From 8ee2fa5bca6f23f9ef9398a5a93f5fc991cbb01d Mon Sep 17 00:00:00 2001
From: Nat Quayle Nelson <natquaylenelson@gmail.com>
Date: Thu, 19 Nov 2020 12:48:22 -0700
Subject: [PATCH] Prelude.groups()

---
 src/kiss/Prelude.hx               | 15 +++++++++++++++
 src/test/cases/BasicTestCase.hx   |  5 +++++
 src/test/cases/BasicTestCase.kiss |  8 +++++++-
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/kiss/Prelude.hx b/src/kiss/Prelude.hx
index 894d794b..cfb49542 100644
--- a/src/kiss/Prelude.hx
+++ b/src/kiss/Prelude.hx
@@ -45,6 +45,21 @@ class Prelude {
         return if (a == b) a else Math.NaN;
     }
 
+    public static function groups<T>(a:Array<T>, size, keepRemainder = false) {
+        var numFullGroups = Math.floor(a.length / size);
+        var fullGroups = [
+            for (num in 0...numFullGroups) {
+                var start = num * size;
+                var end = (num + 1) * size;
+                a.slice(start, end);
+            }
+        ];
+        if (a.length % size != 0 && keepRemainder) {
+            fullGroups.push(a.slice(numFullGroups * size));
+        }
+        return fullGroups;
+    }
+
     // TODO put truthy in KissState
     // TODO make [] falsy
     public static dynamic function truthy(v:Any) {
diff --git a/src/test/cases/BasicTestCase.hx b/src/test/cases/BasicTestCase.hx
index 52ad5f81..323c2434 100644
--- a/src/test/cases/BasicTestCase.hx
+++ b/src/test/cases/BasicTestCase.hx
@@ -141,4 +141,9 @@ class BasicTestCase extends Test {
     function testTypeCheck() {
         Assert.equals(5, BasicTestCase.myTypeCheck());
     }
+
+    function testGroups() {
+        Assert.equals([[1, 2], [3, 4]].toString(), BasicTestCase.myGroups1().toString());
+        Assert.equals([[1, 2, 3], [4]].toString(), BasicTestCase.myGroups2().toString());
+    }
 }
diff --git a/src/test/cases/BasicTestCase.kiss b/src/test/cases/BasicTestCase.kiss
index 3cda7ab4..b23bc54f 100644
--- a/src/test/cases/BasicTestCase.kiss
+++ b/src/test/cases/BasicTestCase.kiss
@@ -85,4 +85,10 @@
         (catch [error] 7)))
 
 (defun myTypeCheck []
-    (the Int 5))
\ No newline at end of file
+    (the Int 5))
+
+(defun myGroups1 []
+    (Prelude.groups [1 2 3 4] 2))
+
+(defun myGroups2 []
+    (Prelude.groups [1 2 3 4] 3 true))
\ No newline at end of file