README.md

kdiff

Simple O(n) diffing library

This is a simple Kotlin library I built to try out the following tech stack:

• Kotlin (main language)
• Gradle - Kotlin DSL (build system)
• Spek (BDD style unit testing framework)
• Expekt (expectation style assertions)

The differ will take two collections, an old and new, and a lambda for extracting a Pair that:

1. Represents a key for determining which values in the collections are for the same data element / field
2. Represents the value for each element in the collection

Example Usage:

import ca.snasir.kdiff

// Input dataset
val oldCollection = listOf(Element(1, "a"), Element(2, "b"))
val newCollection = listOf(Element(2, "c"), Element(3, "d"))

// Instantiate the differ with a key-value extraction lambda
val differ = Differ({ it: Element -> KeyValuePair(it.key, it.value) })

// Run differ in O(n) time
val diffs = differ.diffChanges(oldCollection, newCollection)

The resulting diffs will be of type Changes<Int, String>.