flark #

The Markdown editing kernel behind flark_flutter and flark_fleury. The Markdown source is the document: nothing is converted to a rich-text model and back.

Every edit re-parses the whole document with unmodified comrak, CommonMark 0.31.2 and GitHub Flavored Markdown. The kernel projects that parse into rows that hide syntax outside the caret's context, keeps the caret on legal source offsets, and edits through a closed set of commands, so what users type is exactly what is saved.

Most apps use a host package. Use flark directly to write a host, or to edit and read Markdown without a UI:

import 'package:flark/flark.dart';
import 'package:flark/session.dart';

final session = FlarkSession(markdown: 'Plain ');
await session.ready;
session.command(const SetSelection(6, 6));
session.command(const ToggleStyle(Style.strong));
for (final character in 'bold words'.split('')) {
  session.command(InsertText(character));
}
print(session.state.markdown); // Plain **bold words**

Status #

0.5 is a preview. The parser's HTML output matches the CommonMark and GFM spec suites apart from a short list of registered comrak deviations, and the kernel is covered by generated command sequences with invariants on every step. Platform qualification is uneven:

Screen-reader support (VoiceOver, TalkBack) has not been qualified.

The parser library #

On Android, iOS, macOS, Linux and Windows the parser is a native library. The package's build hook downloads the library for the target you build, from this repository's GitHub release, checks it against the SHA-256 pinned in hook/prebuilt.json, and caches it in the project's .dart_tool, so rebuilds of that project reuse it. A fresh clone, a CI run or flutter clean downloads it again. To build without network access, fetch the files once and point the hook at them:

hooks:
  user_defines:
    flark:
      prebuilt_dir: /path/to/flark_parse

The directory holds <target triple>/<library>, for example aarch64-apple-darwin/libflark_parse.dylib. The release names its assets <target triple>-<library> (aarch64-apple-darwin-libflark_parse.dylib), so save each one under its triple's directory with the library's own name, and check it against the SHA-256 in hook/prebuilt.json. In a checkout of this repository the hook builds the parser from native/flark_parse with Rust instead.

On the web the parser is the Wasm module bundled in the package; nothing is downloaded.

License #

MIT. The parser links comrak and other Rust crates; their licenses are in THIRD_PARTY_NOTICES.md.