PureDartLua

• PureDartLua
  • Run Scripts
  • DOT File Visualizer
  • Features
• Work In Progress!
  • Missing Lua Lang Support
  • Extra Goals

This is a custom a custom Lua 5.5 interpretter and evaluator written from scratch in pure Dart. I wrote this as a part of a series of learning exercises on how to write my own compilers and programming languages.

Run Scripts

This package exports a full fledged library and a simple executable for running lua scripts.

To get started, run Hello World.

dart bin/main.dart -e test/assets/hello_world.lua

DOT File Visualizer

Run

dart bin/main.dart -v my_script.lua

The DOT file will be embedded in an HTML page my_script.lua.html.

Features

• Command Line Interface (cli).
• MIT Licensed.
• No FFI or extra dependencies.
• DOT file visualiser.
• Autodoc API so your own libs can generate docs to share with your consumers.
• Register your own custom runtime userdata.
• Emit custom warnings, diagnostic info, or errors.
• Lua 5.5 compliant.
  • See this section for remaining issues.
• Parser, Evaluator, Interpreter classes extensible and modifiable.
• Truthy and Native2Lua Dart class extensions for convenient bridge between userdata and lua types.
• Function builder API to conveniently build complex lua functions.
• Standard lua runtime libs (partial implementation).
  • strings
  • include
  • ipairs
  • pairs
  • table
  • print
  • math

Because this is a pure dart lua interpreter, it is not expected to be as fast as the C ffi alternative libs for Dart. However, it is much more programmer friendly!

Work In Progress!

I am using this in my own projects and as such I have not created tutorials or get started guides. I will get around to that when I can!

Missing Lua Lang Support

Here's what's left to be compliant with the Lua 5.5 specification:

• Missing a semantics pass for goto and ::label:: statements.
• Metamethods.
  • Particularly there is no support for metamethods except for ___call.
  • But metamethods are just function objects with a few places that lua calls as defined.
• <const> is not added.
• Coroutines are not added.
• I may have missed one variant of function declarations.

Extra Goals

• Semantics: code path type unification.
  • return statements could have the function's final type identified.
  • Nondeterministic functions should be identified as such.
    • This would allow invariant code paths to be protomoted to constant value generation.