reductio/src/sum.js

Reductio: Crossfilter groupings

var sum = {
	add: function (a, prior, path) {
		return function (p, v, nf) {
			if(prior) prior(p, v, nf);
			path(p).sum = path(p).sum + a(v);
			return p;
		};
	},
	remove: function (a, prior, path) {
		return function (p, v, nf) {
			if(prior) prior(p, v, nf);
			path(p).sum = path(p).sum - a(v);
			return p;
		};
	},
	initial: function (prior, path) {
		return function (p) {
			p = prior(p);
			path(p).sum = 0;
			return p;
		};
	}
};

export default sum;