antonsimola/fractionalindexing

Library for generating short string keys for keeping objects in lists in order

Fractional Indexing

This is based on JS implementation by rocicorp which in turn is based on Implementing Fractional Indexing by David Greenspan .

Use it to generate short string keys which help maintain ordered lists.

For example when reordering to-do items, drag and dropping between items, or as last / first one.

Usage

var key1 = OrderKeyGenerator.GenerateKeyBetween(null, null); // to get started
var key2 = OrderKeyGenerator.GenerateKeyBetween(key1, null); // after key1
var key3 = OrderKeyGenerator.GenerateKeyBetween(key1, key2); // between key1 and key2
var key0 = OrderKeyGenerator.GenerateKeyBetween(null, key1); // first one