HyperCast 0.0.1

HyperCast

TryParse hands back a bool and a shrug. These doors hand back a native discriminated union — the value, or Empty/Malformed/OutOfRange plus the exact byte span that offended — and an unhandled case is a compile error, not a review nit.

Allocation-free scalar casts — booleans, the full integer family, reals, UUIDs, temporals — as source-generated [LibraryImport] P/Invoke straight into the native libhypercast Rust core. No runtime bridge, no reflection anywhere in the assembly. .NET 11 is the floor deliberately: Verdict<T> is a real [Union], and CS8509 (non-exhaustive switch) is elevated to an error, so a missing disposition fails the build — the entire point of returning a union instead of throwing.

var message = Cast.Int32("(1,234)", NumFormat.From(culture)) switch
{
    Success<int> s => $"got {s.Value}",                  // -1234, accounting negative
    Fault f => $"{f.Reason} at byte {f.Offset}",         // no third case: the compiler checked
};

Door names mirror the native ABI (Int32, Double, Timestamp, …) so the polyglot surface reads identically across bindings. Culture never lives in the core — NumFormat.From(CultureInfo) bridges .NET's culture machinery to the caller-declared format the native side actually reads. .NET-flavored fidelity, stated honestly: DateTimeOffset/TimeOnly/TimeSpan resolve to 100 ns ticks, so sub-tick nanoseconds truncate (the core carries full nanosecond fidelity; .NET's clock types don't).

Why not the BCL's own TryParse family?

1. The error story is data, not archaeology — a closed reason plus the offending span, against the BCL's bare false.

2. The vocabulary untrusted sources actually send — twenty boolean lexemes, accounting parentheses, radix prefixes, all five Guid formats plus urn:uuid: prefixes, protobuf JSON durations — much of it grammar the BCL has no knob for at any price.

3. One engine across a polyglot system — the same Rust core, bit-for-bit verdicts, proven by the shared conformance corpus every binding replays (all 28 of this binding's tests include the full twelve-file corpus through real P/Invoke).

4. Not slower — mostly faster. BenchmarkDotNet, [MemoryDiagnoser], lenience matched where the BCL has the knob, FFI crossing and UTF-16→UTF-8 transcode included in every HyperCast number; zero managed allocation on every row, both sides (linux-arm64, .NET 11 preview):

   Door	HyperCast	BCL	Verdict
   Cast.Timestamp vs DateTimeOffset.TryParse	71.0 ns	285.6 ns	4.0x faster
   Cast.Duration vs TimeSpan.TryParse	64.1 ns	143.0 ns	2.2x faster
   Cast.Double vs double.TryParse	50.4 ns	69.8 ns	1.4x faster
   Cast.Uuid vs Guid.TryParse	54.8 ns	51.9 ns	wash — while also taking N/B/P/X and urn:uuid:
   Cast.Int32 (grouped) vs int.TryParse	64.5 ns	54.0 ns	1.2x slower — the crossing tax, paid honestly
   Cast.Boolean vs bool.TryParse	18.5 ns	JIT-folded	honest loss — the twenty-lexeme vocabulary is why anyone calls this door
   Cast.DateTime (1/7/2026 3:04 PM) vs DateTime.TryParse (en-US)	61.2 ns	222.9 ns	3.6x faster
   Cast.Date (declared order) vs DateOnly.TryParse (en-US)	33.7 ns	132.3 ns	3.9x faster
   Cast.Double (eurozone) vs double.TryParse (de-DE)	98.7 ns	65.9 ns	1.5x slower — see below

   Reproduce: dotnet run -c Release --project HyperCast.Benchmarks.

   Separator detection is nearly free: NumFormat.Detect on 1.234.567,89 costs 104.4 ns against 98.7 ns for the same text under a declared eurozone format — ~6 ns for resolving the ./, roles structurally instead of being told them.

The honest trade-off: the eurozone double row is a real loss — double.TryParse under de-DE beats this door by ~33 ns, because non-invariant separators take the door's normalize-then-parse path rather than its invariant fast lane. And it's a native dependency (shipped per-RID inside the package) with a ~15–65 ns FFI crossing on every call. For plain invariant integers the BCL is already excellent; these doors earn their keep on the culture-machinery parsers, the closed error contract, and cross-language agreement.

AOT

IsAotCompatible is asserted and the analyzers fail the build on violations; the HyperCast.AotSmokeTest project publishes under PublishAot into a genuine native binary that runs every door — proven, not configured.

WebAssembly (Blazor)

One compiled assembly covers browser-wasm too — every native entry point is declared twice ("hypercast" for dlopen platforms, "*" for the statically-linked wasm module), sharing the same EntryPoint, with OperatingSystem.IsBrowser() picked at the call site and constant-folded by the linker. CI builds the wasm32-unknown-emscripten staticlib on every PR; the release pack stages it under runtimes/browser-wasm/nativeassets/.

Install

Not on nuget.org yet — the release pipeline is staged (.github/workflows/release.yml, Trusted Publishing pending) and the package ships with the first coordinated tag as HyperCast, with per-RID natives under runtimes/ and this README inside the package. Until then: clone the repo, cargo build --release in rust/, and reference csharp/HyperCast/HyperCast.csproj — the csproj stages the fresh native build into the output automatically.

See the repo root README for the full door table, the receipts, and the state of every other language binding.