Index: node_modules/d3-interpolate/src/string.js
===================================================================
--- node_modules/d3-interpolate/src/string.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-interpolate/src/string.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,64 @@
+import number from "./number.js";
+
+var reA = /[-+]?(?:\d+\.?\d*|\.?\d+)(?:[eE][-+]?\d+)?/g,
+    reB = new RegExp(reA.source, "g");
+
+function zero(b) {
+  return function() {
+    return b;
+  };
+}
+
+function one(b) {
+  return function(t) {
+    return b(t) + "";
+  };
+}
+
+export default function(a, b) {
+  var bi = reA.lastIndex = reB.lastIndex = 0, // scan index for next number in b
+      am, // current match in a
+      bm, // current match in b
+      bs, // string preceding current number in b, if any
+      i = -1, // index in s
+      s = [], // string constants and placeholders
+      q = []; // number interpolators
+
+  // Coerce inputs to strings.
+  a = a + "", b = b + "";
+
+  // Interpolate pairs of numbers in a & b.
+  while ((am = reA.exec(a))
+      && (bm = reB.exec(b))) {
+    if ((bs = bm.index) > bi) { // a string precedes the next number in b
+      bs = b.slice(bi, bs);
+      if (s[i]) s[i] += bs; // coalesce with previous string
+      else s[++i] = bs;
+    }
+    if ((am = am[0]) === (bm = bm[0])) { // numbers in a & b match
+      if (s[i]) s[i] += bm; // coalesce with previous string
+      else s[++i] = bm;
+    } else { // interpolate non-matching numbers
+      s[++i] = null;
+      q.push({i: i, x: number(am, bm)});
+    }
+    bi = reB.lastIndex;
+  }
+
+  // Add remains of b.
+  if (bi < b.length) {
+    bs = b.slice(bi);
+    if (s[i]) s[i] += bs; // coalesce with previous string
+    else s[++i] = bs;
+  }
+
+  // Special optimization for only a single match.
+  // Otherwise, interpolate each of the numbers and rejoin the string.
+  return s.length < 2 ? (q[0]
+      ? one(q[0].x)
+      : zero(b))
+      : (b = q.length, function(t) {
+          for (var i = 0, o; i < b; ++i) s[(o = q[i]).i] = o.x(t);
+          return s.join("");
+        });
+}