Fix #165.

README.md

@@ -24,7 +24,6 @@ If you use NPM, `npm install d3-scale`. Otherwise, download the [latest release]
 
 ```html
 <script src="https://d3js.org/d3-array.v1.min.js"></script>
-<script src="https://d3js.org/d3-collection.v1.min.js"></script>
 <script src="https://d3js.org/d3-color.v1.min.js"></script>
 <script src="https://d3js.org/d3-format.v1.min.js"></script>
 <script src="https://d3js.org/d3-interpolate.v1.min.js"></script>

package.json

@@ -30,7 +30,6 @@
   },
   "dependencies": {
     "d3-array": "^1.2.0",
-    "d3-collection": "1",
     "d3-format": "1",
     "d3-interpolate": "1",
     "d3-time": "1",

src/ordinal.js

@@ -1,11 +1,10 @@
-import {map} from "d3-collection";
 import {slice} from "./array";
 import {initRange} from "./init";
 
 export var implicit = {name: "implicit"};
 
 export default function ordinal() {
-  var index = map(),
+  var index = new Map(),
       domain = [],
       range = [],
       unknown = implicit;
@@ -21,7 +20,7 @@ export default function ordinal() {
 
   scale.domain = function(_) {
     if (!arguments.length) return domain.slice();
-    domain = [], index = map();
+    domain = [], index = new Map();
     var i = -1, n = _.length, d, key;
     while (++i < n) if (!index.has(key = (d = _[i]) + "")) index.set(key, domain.push(d));
     return scale;

yarn.lock

@@ -190,10 +190,6 @@ d3-array@^1.2.0:
   version "1.2.4"
   resolved "https://registry.yarnpkg.com/d3-array/-/d3-array-1.2.4.tgz#635ce4d5eea759f6f605863dbcfc30edc737f71f"
 
-d3-collection@1:
-  version "1.0.7"
-  resolved "https://registry.yarnpkg.com/d3-collection/-/d3-collection-1.0.7.tgz#349bd2aa9977db071091c13144d5e4f16b5b310e"
-
 d3-color@1:
   version "1.2.3"
   resolved "https://registry.yarnpkg.com/d3-color/-/d3-color-1.2.3.tgz#6c67bb2af6df3cc8d79efcc4d3a3e83e28c8048f"