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Use when deciding which CSharpEssentials package to use — overview of all 20 packages organized by concern, the meta-package that bundles core functional modules, and a quick-reference table mapping problems to packages.
Codex または Claude でインストール この Prompt をコピーして Codex、Claude、または他のアシスタントに貼り付けると、Skill ページを確認してインストールできます。
SOC 職業分類に基づく
Use when representing optional values explicitly — Maybe<T> as a null-safe container, Maybe.From()/FromTry() for creation, HasValue/HasNoValue, Map/Bind chaining, TapNone for None-side effects, Match for consumption, and ToMaybeResult() to bridge into the Result pattern.
Use when handling operation outcomes without exceptions — Result and Result<T> for success/failure, railway-oriented chaining with Then/ThenAsync/Ensure, Match for consumption, and Result.And/Or for combining multiple results.
Use when composing business validation logic — define rules as classes, Func fields, or inline lambdas; combine with .And()/.Or()/.Linear()/.Next(); evaluate with RuleEngine.Evaluate(); branch with RuleEngine.If().
Use when modeling partial success — These<TError, TValue> holds Left (error only), Right (value only), or Both (error + value), enabling scenarios where a result can partially succeed while carrying warnings. Use FromResult to bridge from Result<T>, ToResult/ToResultLenient to bridge back, and Partition to split collections.
Use when you need testable time — IDateTimeProvider wraps clock access so production code uses DateTimeProvider while tests use the built-in FakeDateTimeProvider to freeze/advance/set the clock; also provides .ToDateOnly() and .ToTimeOnly() DateTime extension methods.
Use when adding cross-cutting pipeline behaviors to CQRS handlers — ValidationBehavior (CSharpEssentials.Validation, throws EnhancedValidationException), LoggingBehavior (ILoggableRequest), ExceptionHandlingBehavior (auto-converts exceptions to Result.Failure for Result-returning handlers), CachingBehavior (ICacheable with IDistributedCache), and TransactionScopeBehavior (ITransactionalRequest).
| name | csharpessentials-meta |
| description | Use when deciding which CSharpEssentials package to use — overview of all 20 packages organized by concern, the meta-package that bundles core functional modules, and a quick-reference table mapping problems to packages. |
CSharpEssentials is a modular .NET NuGet ecosystem. Each package is independent — take only what you need.
dotnet add package CSharpEssentials
# Includes: Results, Errors, Maybe, Any, Core, Enums
| Package | Install | Skill |
|---|---|---|
CSharpEssentials.Results | dotnet add package CSharpEssentials.Results | csharpessentials-results |
CSharpEssentials.Errors | dotnet add package CSharpEssentials.Errors | csharpessentials-errors |
CSharpEssentials.Maybe | dotnet add package CSharpEssentials.Maybe | csharpessentials-maybe |
CSharpEssentials.Any | dotnet add package CSharpEssentials.Any | csharpessentials-any |
CSharpEssentials.Core | dotnet add package CSharpEssentials.Core | csharpessentials-core |
CSharpEssentials.Enums | dotnet add package CSharpEssentials.Enums | csharpessentials-enums |
| Package | Install | Skill |
|---|---|---|
CSharpEssentials.Rules | dotnet add package CSharpEssentials.Rules | csharpessentials-rules |
CSharpEssentials.Validation | dotnet add package CSharpEssentials.Validation | csharpessentials-validation |
| Package | Install | Skill |
|---|---|---|
CSharpEssentials.Mediator | dotnet add package CSharpEssentials.Mediator | csharpessentials-mediator |
| Package | Install | Skill |
|---|---|---|
CSharpEssentials.Entity | dotnet add package CSharpEssentials.Entity | csharpessentials-entity |
CSharpEssentials.EntityFrameworkCore | dotnet add package CSharpEssentials.EntityFrameworkCore | csharpessentials-efcore |
| Package | Install | Skill |
|---|---|---|
CSharpEssentials.AspNetCore | dotnet add package CSharpEssentials.AspNetCore | csharpessentials-aspnetcore |
CSharpEssentials.Http | dotnet add package CSharpEssentials.Http | csharpessentials-http |
CSharpEssentials.Json | dotnet add package CSharpEssentials.Json | csharpessentials-json |
CSharpEssentials.RequestResponseLogging | dotnet add package CSharpEssentials.RequestResponseLogging | csharpessentials-logging |
CSharpEssentials.GcpSecretManager | dotnet add package CSharpEssentials.GcpSecretManager | csharpessentials-gcpsecretmanager |
| Package | Install | Skill |
|---|---|---|
CSharpEssentials.Resilience | dotnet add package CSharpEssentials.Resilience | csharpessentials-resilience |
| Package | Install | Skill |
|---|---|---|
CSharpEssentials.Time | dotnet add package CSharpEssentials.Time | csharpessentials-time |
CSharpEssentials.Clone | dotnet add package CSharpEssentials.Clone | csharpessentials-clone |
| Problem | Package |
|---|---|
| Return errors without exceptions | CSharpEssentials.Results + CSharpEssentials.Errors |
| Represent optional values (no null) | CSharpEssentials.Maybe |
| Return one of several distinct types | CSharpEssentials.Any |
| Compose business validation rules | CSharpEssentials.Rules |
Model-first validation returning Result<T> | CSharpEssentials.Validation |
| CQRS pipeline behaviors (validate, log, cache, transact) | CSharpEssentials.Mediator |
| DDD aggregate base class + domain events | CSharpEssentials.Entity |
| EF Core audit, slow queries, pagination | CSharpEssentials.EntityFrameworkCore |
| Map errors to HTTP ProblemDetails | CSharpEssentials.AspNetCore |
| HttpClient that returns Result | CSharpEssentials.Http |
| JSON serialization with string enums + polymorphism | CSharpEssentials.Json |
| Log request/response bodies | CSharpEssentials.RequestResponseLogging |
| Load secrets from GCP Secret Manager | CSharpEssentials.GcpSecretManager |
| Transient fault handling (retry, timeout, circuit breaker, fallback) | CSharpEssentials.Resilience |
| Testable time / freeze clock in tests | CSharpEssentials.Time |
| Deep-copy entity collections | CSharpEssentials.Clone |
| Fast enum-to-string (NativeAOT-safe) | CSharpEssentials.Enums |
| String case conversions, GUID utilities | CSharpEssentials.Core |
using CSharpEssentials.ResultPattern; // Result, Result<T>
using CSharpEssentials.Errors; // Error, ErrorType, ErrorMetadata
using CSharpEssentials.Maybe; // Maybe<T>
using CSharpEssentials.Any; // Any<T1,T2,...>
using CSharpEssentials.Core; // string/GUID/collection helpers
using CSharpEssentials.Enums; // [StringEnum]
using CSharpEssentials.Rules; // IRule<T>, RuleEngine
using CSharpEssentials.Validation; // Validator<T>, RuleContext<T>, IValidator<T>
using CSharpEssentials.Mediator; // ICacheable, ILoggableRequest, ITransactionalRequest
using CSharpEssentials.Entity; // EntityBase, SoftDeletableEntityBase
using CSharpEssentials.Entity.Interfaces; // IDomainEvent
using CSharpEssentials.EntityFrameworkCore; // interceptors, pagination
using CSharpEssentials.AspNetCore; // GlobalExceptionHandler, ResultEndpointFilter
using CSharpEssentials.Http; // HttpClientResultExtensions, HttpRequestBuilder
using CSharpEssentials.Resilience; // ResiliencePolicy, ResiliencePolicy<T>
using CSharpEssentials.Json; // JsonOptions, converters
using CSharpEssentials.RequestResponseLogging; // LoggingOptions, SkipLoggingAttributes
using CSharpEssentials.GcpSecretManager; // AddGcpSecretManager()
using CSharpEssentials.Time; // IDateTimeProvider, DateTimeProvider
using CSharpEssentials.Clone; // ICloneable<T>