Swift

IllusionMarkdown is MDI’s Swift Package Manager distribution. Its product and import module are both named MDI:

import MDI

Swift forwards parsing and rendering to the Rust mdi-core through a compact C ABI. It does not reimplement the grammar, so all bindings share the same syntax, document IR, diagnostics, and renderers.

Installation

Add MDI to your package dependencies, then add the MDI product to the target that uses it:

dependencies: [
    .package(url: "https://github.com/illusions-lab/MDI.git", from: "2.0.3"),
]

// In a target:
.product(name: "MDI", package: "MDI")

The binary package supports macOS 13+ and iOS 15+ on Apple Silicon and Intel simulators where applicable.

Parsing

MDI.parse(_:) returns the versioned, Rust-owned document IR:

let result = try MDI.parse("# 見出し\n\n{東京|とうきょう}で第^12^話")

print(result.irVersion)          // "1.0"
print(result.capabilities.mdi)   // true
print(result.diagnostics)

result.document is a lossless MDIJSONValue tree. Use pattern matching on .object, .array, .string, .number, .bool, and .null when consuming nodes. Source positions are UTF-8 byte offsets in MDISourceSpan.

Rendering and serialization

All renderers take MDI source text:

let html = try MDI.renderHTML("{東京|とうきょう} ^12^")
let mdi = try MDI.serialize("{東京|とうきょう} ^12^")
let text = try MDI.renderText("# Title")
let note = try MDI.renderTextFormat(
    "# Title\n\n{東京|とうきょう}",
    format: .note
)

let epub: Data = try MDI.renderEPUB("# Chapter")
let docx: Data = try MDI.renderDOCX("# Chapter")

MDITextFormat exposes the same six Rust-owned conventions as the other bindings: plain, ruby, narou, kakuyomu, aozora, and note. renderEPUB and renderDOCX return ZIP-based Data; write the data to a file with the appropriate extension.

Errors

Every public operation throws MDIError:

• MDIError.core reports a failure returned by the Rust core.
• MDIError.invalidWireFormat indicates an invalid or unsupported native response.

do {
    let html = try MDI.renderHTML(source)
    print(html)
} catch let error as MDIError {
    print(error.localizedDescription)
}

Development and releases

The repository’s swift/Package.swift is the local development package. CI builds an XCFramework, runs XCTest with a 95% line-coverage gate for swift/Sources/MDI, and uploads the report to Codecov. The release workflow creates a manifest pull request and publishes the approved artifact after that PR is merged. It uses GitHub Actions’ built-in token; no PAT or second repository is required.

Automatic warichu layout

Rust is the only splitting implementation. Layout uses two lines at half the body font size with zero line gap. The first fragment can use remaining body-line capacity; later fragments use full capacity. Capacity and widths are half-em units at note size, using character-width estimates rather than exact proportional-font balancing.

let fragments = try MDI.layoutWarichu(
    [.object(["type": .string("text"), "value": .string("一二三四五六")])],
    capacity: 4, firstCapacity: 2)

Results include lines, html, widths, overflow, hardBreakAfter and sources. Source paths are child indices relative to the input array; startUtf8 and endUtf8 are half-open byte offsets in visible leaf text. Indivisible group IDs keep clusters across formatting boundaries together. Ruby, tcy and no-break stay whole. Hard breaks are retained; automatic splits do not change canonical MDI or plain text. Static HTML/EPUB readers may reflow differently. DOCX uses native combination groups; XML and importer checks are not a claim of Microsoft Word rendering tests.