monocle-ts/es6/At/Record.js

A porting of scala monocle library to TypeScript

/**
 * @since 1.7.0
 */
import { At, Lens } from '..';
import { isNone } from 'fp-ts/es6/Option';
import * as R from 'fp-ts/es6/Record';
/**
 * @category constructor
 * @since 1.7.0
 */
export function atRecord() {
    return new At(function (k) {
        return new Lens(function (r) { return R.lookup(k, r); }, function (oa) { return function (r) {
            if (isNone(oa)) {
                return R.deleteAt(k)(r);
            }
            else {
                return R.insertAt(k, oa.value)(r);
            }
        }; });
    });
}