@pyreon/native-runtime-swift

PRIVATE / EXPERIMENTAL. SwiftPM package that compiler-emitted Swift code links against on iOS. Phase 0 scaffold; see native-platforms-phase0-roadmap.md PR 1 for scope + acceptance criteria.

What lives here

Four Swift source files under Sources/PyreonRuntime/:

| File | Purpose | Status | |---|---|---| | PyreonTokens.swift | Design-system token tables (spacing, colors, typography). Compiler emits the real table in PR 7a alongside this stub. | Stub | | PyreonReactivity.swift | Adapter helpers between Pyreon's signal()/computed()/effect() and SwiftUI's @State/computed properties/.onChange(of:). Intentionally near-empty — SwiftUI's primitives ARE the reactive primitives; the compiler emits onto them directly. | Stub | | PyreonViewModifier.swift | PyreonStylable marker protocol for the styler emitter's output (PR 7b). | Stub | | PyreonStorage.swift | @PyreonAppStorage<T: Codable> property wrapper + PyreonStorage.{read,write,remove,decodeOrDefault} helpers. Real implementation — collapses the 14-line Codable-Data bridge the compiler currently emits inline to one line at the call site. | Real |

The first three carry the FUTURE API surface (namespace + placeholder symbol) so downstream PRs reference the right shape early without blocking on full implementation. PyreonStorage.swift is the first module with real, exercised behaviour — Codable-aware UserDefaults persistence.

PyreonStorage — Codable @AppStorage in one line

@PyreonAppStorage is a property wrapper that extends SwiftUI's @AppStorage to any Codable type. SwiftUI's stock @AppStorage only natively persists primitives (String, Int, Double, Bool, URL, Data, RawRepresentable). Codable arrays + structs need a hand-written Data bridge — 14 lines per slot. @PyreonAppStorage collapses it to one.

import PyreonRuntime

struct Todo: Codable { var id: Int; var text: String; var done: Bool }

struct TodoApp: View {
    @PyreonAppStorage("todos") private var todos: [Todo] = []
    // Same Binding<[Todo]> projection via $todos as @AppStorage.

    var body: some View {
        List(todos, id: \.id) { todo in
            Text(todo.text)
        }
    }
}

Persistence: UserDefaults via JSONEncoder/JSONDecoder. Identical durability + sync semantics to stock @AppStorage(Data). Failure semantics: silent fallback to default on decode failure, silent drop on encode failure — matches web @pyreon/storage's localStorage behaviour for corruption + quota errors. For explicit error handling outside View contexts: PyreonStorage.read(_:key:) / .write(_:key:) throw on failure.

Compiler interaction. The PMTC compiler currently emits the verbose 14-line inline bridge for every useStorage<T>('key', default) source call (per G5 + the Phase 2 Codable-Data PR). The next compiler-emit pass simplification will detect that pattern and emit the one-liner @PyreonAppStorage form instead — same persistence, dramatically simpler emit. Until that emit change lands, this property wrapper is also usable by hand-written SwiftUI code; both shapes back onto the same UserDefaults key, so they're interchangeable per-callsite.

Smoke tests

Tests/PyreonRuntimeTests/PyreonRuntimeTests.swift exercises every public symbol — proves the package builds, links, and tests cleanly. Real functional tests land per-feature alongside the implementations.

Build / test locally

Requires macOS with Xcode 15+ (Swift 5.9, iOS 17 target).

cd packages/native/runtime-swift
swift build
swift test

The npm scripts gracefully skip when swift isn't on PATH (Linux dev machines, CI runners without the Swift toolchain), so bun run --filter='*' test from the repo root doesn't break on cross-platform setups.

Why so empty?

Per the PMTC strategic plan (#764) and the Phase 0 roadmap (#797):

SwiftUI's @State IS the reactive primitive — Pyreon doesn't ship its own observable wrapper layer in production. The compiler emits onto SwiftUI's primitives directly. The runtime exists only for the FEW cases where the structural mapping needs a small helper (effect-with-dep-list tracking, signal-to-Combine bridging for legacy consumers).

The Phase 0 risk register flags: if this package grows past ~500 LOC of Swift, that's a signal the compiler emit shape is wrong and we should regroup. Current size: ~280 LOC (~80 stubs + ~200 real PyreonStorage).

Phase 0 dependencies

This package is the foundation for PRs 2, 3, 4, 7a, 7b, 7c, 8 per the roadmap. Every PR that touches iOS output needs this package to exist.

Privacy

Marked "private": true; not published to npm. Internal-only until PMTC reaches a state worth publishing.