refactor(Noder): optimize line splitting using ReadOnlySpan

src/CommonNovel/Noder.cs

@@ -9,34 +9,40 @@ public partial class Compiler
     /// <returns>Nodes</returns>
     public static string[] Noder(string input)
     {
-        string[] lines = [];
-        string[] nodes = [];
+        ReadOnlySpan<char> inputSpan = input.AsSpan();
+        List<string> nodeList = [];
 
-        using (StringReader reader = new(input))
+        int start = 0;
+        for (int i = 0; i < inputSpan.Length; i++)
         {
-            string? line;
-            while ((line = reader.ReadLine()) != null)
-            {
-                lines = [.. lines, line];
-            }
-        }
+            int? end = null;
+            if (inputSpan[i] != '\n') continue;
 
-        int i = 0;
-        foreach (var line in lines)
-        {
-            if (string.IsNullOrWhiteSpace(line))
+            // "\n\n" (LF) or "\r\n\r\n" (CRLF), "\n  \t\n" (tabs, spaces) => Split
+            for (int j = i + 1; j < inputSpan.Length; j++)
             {
-                i++;
-                continue;
+                if (inputSpan[j] == '\n')
+                {
+                    end = j + 1;
+                    break;
+                }
+                if (char.IsWhiteSpace(inputSpan[j]) || (inputSpan[i] == '\r'))
+                    continue;
+                else
+                    break;
             }
 
-            Array.Resize(ref nodes, i + 1);
-            if (string.IsNullOrWhiteSpace(nodes[i]))
-                nodes[i] = line;
-            else
-                nodes[i] += Environment.NewLine + line;
+            if (end is null) continue;
+
+            ReadOnlySpan<char> node = inputSpan[start..end.Value].Trim();
+            nodeList.Add(node.ToString());
+
+            start = end.Value;
         }
 
-        return nodes;
+        if (start < inputSpan.Length)
+            nodeList.Add(inputSpan[start..].Trim().ToString());
+
+        return nodeList.ToArray();
     }
 }

tests/CommonNovel.Tests/Noder.cs

@@ -1,3 +1,5 @@
+using System.Diagnostics.CodeAnalysis;
+
 namespace CommonNovel.Tests;
 
 public partial class CompilerUnitTest
@@ -17,31 +19,40 @@ public void TestNoder(string input, string[] expectedNodes)
         }
     }
 
-    private static readonly string Nl = Environment.NewLine;
-
+    [ExcludeFromCodeCoverage]
     public static IEnumerable<object[]> NoderTestData =>
         new List<object[]>
         {
             new object[] // CRLF
             {
                 "- Alice\r\n[Hi, Bob!]\r\n\r\n- Bob\r\n[Alice!]\r\n\r\n",
                 (string[])[
-                    $"- Alice{Nl}[Hi, Bob!]", // Future -> "\r\n"
-                    $"- Bob{Nl}[Alice!]" // Future -> "\r\n"
+                    "- Alice\r\n[Hi, Bob!]",
+                    "- Bob\r\n[Alice!]"
                 ]
             },
             new object[] // LF
             {
                 "- Alice\n[Hi, Bob!]\n\n- Bob\n[Alice!]\n\n",
                 (string[])[
-                    $"- Alice{Nl}[Hi, Bob!]", // Future -> '\n'
-                    $"- Bob{Nl}[Alice!]" // Future -> '\n'
+                    "- Alice\n[Hi, Bob!]",
+                    "- Bob\n[Alice!]"
                 ]
             },
             new object[] // three enters
             {
                 "\r\n\r\n\r\n",
-                (string[])[] // Future -> [ "", "" ]
+                (string[])[ "", "" ]
+            },
+            new object[] // single element
+            {
+                "- Alice",
+                (string[])[ "- Alice" ]
+            },
+            new object[] // spaces and tabs between newline-codes (\n or \r\n)
+            {
+                "\r\n  \t   \r\n",
+                (string[])[ "" ]
             }
         };
 }

tests/CommonNovel.Tests/Parser.cs

@@ -1,4 +1,6 @@
-namespace CommonNovel.Tests;
+using System.Diagnostics.CodeAnalysis;
+
+namespace CommonNovel.Tests;
 
 public partial class CompilerUnitTest
 {
@@ -20,6 +22,7 @@ public void TestParser(string inputNode, string[][] expectedAST)
         }
     }
 
+    [ExcludeFromCodeCoverage]
     public static IEnumerable<object[]> ParserTestData =>
         new List<object[]>
         {