reductio/src/count.js

Reductio: Crossfilter groupings

var count = {
	add: function(prior, path, propName) {
		return function (p, v, nf) {
			if(prior) prior(p, v, nf);
			path(p)[propName]++;
			return p;
		};
	},
	remove: function(prior, path, propName) {
		return function (p, v, nf) {
			if(prior) prior(p, v, nf);
			path(p)[propName]--;
			return p;
		};
	},
	initial: function(prior, path, propName) {
		return function (p) {
			if(prior) p = prior(p);
			// if(p === undefined) p = {};
			path(p)[propName] = 0;
			return p;
		};
	}
};

export default count;