reductio/src/filter.js

Reductio: Crossfilter groupings

var filter = {
	// The big idea here is that you give us a filter function to run on values,
	// a 'prior' reducer to run (just like the rest of the standard reducers),
	// and a reference to the last reducer (called 'skip' below) defined before
	// the most recent chain of reducers.  This supports individual filters for
	// each .value('...') chain that you add to your reducer.
	add: function (filter, prior, skip) {
		return function (p, v, nf) {
			if (filter(v, nf)) {
				if (prior) prior(p, v, nf);
			} else {
				if (skip) skip(p, v, nf);
			}
			return p;
		};
	},
	remove: function (filter, prior, skip) {
		return function (p, v, nf) {
			if (filter(v, nf)) {
				if (prior) prior(p, v, nf);
			} else {
				if (skip) skip(p, v, nf);
			}
			return p;
		};
	}
};

export default filter;