Added halve module

Author: klaudiosinani

index.js

@@ -57,6 +57,7 @@ const gcd = require('./src/gcd')
 const getNth = require('./src/get-nth')
 const gt = require('./src/gt')
 const gte = require('./src/gte')
+const halve = require('./src/halve.js')
 const hasProp = require('./src/has-prop')
 const head = require('./src/head')
 const id = require('./src/id')
@@ -250,6 +251,7 @@ module.exports = {
   getNth,
   gt,
   gte,
+  halve,
   hasProp,
   head,
   id,

src/halve.js

@@ -0,0 +1,18 @@
+'use strict'
+const and = require('./and')
+const curry = require('./curry')
+const div = require('./div')
+const len = require('./len')
+const notArr = require('./not-arr')
+const notStr = require('./not-str')
+const partitionAt = require('./partition-at')
+const trunc = require('./trunc')
+
+function halve(xs) {
+  if (and(notArr(xs), notStr(xs)))
+    throw new TypeError('[halve] Argument must be an array or a string')
+
+  return partitionAt(trunc(div(len(xs), 2)), xs)
+}
+
+module.exports = curry(halve)