy lexicographic order.

Rewritten from existed codebase:

• Go https://github.com/rocicorp/fracdex
• JavaScript https://github.com/rocicorp/fractional-indexing

Usage

Docs.

use lexicon_fractional_index::key_between;

// create an initial key
let k0 = key_between(&None, &None)?;

// two keys, notice that some strings are not valid keys
let left = "Xb0M".to_owned();
let right = "Xb0M0V".to_owned();

// new key at beginning
let next = key_between(&None, &Some(right.to_owned()))?;

// new key at end
let next = key_between(&Some(left.to_owned()), &None)?;

// new key between 2 keys
let next = key_between(&Some(left.to_owned()), &Some(right.to_owned()))?;

License

TODO