Merged seq into index again

No point separating them right now, they're going to depend on each
other. Also means I can remove the lodash dependency.

Author: Olical

package.json

@@ -22,8 +22,5 @@
   },
   "bugs": {
     "url": "https://github.com/Wolfy87/lazy-array/issues"
-  },
-  "dependencies": {
-    "lodash": "^3.9.2"
   }
 }

src/index.js

@@ -1,8 +1,6 @@
 'use strict';
 
-var _ = require('lodash');
 var LazyArray = require('./LazyArray');
-var seq = require('./seq');
 
 /**
  * Constructs a lazy array instance.
@@ -13,8 +11,57 @@ var seq = require('./seq');
 function create(fn) {
     return new LazyArray(fn);
 }
+/**
+ * Get the first item in an array.
+ *
+ * @param {*[]} list
+ * @return {*} First item.
+ */
+function first(list) {
+    if (LazyArray.isLazyArray(list)) {
+        return list.fn()[0];
+    }
+    else {
+        return Array.isArray(list) ? list[0] : null;
+    }
+}
+
+/**
+ * Get the tail of the array.
+ *
+ * @param {*[]} list
+ * @return {*[]} Tail.
+ */
+function rest(list) {
+    if (LazyArray.isLazyArray(list)) {
+        return list.fn()[1];
+    }
+    else {
+        return Array.isArray(list) ? list.slice(1) : [];
+    }
+}
+
+/**
+ * Constructs a new array by prepending the item on the list. When given a
+ * LazyArray instance to cons onto, it will return a value/LazyArray pair.
+ *
+ * @param {*} item
+ * @param {*[]} list
+ * @return {*[]} Original list with the item at the front.
+ */
+function cons(item, list) {
+    if (LazyArray.isLazyArray(list)) {
+        return [item, list];
+    }
+    else {
+        return [item].concat(Array.isArray(list) ? list : []);
+    }
+}
 
-module.exports = _.assign({
+module.exports = {
     LazyArray: LazyArray,
-    create: create
-}, seq);
+    create: create,
+    first: first,
+    rest: rest,
+    cons: cons
+};