added Bind, Map and Match extensions generators

Railway.SourceGenerator/ResultExtensionsExecutor.cs

@@ -0,0 +1,65 @@
+using System.Collections.Immutable;
+using System.Text;
+using Microsoft.CodeAnalysis;
+
+namespace Just.Railway.SourceGen;
+
+internal abstract class ResultExtensionsExecutor : IGeneratorExecutor
+{
+    public void Execute(SourceProductionContext context, Compilation source)
+    {
+        var methods = GenerateMethods();
+        var code = $$"""
+        #nullable enable
+        using System;
+        using System.Collections.Generic;
+        using System.Diagnostics.Contracts;
+        using System.CodeDom.Compiler;
+
+        namespace Just.Railway;
+
+        public static partial class ResultExtensions
+        {
+        {{methods}}
+        }
+        """;
+
+        context.AddSource($"ResultExtensions.{ExtensionType}.g.cs", code);
+    }
+
+    private string GenerateMethods()
+    {
+        var sb = new StringBuilder();
+
+        for (int i = 1; i <= Constants.MaxResultTupleSize; i++)
+        {
+            GenerateMethodsForArgCount(sb, argCount: i);
+        }
+
+        return sb.ToString();
+    }
+
+    protected string GenerateResultValueExpansion(ImmutableArray<string> templateArgNames)
+    {
+        string resultExpansion;
+        if (templateArgNames.Length > 1)
+        {
+            var resultExpansionBuilder = new StringBuilder();
+            for (int i = 1; i <= templateArgNames.Length; i++)
+            {
+                resultExpansionBuilder.Append($"result.Value.Item{i}, ");
+            }
+            resultExpansionBuilder.Remove(resultExpansionBuilder.Length - 2, 2);
+            resultExpansion = resultExpansionBuilder.ToString();
+        }
+        else
+        {
+            resultExpansion = "result.Value";
+        }
+
+        return resultExpansion;
+    }
+
+    protected abstract string ExtensionType { get; }
+    protected abstract void GenerateMethodsForArgCount(StringBuilder sb, int argCount);
+}