d3-jsnext/src/interpolate/object.js

d3, but futuristic

import { d3_interpolate } from './interpolate';

var d3_interpolateObject;

d3$interpolateObject = d3_interpolateObject;

function d3_interpolateObject(a, b) {
  var i = {},
      c = {},
      k;
  for (k in a) {
    if (k in b) {
      i[k] = d3_interpolate(a[k], b[k]);
    } else {
      c[k] = a[k];
    }
  }
  for (k in b) {
    if (!(k in a)) {
      c[k] = b[k];
    }
  }
  return function(t) {
    for (k in i) c[k] = i[k](t);
    return c;
  };
}

export { d3_interpolateObject };