ZeroAlloc.Specification.Generator 1.0.1

dotnet add package ZeroAlloc.Specification.Generator --version 1.0.1

NuGet\Install-Package ZeroAlloc.Specification.Generator -Version 1.0.1

This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.

<PackageReference Include="ZeroAlloc.Specification.Generator" Version="1.0.1">
  <PrivateAssets>all</PrivateAssets>
  <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
</PackageReference>

For projects that support PackageReference, copy this XML node into the project file to reference the package.

<PackageVersion Include="ZeroAlloc.Specification.Generator" Version="1.0.1" />
                    

                            Directory.Packages.props

<PackageReference Include="ZeroAlloc.Specification.Generator">
  <PrivateAssets>all</PrivateAssets>
  <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
</PackageReference>
                    

                            Project file

For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package.

paket add ZeroAlloc.Specification.Generator --version 1.0.1

The NuGet Team does not provide support for this client. Please contact its maintainers for support.

#r "nuget: ZeroAlloc.Specification.Generator, 1.0.1"

#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.

#:package ZeroAlloc.Specification.Generator@1.0.1

#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package.

#addin nuget:?package=ZeroAlloc.Specification.Generator&version=1.0.1
                    

                            Install as a Cake Addin

#tool nuget:?package=ZeroAlloc.Specification.Generator&version=1.0.1
                    

                            Install as a Cake Tool

The NuGet Team does not provide support for this client. Please contact its maintainers for support.

ZeroAlloc.Specification

Source-generated, zero-allocation specification pattern for .NET 8+.

Multiple packages in this family — see Documentation or NuGet for the full list.

Install

The source generator is bundled into the main package — a single PackageReference is all you need:

dotnet add package ZeroAlloc.Specification

The standalone ZeroAlloc.Specification.Generator package is still published for backwards compatibility with existing direct PackageReferences, but new consumers should reference only ZeroAlloc.Specification.

Example

[Specification]
public readonly partial struct ActiveUserSpec : ISpecification<User>
{
    public bool IsSatisfiedBy(User user) => user.IsActive;
    public Expression<Func<User, bool>> ToExpression() => u => u.IsActive;
}

[Specification]
public readonly partial struct PremiumUserSpec : ISpecification<User>
{
    private readonly decimal _minSpend;
    public PremiumUserSpec(decimal minSpend) => _minSpend = minSpend;

    public bool IsSatisfiedBy(User user) => user.TotalSpend >= _minSpend;
    public Expression<Func<User, bool>> ToExpression()
    {
        var min = _minSpend;
        return u => u.TotalSpend >= min;
    }
}

// Fluent composition — zero allocation
var spec = new ActiveUserSpec().And(new PremiumUserSpec(1000m));

// In-memory
bool result = spec.IsSatisfiedBy(user);

// EF Core — translates to SQL
var users = await dbContext.Users.Where(spec.ToExpression()).ToListAsync();

Features

Zero allocations — composed specs are readonly struct values, not heap objects
EF Core compatible — every spec exposes ToExpression() returning Expression<Func<T, bool>>
Source-generated fluent API — And<TOther>(), Or<TOther>(), Not() added by Roslyn generator
Static builder — Spec.And(), Spec.Or(), Spec.Not() for explicit type arguments
Compile-time safety — ZA001–ZA004 diagnostics enforce correct partial struct usage
.NET 8+, C# 12

Documentation

Page	Description
Introduction	What it is and why it exists
Getting Started	Install and first specification in 5 minutes
Core Concepts	ISpecification<T>, structs, stateful vs stateless
Fluent API	Generated And/Or/Not methods
Static Builder	Spec.And/Or/Not
Expression Composition	ToExpression() and EF Core translation
Diagnostics	ZA001–ZA004 compile-time errors and fixes
Generator Internals	How the Roslyn generator works
Performance	Allocation comparison and benchmarks
Cookbook: EF Core Repository	Repository pattern integration
Cookbook: Combining Specs	Complex compositions
Cookbook: Stateless Caching	Cache expression trees for stateless specs

License

MIT — see LICENSE.

There are no supported framework assets in this package.

Learn more about Target Frameworks and .NET Standard.

This package has no dependencies.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version	Downloads	Last Updated
1.0.1	86	5/4/2026
0.1.0	116	3/18/2026