From 94bc65d851375a14e68e61c7e98f09d549062e08 Mon Sep 17 00:00:00 2001
From: rektide <rektide@voodoowarez.com>
Date: Sat, 7 Feb 2015 14:04:15 -0500
Subject: [PATCH] Feature: sortOrder.

---
 modern/collection.js           |  1 +
 modern/collection/sortOrder.js | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 modern/collection/sortOrder.js

diff --git a/modern/collection.js b/modern/collection.js
index 2682db50..38b19f61 100644
--- a/modern/collection.js
+++ b/modern/collection.js
@@ -38,5 +38,6 @@ module.exports = {
   'some': require('./collection/some'),
   'sortBy': require('./collection/sortBy'),
   'sortByAll': require('./collection/sortByAll'),
+  'sortOrder': require('./collection/sortOrder'),
   'where': require('./collection/where')
 };
diff --git a/modern/collection/sortOrder.js b/modern/collection/sortOrder.js
new file mode 100644
index 00000000..9f5f68a8
--- /dev/null
+++ b/modern/collection/sortOrder.js
@@ -0,0 +1,29 @@
+var baseEach = require('../internal/baseEach'),
+    baseBinaryIndexBy = require('../internal/binaryIndexBy');
+
+/**
+ * Create a sorted index of array values, ascending from the index of the
+ * lowest item in the array up through index of the highest item in the array.
+ * @static
+ * @memberOf
+ * @category Collection
+ * @param {Array|Object|string} collection The collection to iterate over.
+ * @param {Function} [iteratee=_.identity] The function
+ *  invoked per iteration.
+ * @returns {Array} Returns the sorted index array.
+ * @example
+ *
+ * _.sortOrder([6, 4, 5]);
+ * // => [1, 2, 0]
+ */
+function sortOrder(collection, iteratee) {
+  var indexes = []
+  baseEach(collection, function(value, key) {
+    var index = baseBinaryIndexBy(indexes, key, function(value) { value = collection[value]; return iteratee ? iteratee(value) : value; });
+    indexes.splice(index, 0, key);
+  });
+
+  return indexes;
+}
+
+module.exports = sortOrder;