added Bind, Map and Match extensions generators

Railway.SourceGenerator/ResultBindExecutor.cs

@@ -0,0 +1,84 @@
+using System.Collections.Immutable;
+using System.Linq;
+using System.Text;
+using Microsoft.CodeAnalysis;
+
+namespace Just.Railway.SourceGen;
+
+internal sealed class ResultBindExecutor : ResultExtensionsExecutor
+{
+    protected override string ExtensionType => "Bind";
+
+    protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
+    {
+        var templateArgNames = Enumerable.Range(1, argCount)
+            .Select(i => $"T{i}")
+            .ToImmutableArray();
+        string separatedTemplateArgs = string.Join(", ", templateArgNames);
+
+        sb.AppendLine($"#region <{separatedTemplateArgs}>");
+
+        string resultValueType = templateArgNames.Length == 1 ? separatedTemplateArgs : $"({separatedTemplateArgs})";
+        string resultValueExpansion = GenerateResultValueExpansion(templateArgNames);
+
+        sb.AppendLine($$"""
+        [PureAttribute]
+        [GeneratedCodeAttribute("{{nameof(ResultBindExecutor)}}", "1.0.0.0")]
+        public static Result<R> Bind<{{separatedTemplateArgs}}, R>(this in Result<{{resultValueType}}> result, Func<{{separatedTemplateArgs}}, Result<R>> binding)
+        {
+            return result.State switch
+            {
+                ResultState.Success => binding({{resultValueExpansion}}),
+                ResultState.Error => result.Error!,
+                _ => throw new ResultNotInitializedException(nameof(result))
+            };
+        }
+        """);
+
+        sb.AppendLine($$"""
+        [PureAttribute]
+        [GeneratedCodeAttribute("{{nameof(ResultBindExecutor)}}", "1.0.0.0")]
+        public static Task<Result<R>> Bind<{{separatedTemplateArgs}}, R>(this in Result<{{resultValueType}}> result, Func<{{separatedTemplateArgs}}, Task<Result<R>>> binding)
+        {
+            return result.State switch
+            {
+                ResultState.Success => binding({{resultValueExpansion}}),
+                ResultState.Error => Task.FromResult<Result<R>>(result.Error!),
+                _ => throw new ResultNotInitializedException(nameof(result))
+            };
+        }
+        """);
+
+        sb.AppendLine($$"""
+        [PureAttribute]
+        [GeneratedCodeAttribute("{{nameof(ResultBindExecutor)}}", "1.0.0.0")]
+        public static async Task<Result<R>> Bind<{{separatedTemplateArgs}}, R>(this Task<Result<{{resultValueType}}>> resultTask, Func<{{separatedTemplateArgs}}, Result<R>> binding)
+        {
+            var result = await resultTask.ConfigureAwait(false);
+            return result.State switch
+            {
+                ResultState.Success => binding({{resultValueExpansion}}),
+                ResultState.Error => result.Error!,
+                _ => throw new ResultNotInitializedException(nameof(resultTask))
+            };
+        }
+        """);
+
+        sb.AppendLine($$"""
+        [PureAttribute]
+        [GeneratedCodeAttribute("{{nameof(ResultBindExecutor)}}", "1.0.0.0")]
+        public static async Task<Result<R>> Bind<{{separatedTemplateArgs}}, R>(this Task<Result<{{resultValueType}}>> resultTask, Func<{{separatedTemplateArgs}}, Task<Result<R>>> binding)
+        {
+            var result = await resultTask.ConfigureAwait(false);
+            return result.State switch
+            {
+                ResultState.Success => await binding({{resultValueExpansion}}).ConfigureAwait(false),
+                ResultState.Error => result.Error!,
+                _ => throw new ResultNotInitializedException(nameof(resultTask))
+            };
+        }
+        """);
+
+        sb.AppendLine("#endregion");
+    }
+}