reductio/src/sortBy.js

Reductio: Crossfilter groupings

var pluck_n = function (n) {
    if (typeof n === 'function') {
        return n;
    }
    if (~n.indexOf('.')) {
        var split = n.split('.');
        return function (d) {
            return split.reduce(function (p, v) {
                return p[v];
            }, d);
        };
    }
    return function (d) {
        return d[n];
    };
};

function ascending(a, b) {
    return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
}

var comparer = function (accessor, ordering) {
    return function (a, b) {
        return ordering(accessor(a), accessor(b));
    };
};

export default function (prior) {
    return function (value, order) {
        if (arguments.length === 1) {
            order = ascending;
        }
        return prior().sort(comparer(pluck_n(value), order));
    };
}