# YueScript

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Yuescript is a Moonscript dialect. It is derived from [Moonscript language](https://github.com/leafo/moonscript) 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](https://github.com/leafo/lapis) and run a few business web sites like [itch.io](https://itch.io) and [streak.club](https://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.



## Features

* No other dependencies needed except 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, backcall operator, Javascript-like export syntax and etc.
* See other details in the [changelog](./CHANGELOG.md).



## Installation & Usage

* **Lua Module**

  Build `yue.so` file with

```sh
> 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](https://luarocks.org), a package manager for Lua modules. Then install it as a Lua module with

```sh
> luarocks install yuescript
```

  Then require the Yuescript module in Lua:

```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:
```sh
> make install
```

  Build Yuescript tool without macro feature:
```sh
> make install NO_MACRO=true
```

  Build Yuescript tool without built-in Lua binary:
```sh
> make install NO_LUA=true
```

  Use Yuescript tool with:

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

   -h       Print this message
   -e str   Execute a file or raw codes
   -t path  Specify where to place compiled files
   -o file  Write output to file
   -s       Use spaces in generated codes instead of tabs
   -m       Generate minified codes
   -p       Write output to standard out
   -b       Dump compile time (doesn't write output)
   -l       Write line numbers from source codes
   -v       Print version
   --       Read from standard in, print to standard out
            (Must be first and only argument)

   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](https://github.com/pigpigyyy/Yuescript-vim)



## License

MIT