[deodad]

Motivation

Native apps on macOS and iOS, and Swift servers on Linux, cannot use ondine/compiler/wasm without a JavaScript engine. iOS allows no JIT, so these apps need a WebAssembly interpreter and a wrapper for the module's ABI. Each app now writes and maintains its own wrapper.

Changes

• Adds Package.swift at the repository root with the Ondine library under swift/. It runs a caller-supplied module in WasmKit 0.4.
• Ondine.Compiler(module:) takes one module: all.generated.wasm for every diagram type, or the module of one type, which renders only that type.
• Ondine.Options has the fields of render.Options and sends the same JSON. A fuel budget stops a pathological source with RenderError.fuelExhausted. Options.defaultFuel is one billion instructions, about one second in an optimized build, and callers can raise it.
• Ondine.RenderError.diagnostic carries the code, line, column, snippet, and message of RenderError. After a trap, the next render uses a fresh instance.
• Compiler is Sendable, and a lock serializes its renders.
• Adds a Swift job to the Verify workflow, the Swift Package guide, and a changeset.

Example

import Ondine

// Renders with all.generated.wasm from the npm package
let compiler = try Ondine.Compiler(module: Data(contentsOf: url))
let rendered = try compiler.render("flowchart LR\n  A --> B", options: .init(maxWidth: 640))
print(rendered.type, rendered.width, rendered.svg.prefix(4)) // flowchart 160.0 <svg

Validation

swift test passes with Swift 6.4.2 and in the swift:6.3-noble container (8 tests). Diagnostics, links, and widths in the tests match ondine/compiler/wasm for the same source and modules. Every sample in test/vectors/samples.json renders within ten million fuel, and one billion fuel runs out in 0.6 s in a release build. pnpm check and pnpm check:types pass.

Open Question

Should the package stay in this repository, with callers copying the .wasm from the npm package, or move to a separate repository such as ondine-swift? Tagged releases there could bundle the module as a resource, so Swift apps add one dependency and SwiftPM pins versions (this repository has no semver tags). The in-repo package needs no release process, while a separate repository must publish a release for each ondine version.