ZeroAlloc.Specification
ZeroAlloc.Specification is a source-generated, zero-allocation implementation of the Specification pattern for .NET 8+.
Why ZeroAlloc.Specification?
The classic DDD Specification pattern allocates heap objects on every composition — And, Or, and Not return new wrapper class instances, and delegate-based predicates create closures. In hot paths this adds GC pressure.
ZeroAlloc.Specification uses a Roslyn incremental source generator to emit And<TOther>(), Or<TOther>(), and Not() methods directly onto your spec struct. Composed types are concrete readonly struct types — no heap allocation, no closures.
Key Properties
- Zero allocations — composed specs are structs, not classes
- EF Core compatible — every spec exposes
ToExpression()returningExpression<Func<T, bool>> - Compile-time safety — ZA001–ZA005 diagnostics enforce correct usage
- Familiar API — fluent (
.And(),.Or(),.Not()) and static builder (Spec.And(),Spec.Or(),Spec.Not()) - .NET 8+ — uses C# 12 features throughout
Packages
| Package | Purpose |
|---|---|
ZeroAlloc.Specification | Core interfaces, combinator structs and the bundled source generator |
ZeroAlloc.Specification.Generator | Standalone source generator, kept for backwards compatibility. New consumers reference only ZeroAlloc.Specification |
