extract partitionByIndex

Author: hawkrives

source/lib/partition-by-index.js

@@ -0,0 +1,12 @@
+// @flow
+
+export function partitionByIndex<T>(arr: T[]): [T[], T[]] {
+  return arr.reduce(
+    (acc, val, idx) => {
+      return idx % 2 === 0
+        ? [acc[0].concat(val), acc[1]]
+        : [acc[0], acc[1].concat(val)]
+    },
+    [[], []],
+  )
+}