Function invertRange

docs/app/js/sanddance-app.js:126650–126663

(scale1)

const Interpolating = "interpolating";
const Temporal = "temporal";
function invertRange(scale1) {
    return function(_) {
        let lo = _[0], hi = _[1], t;
        if (hi < lo) {
            t = lo;
            lo = hi;
            hi = t;
        }
        return [
            scale1.invert(lo),
            scale1.invert(hi)
        ];
    };
}
function invertRangeExtent(scale2) {
    return function(_) {
        const range = scale2.range();