From 3b0d306c0fa20af4803fdad2313f250d4e388d35 Mon Sep 17 00:00:00 2001
From: James Smith <james@schoolshape.com>
Date: Wed, 6 Jun 2018 21:24:58 +0100
Subject: [PATCH] Optimization for Eq Array

Running Eq on large nested data structures can be expensive (think rose trees with 10^5 items), so checking for reference equality before traversing the array can result in some significant gains.
---
 src/Data/Eq.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/Data/Eq.js b/src/Data/Eq.js
index 1c62da2d..b8356847 100644
--- a/src/Data/Eq.js
+++ b/src/Data/Eq.js
@@ -9,6 +9,7 @@ exports.refEq = function (r1) {
 exports.eqArrayImpl = function (f) {
   return function (xs) {
     return function (ys) {
+      if (xs === ys) return true;
       if (xs.length !== ys.length) return false;
       for (var i = 0; i < xs.length; i++) {
         if (!f(xs[i])(ys[i])) return false;