Hydro-SDK

Author Flutter experiences in Typescript. No native bridge, no V8. Just Dart. From runtime to virtual machine.

Sponsored by

Possibly you! See sponsoring Hydro-SDK

Documentation and Tutorials

https://hydro-sdk.io/

Features

Hot Reload, Incremental Compilation

Function Maps

Roadmap

Hydro-SDK is a software development kit (SDK) enabling Flutter developers to write portions of their app (or their entire app) using Typescript. It is a project with one large, ambitious goal. "Become React Native for Flutter". It aims to do that by:

1. Decoupling the API surface of Flutter from the Dart programming language.
2. Decoupling the development time experience of Flutter from the Dart programming language.
3. Providing first-class support for over-the-air distribution of code.
4. Providing an ecosystem of packages from pub.dev, automatically projected to supported languages and published to other package systems.

Hydro-SDK is currently only suitable for simple content. A few dozen Flutter widgets are supported. Content built with Hydro-SDK can be updated over the air using Hydro-SDK's built-in codepush. Content can be authored in a similar manner as in Dart with hot-reload and limited IDE debugging support.

Near Term

API Support

Continue expanding available Dart and Flutter APIs with automatic language projection (ALP) using Structured Wrapper and Interface generator for Dart (SWID). This effort is where the overwhelming amount of focus currently is. Having a stable and high quality ALP will allow for the re-use of existing packages from pub.dev in Typescript. This will also allow for expanding support for authoring Hydro-SDK content to other programming languages.

This work is tracked at a high-level in the Binding Generator project and in other sub-projects. This work is required to expand support for Flutter 2.8 (and 2.10) and is directly related to the following umbrella issues.

• ☂️ Support Flutter 2.8
• ☂️ Cables

Medium Term

Developer Ergonomics

Improving developer ergonomics with more affective testing workflows and support for Typescript language features like async / await interop with Dart. This is being scoped and tracked at a high level in umbrella issues.

• ☂️ Improved Test Ergonomics
• ☂️ Typescript 4

Performance

Establishing performance baselines through benchmarking. Some efforts to improve performance. This is being scoped and tracked at a high level in umbrella issues.

• ☂️ Optimizing Lua Compiler
• ☂️ Size Benchmarks
• ☂️ CPU and Memory Benchmarks

Long Term Projects

Developer Ergonomics

Lower the barrier to entry for developers with non-mobile backgrounds that are interested in trying out Flutter and Hydro-SDK.

• ☂️ Component Preview

Services

Registry

A closed-source component registry for first-class support for hosting and running over-the-air (OTA) update packages built using the open-source Hydro-SDK. This service is already live as a basic MVP.

Registry Value Adds

In the future, building paid features such as targeted distribution, analytics, feature flagging and logging directly into Registry are expected to be a viable path to monetization.

Language Support

Hydro-SDK is language agnostic. In the future, it should be possible to support authoring content in other programming languages to attract users from other ecosystems (Flixel, .NET, Xamarin).

Tier 1 (hot-reload, programmatic debugging, function maps)

• [✓] Typescript
  https://github.com/TypeScriptToLua/TypeScriptToLua

Tier 2 (hot-reload, programmatic debugging)

• [ ] Haxe
  https://github.com/HaxeFoundation/haxe
• [ ] C#
  https://github.com/yanghuan/CSharp.lua

Prior Art for Common Flutter Runtime

• Dartlua, Andre Lipke https://github.com/PixelToast/dartlua
• React Native, Facebook https://reactnative.dev/
• LuaViewSdk, Alibaba https://github.com/alibaba/LuaViewSDK
• ILRuntime, Ourpalm https://github.com/Ourpalm/ILRuntime
• Flutterscript, Charles Lowell https://github.com/cowboyd/flutterscript
• Lisp in Dart, Suzuki Hisao https://github.com/nukata/lisp-in-dart
• widget_extensions https://github.com/canewsin/widget_extensions
• xamarin.flutter https://github.com/adamped/xamarin.flutter

Prior Art for Structured Wrapper and Interface generator for Dart

• Dartle, https://docs.google.com/document/d/1Ei0ZIqdqNjxTHoGB3Ay6SWQg3DMSsKKWl70XoBUCFTA/edit
• Pigeon, https://github.com/flutter/packages/tree/master/packages/pigeon
• Djinni, https://github.com/dropbox/djinni
• Uniffi-rs, https://github.com/mozilla/uniffi-rs
• TS to CSharp, https://github.com/mono/TsToCSharp

Interesting Links and Resources

• John C. Reynolds, Definitional Interpreters for Higher-Order Programming Languages https://surface.syr.edu/cgi/viewcontent.cgi?article=1012&context=lcsmith_other
• Andrey Mokhov, Neil Mitchell, Simon Peyton Jones, Build Systems a la carte: Theory and Practice https://www.cambridge.org/core/journals/journal-of-functional-programming/article/build-systems-a-la-carte-theory-and-practice/097CE52C750E69BD16B78C318754C7A4
• Fabio Mascarenhas de Queiroz, Optimized Compilation of a Dynamic Language to a Managed Runtime Environment http://www.lua.inf.puc-rio.br/publications/mascarenhas09optimized.pdf
• Michael Schroder, Optimizing Lua Using Run-time Type Specialization https://www.complang.tuwien.ac.at/anton/praktika-fertig/schroeder/thesis.pdf
• Satoru Kawahara, Optimizing Lua VM Bytecode Using Global Dataflow Analysis https://nymphium.github.io/pdf/opeth_report.pdf
• Haichuan Wang, Compiler and Runtime Techniques for Optimizing Dynamic Scripting Languages https://www.ideals.illinois.edu/bitstream/handle/2142/78638/WANG-DISSERTATION-2015.pdf?sequence=1&isAllowed=y
• Kevin Williams, Jason McCandless, David Gregg, Dynamic Interpretation for Dynamic Scripting Languages https://sites.cs.ucsb.edu/~ckrintz/papers/TCD-CS-2009-37.pdf
• Dibyendu Majumdar, Ravi Lua 5.3 bytecode reference https://the-ravi-programming-language.readthedocs.io/en/latest/lua_bytecode_reference.html
• Kein-Hong Man, A No-Frills Introduction to Lua 5.1 VM Instructions http://luaforge.net/docman/83/98/ANoFrillsIntroToLua51VMInstructions.pdf
• Rust Programming Language Request for Comments 2603, Symbol Name Mangling https://github.com/rust-lang/rfcs/blob/master/text/2603-rust-symbol-name-mangling-v0.md
• Itanium C++ Application Binary Interface Specification https://itanium-cxx-abi.github.io/cxx-abi/abi.html
• Yan Dong Zonz, Wen Hui-chao, Exploration and practice of Flutter packet size management https://tech.meituan.com/2020/09/18/flutter-in-meituan.html
• Shangxian, Meituan takeaway Flutter dynamic practice https://tech.meituan.com/2020/06/23/meituan-flutter-flap.html
• Vyacheslav Egorov, 10 Years of Dart (Slides) https://mrale.ph/talks/vmil2020/