extensions rework pt1

2026-07-13 22:20:47 +04:00
parent 46487a4794
commit 0e7986996f
30 changed files with 1476 additions and 160 deletions
@@ -0,0 +1,94 @@
+using System.Collections.Immutable;
+using System.Text;
+using Microsoft.CodeAnalysis;
+
+namespace Just.Railway.SourceGen.Executors.ResultExtensions;
+
+internal abstract class ResultExtensionsExecutor : IGeneratorExecutor
+{
+    public void Execute(IncrementalGeneratorPostInitializationContext context)
+    {
+        var methods = GenerateMethods();
+        var code = $$"""
+        #nullable enable
+        using System;
+        using System.Collections.Generic;
+        using System.Diagnostics.Contracts;
+        using System.CodeDom.Compiler;
+
+        namespace {{NamespaceName}};
+
+        public static partial class {{PartialClassName}}
+        {
+        {{methods}}
+        }
+        """;
+
+        context.AddSource($"{PartialClassName}.{ExtensionType}.g.cs", code);
+    }
+
+    private string GenerateMethods()
+    {
+        var sb = new StringBuilder();
+
+        GenerateHelperMethods(sb);
+        for (int i = 0; i <= Constants.MaxResultTupleSize; i++)
+        {
+            GenerateMethodsForArgCount(sb, argCount: i);
+        }
+
+        return sb.ToString();
+    }
+
+    protected static string GenerateTemplateDecl(ImmutableArray<string> templateArgNames) => templateArgNames.Length > 0
+        ? $"<{string.Join(", ", templateArgNames)}>"
+        : string.Empty;
+
+    protected static string GenerateResultTypeDef(ImmutableArray<string> templateArgNames) => templateArgNames.Length switch
+        {
+            0 => "Result",
+            1 => $"Result<{string.Join(", ", templateArgNames)}>",
+            _ => $"Result<({string.Join(", ", templateArgNames)})>",
+        };
+    protected static string JoinArguments(string arg1, string arg2) => (arg1, arg2) switch
+    {
+        ("", "") => "",
+        (string arg, "") => arg,
+        ("", string arg) => arg,
+        _ => $"{arg1}, {arg2}"
+    };
+
+    protected static string GenerateResultValueExpansion(ImmutableArray<string> templateArgNames)
+    {
+        string resultExpansion;
+
+        switch (templateArgNames.Length)
+        {
+            case 0:
+            resultExpansion = string.Empty;
+            break;
+
+            case 1:
+            resultExpansion = "result.Value";
+            break;
+
+            default:
+            var resultExpansionBuilder = new StringBuilder();
+            for (int i = 1; i <= templateArgNames.Length; i++)
+            {
+                resultExpansionBuilder.Append($"result.Value.Item{i}, ");
+            }
+            resultExpansionBuilder.Remove(resultExpansionBuilder.Length - 2, 2);
+            resultExpansion = resultExpansionBuilder.ToString();
+            break;
+        }
+
+        return resultExpansion;
+    }
+
+    protected abstract string ExtensionType { get; }
+    protected abstract string NamespaceName { get; }
+    protected abstract string PartialClassName { get; }
+    protected abstract void GenerateMethodsForArgCount(StringBuilder sb, int argCount);
+    protected virtual void GenerateHelperMethods(StringBuilder sb) {}
+}