added TryRecover extensions

Railway.SourceGenerator/ResultTryRecoverExecutor.cs

@@ -0,0 +1,86 @@
+using System.Collections.Immutable;
+using System.Linq;
+using System.Text;
+using Microsoft.CodeAnalysis;
+
+namespace Just.Railway.SourceGen;
+
+internal sealed class ResultTryRecoverExecutor : ResultExtensionsExecutor
+{
+    protected override string ExtensionType => "TryRecover";
+    protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
+    {
+        if (argCount > 1) return;
+        
+        var templateArgNames = Enumerable.Repeat("T", argCount)
+            .ToImmutableArray();
+
+        string methodTemplateDecl = GenerateTemplateDecl(templateArgNames);
+        string resultTypeDef = GenerateResultTypeDef(templateArgNames);
+
+        sb.AppendLine($"#region {resultTypeDef}");
+
+        sb.AppendLine($$"""
+        [PureAttribute]
+        [GeneratedCodeAttribute("{{nameof(ResultTryRecoverExecutor)}}", "1.0.0.0")]
+        public static {{resultTypeDef}} TryRecover{{methodTemplateDecl}}(this in {{resultTypeDef}} result, Func<Error, {{resultTypeDef}}> recover)
+        {
+            return result.State switch
+            {
+                ResultState.Success => ({{resultTypeDef}})result.Value,
+                ResultState.Error => recover(result.Error!),
+                _ => throw new ResultNotInitializedException(nameof(result))
+            };
+        }
+        """);
+
+        GenerateAsyncMethods("Task", sb, templateArgNames, resultTypeDef, methodTemplateDecl);
+        GenerateAsyncMethods("ValueTask", sb, templateArgNames, resultTypeDef, methodTemplateDecl);
+
+        sb.AppendLine("#endregion");
+    }
+    private static void GenerateAsyncMethods(string taskType, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string methodTemplateDecl)
+    {
+        sb.AppendLine($$"""
+        [PureAttribute]
+        [GeneratedCodeAttribute("{{nameof(ResultTryRecoverExecutor)}}", "1.0.0.0")]
+        public static async {{taskType}}<{{resultTypeDef}}> TryRecover{{methodTemplateDecl}}(this {{taskType}}<{{resultTypeDef}}> resultTask, Func<Error, {{resultTypeDef}}> recover)
+        {
+            var result = await resultTask.ConfigureAwait(false);
+            return result.State switch
+            {
+                ResultState.Success => ({{resultTypeDef}})result.Value,
+                ResultState.Error => recover(result.Error!),
+                _ => throw new ResultNotInitializedException(nameof(resultTask))
+            };
+        }
+        """);
+        sb.AppendLine($$"""
+        [PureAttribute]
+        [GeneratedCodeAttribute("{{nameof(ResultTryRecoverExecutor)}}", "1.0.0.0")]
+        public static async {{taskType}}<{{resultTypeDef}}> TryRecover{{methodTemplateDecl}}(this {{resultTypeDef}} result, Func<Error, {{taskType}}<{{resultTypeDef}}>> recover)
+        {
+            return result.State switch
+            {
+                ResultState.Success => ({{resultTypeDef}})result.Value,
+                ResultState.Error => await recover(result.Error!).ConfigureAwait(false),
+                _ => throw new ResultNotInitializedException(nameof(result))
+            };
+        }
+        """);
+        sb.AppendLine($$"""
+        [PureAttribute]
+        [GeneratedCodeAttribute("{{nameof(ResultTryRecoverExecutor)}}", "1.0.0.0")]
+        public static async {{taskType}}<{{resultTypeDef}}> TryRecover{{methodTemplateDecl}}(this {{taskType}}<{{resultTypeDef}}> resultTask, Func<Error, {{taskType}}<{{resultTypeDef}}>> recover)
+        {
+            var result = await resultTask.ConfigureAwait(false);
+            return result.State switch
+            {
+                ResultState.Success => ({{resultTypeDef}})result.Value,
+                ResultState.Error => await recover(result.Error!).ConfigureAwait(false),
+                _ => throw new ResultNotInitializedException(nameof(resultTask))
+            };
+        }
+        """);
+    }
+}