From e23be8e952272c6006db23a5a3e3867171503208 Mon Sep 17 00:00:00 2001
From: Simon Cropp <simon.cropp@gmail.com>
Date: Fri, 16 Feb 2024 00:31:56 +1100
Subject: [PATCH] make EnglishArticle regex static

---
 src/Humanizer/ArticlePrefixSort.cs | 40 ++++++++++++++++--------------
 1 file changed, 21 insertions(+), 19 deletions(-)

diff --git a/src/Humanizer/ArticlePrefixSort.cs b/src/Humanizer/ArticlePrefixSort.cs
index 6d2b52440..f3f0029ce 100644
--- a/src/Humanizer/ArticlePrefixSort.cs
+++ b/src/Humanizer/ArticlePrefixSort.cs
@@ -7,6 +7,8 @@ namespace Humanizer
     /// </summary>
     public static class EnglishArticle
     {
+        static Regex _regex = new("^((The)|(the)|(a)|(A)|(An)|(an))\\s\\w+");
+
         /// <summary>
         /// Removes the prefixed article and appends it to the same string.
         /// </summary>
@@ -18,22 +20,21 @@ public static string[] AppendArticlePrefix(string[] items)
             {
                 throw new ArgumentOutOfRangeException(nameof(items));
             }
-
-            var regex = new Regex("^((The)|(the)|(a)|(A)|(An)|(an))\\s\\w+");
             var transformed = new string[items.Length];
 
             for (var i = 0; i < items.Length; i++)
             {
-                if (regex.IsMatch(items[i]))
+                var item = items[i];
+                if (_regex.IsMatch(item))
                 {
-                    var article = items[i].Substring(0, items[i].IndexOf(" ", StringComparison.CurrentCulture));
-                    var removed = items[i].Remove(0, items[i].IndexOf(" ", StringComparison.CurrentCulture));
+                    var article = item.Substring(0, item.IndexOf(" ", StringComparison.CurrentCulture));
+                    var removed = item.Remove(0, item.IndexOf(" ", StringComparison.CurrentCulture));
                     var appended = $"{removed} {article}";
                     transformed[i] = appended.Trim();
                 }
                 else
                 {
-                    transformed[i] = items[i].Trim();
+                    transformed[i] = item.Trim();
                 }
             }
             Array.Sort(transformed);
@@ -53,45 +54,46 @@ public static string[] PrependArticleSuffix(string[] appended)
             {
                 string suffix;
                 string original;
-                if (appended[i].EndsWith(EnglishArticles.The.ToString()))
+                var append = appended[i];
+                if (append.EndsWith(EnglishArticles.The.ToString()))
                 {
-                    suffix = appended[i].Substring(appended[i].IndexOf(" The", StringComparison.CurrentCulture));
+                    suffix = append.Substring(append.IndexOf(" The", StringComparison.CurrentCulture));
                     original = ToOriginalFormat(appended, suffix, i);
                     inserted[i] = original;
                 }
-                else if (appended[i].EndsWith(EnglishArticles.A.ToString()))
+                else if (append.EndsWith(EnglishArticles.A.ToString()))
                 {
-                    suffix = appended[i].Substring(appended[i].IndexOf(" A", StringComparison.CurrentCulture));
+                    suffix = append.Substring(append.IndexOf(" A", StringComparison.CurrentCulture));
                     original = ToOriginalFormat(appended, suffix, i);
                     inserted[i] = original;
                 }
-                else if (appended[i].EndsWith(EnglishArticles.An.ToString()))
+                else if (append.EndsWith(EnglishArticles.An.ToString()))
                 {
-                    suffix = appended[i].Substring(appended[i].IndexOf(" An", StringComparison.CurrentCulture));
+                    suffix = append.Substring(append.IndexOf(" An", StringComparison.CurrentCulture));
                     original = ToOriginalFormat(appended, suffix, i);
                     inserted[i] = original;
                 }
-                else if (appended[i].EndsWith(EnglishArticles.A.ToString().ToLowerInvariant()))
+                else if (append.EndsWith(EnglishArticles.A.ToString().ToLowerInvariant()))
                 {
-                    suffix = appended[i].Substring(appended[i].IndexOf(" a", StringComparison.CurrentCulture));
+                    suffix = append.Substring(append.IndexOf(" a", StringComparison.CurrentCulture));
                     original = ToOriginalFormat(appended, suffix, i);
                     inserted[i] = original;
                 }
-                else if (appended[i].EndsWith(EnglishArticles.An.ToString().ToLowerInvariant()))
+                else if (append.EndsWith(EnglishArticles.An.ToString().ToLowerInvariant()))
                 {
-                    suffix = appended[i].Substring(appended[i].IndexOf(" an", StringComparison.CurrentCulture));
+                    suffix = append.Substring(append.IndexOf(" an", StringComparison.CurrentCulture));
                     original = ToOriginalFormat(appended, suffix, i);
                     inserted[i] = original;
                 }
-                else if (appended[i].EndsWith(EnglishArticles.The.ToString().ToLowerInvariant()))
+                else if (append.EndsWith(EnglishArticles.The.ToString().ToLowerInvariant()))
                 {
-                    suffix = appended[i].Substring(appended[i].IndexOf(" the", StringComparison.CurrentCulture));
+                    suffix = append.Substring(append.IndexOf(" the", StringComparison.CurrentCulture));
                     original = ToOriginalFormat(appended, suffix, i);
                     inserted[i] = original;
                 }
                 else
                 {
-                    inserted[i] = appended[i];
+                    inserted[i] = append;
                 }
             }
             return inserted;