CRC32 host mappings

lib/checksum.CRC32IEEE computes the ZIP/IEEE CRC-32 of the logical byte slice. Nil and empty inputs return zero; bytes outside its length are ignored, inputs stay unchanged, and results retain all unsigned 32 bits. It is a checksum and provides no cryptographic authentication.

Target/entry	Implementation	Dependency
Go	hash/crc32.ChecksumIEEE	Standard library
Java	java.util.zip.CRC32	JDK standard library
Python	zlib.crc32	Standard library
TypeScript Node executable, conformance, or Node library entry	node:zlib.crc32	Node standard library
C#	System.IO.Hashing.Crc32.HashToUInt32(ReadOnlySpan<byte>)	Official Microsoft NuGet package, pinned to 8.0.0
TypeScript browser or portable library entry	Slicing-by-8 IEEE implementation	No standard browser CRC API
C	Slicing-by-8 IEEE implementation	No standard C CRC API
Rust	crc32fast::hash with runtime CPU detection	Cargo crate, pinned to 1.5.2
Swift	crc32 via the native zlib shim	System zlib; Swift has no standard CRC32 API

Host APIs choose their own native implementation, vectorization, and hardware acceleration. Delegation permits host optimizations; Goalchemy does not guarantee that any particular CPU instruction or accelerated path runs.

TypeScript entries

Generated executables and the conformance harness install the Node checksum adapter automatically. Generated libraries expose conditional package exports: Node selects dist/node.js, and browser/default consumers select dist/main.js. Import the installed package by name for automatic selection, or use dist/node.js directly in Node. Direct dist/main.js imports intentionally select the portable implementation, including when imported in Node. The Node library entry installs only the checksum adapter; it does not install executable stdout, stderr, seed, or process-exit behavior. Portable dependency graphs contain no Node imports, Buffer, or process references.

The supported Node minimum remains 22.6; the standard zlib.crc32 API has existed since 22.2. Calls pass a Uint8Array view of the logical bytes, including the backing view’s byte offset; they never encode bytes as text.

C# dependency and consumers

System.IO.Hashing 8.0.0 is a first-party Microsoft package, separate from the shared .NET 8 runtime. CRC-using generated projects include an exact PackageReference, packages.lock.json with its NuGet content hash, and locked restore. run.sh keeps the direct C# compiler path, restores the package, references its .NET 8 DLL, and copies that DLL beside the executable. dotnet run --project main.csproj uses normal SDK dependency resolution. Programs that do not link CRC keep their existing build script and have no checksum package dependency.

For a generated library, use a ProjectReference to main.csproj so normal NuGet/SDK resolution carries the package transitively into the consumer’s output. Consumers that reference only lib/main.dll must also reference System.IO.Hashing 8.0.0 and deploy its DLL. build.sh produces the generated library; deployment of an assembly alone does not install its dependencies.

Repository conformance and tests compile the complete C# runtime, so their builds require the package even when an individual test exercises another capability. scripts/ci-bootstrap.sh prewarms the locked checksum project; targets/csharp/tests/checksum-dependencies.sh repeats locked restore and returns the package DLL used by direct compiler harnesses.

Rust dependency

Generated native Cargo projects and the conformance harness pin crc32fast 1.5.2. Its default std feature remains enabled so it can detect CPU features and select an accelerated IEEE CRC32 implementation when supported. The runtime hashes the logical byte slice directly without copying or mutating its backing storage. Empty and nil slices return zero. The harness lockfile records the crate checksum and CI prefetches and builds that locked graph before running contracts.

Native Cargo output includes this direct dependency; programs that use only subset logic keep their existing standard-library rustc path. Structural standard-library-only byte and scheduler probes omit production checksum, crypto, encoding, HTTP, and callback modules; CRC behavior is checked separately through the Cargo harness and generated executable/library consumers.