YueScript

YueScript is a MoonScript dialect. It is derived from MoonScript language 0.5.0 and continuously adopting new features to be more up to date.

MoonScript is a language that compiles to Lua. Since original MoonScript has been used to write web framework lapis and run a few business web sites like itch.io and streak.club with some large code bases. The original language is getting too hard to adopt new features for those may break the stablility for existing applications.

So YueScript is a new code base for pushing the language to go forward and being a playground to try introducing new language syntax or programing paradigms to make MoonScript language more expressive and productive.

Yue (月) is the name of moon in Chinese and it's pronounced as [jyɛ].

About Dora SSR

YueScript is being developed and maintained alongside the open-source game engine Dora SSR. It has been used to create engine tools, game demos and prototypes, validating its capabilities in real-world scenarios while enhancing the Dora SSR development experience.

Features

• Based on modified parserlib library from Achilleas Margaritis with some performance enhancement. lpeg library is no longer needed.
• Written in C++17.
• Support most of the features from MoonScript language. Generate Lua codes in the same way like the original compiler.
• Reserve line numbers from source file in the compiled Lua codes to help debugging.
• More features like macro, existential operator, pipe operator, Javascript-like export syntax and etc.
• See other details in the changelog. Find document here.

Installation & Usage

• Lua Module

  Build yue.so file with

> make shared LUAI=/usr/local/include/lua LUAL=/usr/local/lib/lua

  Then get the binary file from path bin/shared/yue.so.

  Or you can install luarocks, a package manager for Lua modules. Then install it as a Lua module with

> luarocks install yuescript

  Then require the YueScript module in Lua:

require("yue")("main") -- require `main.yue`

local yue = require("yue")
local codes, err, globals = yue.to_lua([[
f = -> print "hello world"
f!
]],{
  implicit_return_root = true,
  reserve_line_number = true,
  lint_global = true
})

• Binary Tool

  Clone this repo, then build and install executable with:

> make install

  Build YueScript tool without macro feature:

> make install NO_MACRO=true

  Build YueScript tool without built-in Lua binary:

> make install NO_LUA=true

  Use YueScript tool with:

> yue -h
Usage: yue [options|files|directories] ...

   -h       Print this message
   -e str   Execute a file or raw codes
   -m       Generate minified codes
   -r       Rewrite output to match original line numbers
   -t path  Specify where to place compiled files
   -o file  Write output to file
   -s       Use spaces in generated codes instead of tabs
   -p       Write output to standard out
   -b       Dump compile time (does not write output)
   -g       Dump global variables used in NAME LINE COLUMN
   -l       Write line numbers from source codes
   -j       Disable implicit return at end of file
   -c       Reserve comments before statement from source codes
   -w path  Watch changes and compile every file under directory
   -v       Print version
   --       Read from standard in, print to standard out
            (Must be first and only argument)

   --target=version  Specify the Lua version that codes will be generated to
                     (version can only be 5.1, 5.2, 5.3 or 5.4)
   --path=path_str   Append an extra Lua search path string to package.path

   Execute without options to enter REPL, type symbol '$'
   in a single line to start/stop multi-line mode

  Use cases:
  Recursively compile every YueScript file with extension .yue under current path: yue .
  Compile and save results to a target path: yue -t /target/path/ .
  Compile and reserve debug info: yue -l .
  Compile and generate minified codes: yue -m .
  Execute raw codes: yue -e 'print 123'
  Execute a YueScript file: yue -e main.yue

Editor Support

• Vim
• ZeroBraneStudio (Syntax highlighting)
• Visual Studio Code

License

MIT