From 07a54e89dd58a055ab91cd7561977ca80bf686e4 Mon Sep 17 00:00:00 2001
From: Adnan Maolood <me@adnano.co>
Date: Wed, 12 May 2021 17:10:19 -0400
Subject: [PATCH] funcs: Add reverse

---
 funcs.go | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/funcs.go b/funcs.go
index 90de897..307ab80 100644
--- a/funcs.go
+++ b/funcs.go
@@ -3,11 +3,13 @@ package main
 import (
 	"html/template"
 	"path"
+	"reflect"
 	"strings"
 )
 
 var funcs = map[string]interface{}{
 	"path":         func() _path { return _path{} },
+	"reverse":      reverse,
 	"strings":      func() _strings { return _strings{} },
 	"safeHTML":     func(s string) template.HTML { return template.HTML(s) },
 	"safeHTMLAttr": func(s string) template.HTMLAttr { return template.HTMLAttr(s) },
@@ -44,3 +46,15 @@ func (_strings) TrimPrefix(a, b string) string        { return strings.TrimPrefi
 func (_strings) TrimRight(a, b string) string         { return strings.TrimRight(a, b) }
 func (_strings) TrimSpace(s string) string            { return strings.TrimSpace(s) }
 func (_strings) TrimSuffix(a, b string) string        { return strings.TrimSuffix(a, b) }
+
+func reverse(s interface{}) interface{} {
+	v := reflect.ValueOf(s)
+	n := v.Len()
+	r := reflect.MakeSlice(v.Type(), n, n)
+	reflect.Copy(r, v)
+	swap := reflect.Swapper(r.Interface())
+	for i, j := 0, n-1; i < j; i, j = i+1, j-1 {
+		swap(i, j)
+	}
+	return r.Interface()
+}