#170 - Structure is read-only list

Author: Stepami

Directory.Packages.props

@@ -14,6 +14,7 @@
     <PackageVersion Include="System.IO.Abstractions" Version="22.0.16" />
     <PackageVersion Include="Visitor.NET" Version="4.2.0" />
     <PackageVersion Include="Visitor.NET.AutoVisitableGen" Version="1.5.2" />
+    <PackageVersion Include="ZLinq" Version="1.5.2" />
     <PackageVersion Include="ZLogger" Version="2.5.10" />
     <PackageVersion Include="ZString" Version="2.6.0" />
   </ItemGroup>

src/Domain/HydraScript.Domain.FrontEnd/HydraScript.Domain.FrontEnd.csproj

@@ -3,6 +3,7 @@
     <ItemGroup>
         <PackageReference Include="Visitor.NET" />
         <PackageReference Include="Visitor.NET.AutoVisitableGen" PrivateAssets="all" />
+        <PackageReference Include="ZLinq" />
         <PackageReference Include="ZString" />
     </ItemGroup>
 

src/Domain/HydraScript.Domain.FrontEnd/Lexer/IStructure.cs

@@ -3,7 +3,7 @@
 
 namespace HydraScript.Domain.FrontEnd.Lexer;
 
-public interface IStructure : IEnumerable<TokenType>
+public interface IStructure : IReadOnlyList<TokenType>
 {
     public Regex Regex { get; }
 

src/Domain/HydraScript.Domain.FrontEnd/Lexer/ITokenTypesProvider.cs

@@ -1,8 +1,9 @@
+using System.Collections.Frozen;
 using HydraScript.Domain.FrontEnd.Lexer.TokenTypes;
 
 namespace HydraScript.Domain.FrontEnd.Lexer;
 
 public interface ITokenTypesProvider
 {
-    IEnumerable<TokenType> GetTokenTypes();
+    FrozenDictionary<string, TokenType> GetTokenTypes();
 }

src/Domain/HydraScript.Domain.FrontEnd/Lexer/Impl/RegexLexer.cs

@@ -24,8 +24,9 @@ public IEnumerator<Token> GetEnumerator()
     {
         foreach (Match match in Structure.Regex.Matches(_text))
         {
-            foreach (var type in Structure)
+            for (var i = 0; i < Structure.Count; i++)
             {
+                var type = Structure[i];
                 var group = match.Groups[type.Tag];
 
                 if (!group.Success || type.CanIgnore()) continue;

src/Domain/HydraScript.Domain.FrontEnd/Lexer/Impl/Structure.cs

@@ -10,9 +10,7 @@ namespace HydraScript.Domain.FrontEnd.Lexer.Impl;
 public class Structure<TContainer>(ITokenTypesProvider provider) : IStructure
     where TContainer : IGeneratedRegexContainer
 {
-    private FrozenDictionary<string, TokenType> Types { get; } = provider.GetTokenTypes()
-        .Concat([new EndOfProgramType(), new ErrorType()])
-        .ToFrozenDictionary(x => x.Tag);
+    private FrozenDictionary<string, TokenType> Types { get; } = provider.GetTokenTypes();
 
     public Regex Regex { get; } = TContainer.Regex;
 
@@ -27,4 +25,8 @@ public IEnumerator<TokenType> GetEnumerator() =>
 
     [ExcludeFromCodeCoverage]
     IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+
+    public int Count => Types.Values.Length;
+
+    public TokenType this[int index] => Types.Values[index];
 }

src/Domain/HydraScript.Domain.FrontEnd/Lexer/Impl/TokenTypesProvider.cs

@@ -1,13 +1,17 @@
+using System.Collections.Frozen;
 using HydraScript.Domain.FrontEnd.Lexer.TokenTypes;
+using ZLinq;
 
 namespace HydraScript.Domain.FrontEnd.Lexer.Impl;
 
 public class TokenTypesProvider : ITokenTypesProvider
 {
-    public IEnumerable<TokenType> GetTokenTypes() =>
-        Constants.TokenTypes.Stream
+    public FrozenDictionary<string, TokenType> GetTokenTypes() =>
+        Constants.TokenTypes.Stream.AsValueEnumerable()
             .OrderBy(x => x.Priority)
             .Select(x => x.CanIgnore
                 ? new IgnorableType(x.Tag)
-                : new TokenType(x.Tag));
+                : new TokenType(x.Tag))
+            .Concat([new EndOfProgramType(), new ErrorType()])
+            .ToFrozenDictionary(x => x.Tag);
 }

tests/HydraScript.UnitTests/Domain/FrontEnd/StructureTests.cs

@@ -1,3 +1,4 @@
+using System.Collections.Frozen;
 using HydraScript.Domain.FrontEnd.Lexer;
 using HydraScript.Domain.FrontEnd.Lexer.Impl;
 using HydraScript.Domain.FrontEnd.Lexer.TokenTypes;
@@ -14,7 +15,7 @@ public void ToStringCorrectTest()
         {
             new("MyToken"),
             new("OneToSeven")
-        };
+        }.ToFrozenDictionary(x => x.Tag);
         var provider = Substitute.For<ITokenTypesProvider>();
         provider.GetTokenTypes().Returns(tokenTypes);
         var structure = new Structure<GeneratedRegexContainer>(provider);