@polymer/polymer/lib/utils/array-splice.d.ts

The Polymer library makes it easy to create your own web components. Give your element some markup and properties, and then use it on a site. Polymer provides features like dynamic templates and data binding to reduce the amount of boilerplate you need to

// tslint:disable:variable-name Describing an API that's defined elsewhere.
// tslint:disable:no-any describes the API as best we are able today

export {calculateSplices};


/**
 * Returns an array of splice records indicating the minimum edits required
 * to transform the `previous` array into the `current` array.
 *
 * Splice records are ordered by index and contain the following fields:
 * - `index`: index where edit started
 * - `removed`: array of removed items from this index
 * - `addedCount`: number of items added at this index
 *
 * This function is based on the Levenshtein "minimum edit distance"
 * algorithm. Note that updates are treated as removal followed by addition.
 *
 * The worst-case time complexity of this algorithm is `O(l * p)`
 *   l: The length of the current array
 *   p: The length of the previous array
 *
 * However, the worst-case complexity is reduced by an `O(n)` optimization
 * to detect any shared prefix & suffix between the two arrays and only
 * perform the more expensive minimum edit distance calculation over the
 * non-shared portions of the arrays.
 *
 * @returns Returns an array of splice record objects. Each of these
 * contains: `index` the location where the splice occurred; `removed`
 * the array of removed items from this location; `addedCount` the number
 * of items added at this location.
 */
declare function calculateSplices(current: any[], previous: any[]): any[];