moonsharp-devs/moonsharp

An interpreter for the Lua language, written entirely in C# for the .NET, Mono, Xamarin and Unity3D platforms, including handy remote debugger facilities.

MoonSharp

http://www.moonsharp.org

A complete Lua solution written entirely in C# for the .NET, Mono, Xamarin and Unity3D platforms.

Features:

• 99% compatible with Lua 5.2 (with the only unsupported feature being weak tables support)
• Support for metalua style anonymous functions (lambda-style)
• Easy to use API
• Debugger support for Visual Studio Code (PCL targets not supported)
• Remote debugger accessible with a web browser and Flash (PCL targets not supported)
• Runs on .NET 3.5, .NET 4.x, .NET Core, Mono, Xamarin and Unity3D
• Runs on Ahead-of-time platforms like iOS
• Runs on IL2CPP converted code
• Runs on platforms requiring a .NET 4.x portable class library (e.g. Windows Phone)
• No external dependencies, implemented in as few targets as possible
• Easy and performant interop with CLR objects, with runtime code generation where supported
• Interop with methods, extension methods, overloads, fields, properties and indexers supported
• Support for the complete Lua standard library with very few exceptions (mostly located on the 'debug' module) and a few extensions (in the string library, mostly)
• Async methods for .NET 4.x targets
• Supports dumping/loading bytecode for obfuscation and quicker parsing at runtime
• An embedded JSON parser (with no dependencies) to convert between JSON and Lua tables
• Easy opt-out of Lua standard library modules to sandbox what scripts can access
• Easy to use error handling (script errors are exceptions)
• Support for coroutines, including invocation of coroutines as C# iterators
• REPL interpreter, plus facilities to easily implement your own REPL in few lines of code
• Complete XML help, and walkthroughs on http://www.moonsharp.org

For highlights on differences between MoonSharp and standard Lua, see http://www.moonsharp.org/moonluadifferences.html

Please see http://www.moonsharp.org for downloads, infos, tutorials, etc.

License

The program and libraries are released under a 3-clause BSD license - see the license section.

Parts of the string library are based on the KopiLua project (https://github.com/NLua/KopiLua). Debugger icons are from the Eclipse project (https://www.eclipse.org/).

Usage

Use of the library is easy as:

double MoonSharpFactorial()
{
	string script = @"    
		-- defines a factorial function
		function fact (n)
			if (n == 0) then
				return 1
			else
				return n*fact(n - 1)
			end
		end

	return fact(5)";

	DynValue res = Script.RunString(script);
	return res.Number;
}

For more in-depth tutorials, samples, etc. please refer to http://www.moonsharp.org/getting_started.html

moonsharp's Issues

Xml help to be completed

Module not found - Script run time error when using required in Lua script

Hi,

Please let me know how to resolve this error. I am new to Lua.

Thank you.

Regards,
Suresh

Grammar and Lexico tests not passing due to error message not matching.

Test blocks temporarily ignored.

Create debugger nuget package and release dlls in batch

Simplify method marshalling

• Improve CallbackFunction.FromMethodInfo
• Make StandardUserDataMethodDescriptor public
• Make StandardUserDataPropertyDecriptor public

Runtime error messages lack reference to sourcecode.

table.unpack raises IndexOutOfRangeException

See https://groups.google.com/forum/#!topic/moonsharp/LWu5NoPju2Y

String escape sequence \<CR> does not work.

Investigate standard on this.
However lua interpreter surely supports it - it is used in dungeon.lua files of Legend of Grimrock, for example.

MoonSharpValueToClrObject returns null for static userdata

Should return Type instead.

No value is indistiguishable from nil in most parts of code.

: calls should work as . calls on user data

Varargs not supported on main chunk

https://groups.google.com/forum/#!topic/moonsharp/LWu5NoPju2Y

8-queens problem crashes the interpreter

8 queens crashes:

N = 8

board = {}
for i = 1, N do
    board[i] = {}
    for j = 1, N do
    board[i][j] = false
    end
end

function Allowed( x, y )
    for i = 1, x-1 do
    if ( board[i][y] ) or ( i <= y and board[x-i][y-i] ) or ( y+i <= N and board[x-i][y+i] ) then 
        return false 
    end
    end     
    return true
end

function Find_Solution( x )
    for y = 1, N do
    if Allowed( x, y ) then 
        board[x][y] = true 
        if x == N or Find_Solution( x+1 ) then
        return true
        end
        board[x][y] = false          
    end     
    end
    return false
end

if Find_Solution( 1 ) then
    for i = 1, N do
    for j = 1, N do
        if board[i][j] then 
        print( 'Q' )
        else 
        print( 'x' )
        end
    end
    print( '|' )
    end
else
    print( 'NO!' )
end

Create portable class library version for .net 4.x

Tests must be done for Xamarin and Unity in Android and iOS.

Marshall Script and ScriptExecutionContext as first param

Assigning nil to a table field should delete it

In Lua 5.2, this code:

function showTable(t)
    for i, j in pairs(t) do
        print(j)
    end
end

tb = {}
tb["id"] = 3

print("Before:")
showTable(tb)

tb["id"] = nil

print("After:")
showTable(tb)
print("End")

outputs this:

Before:
3
After:
End

while in Moonsharp it outputs:

Before:
3
After:
nil
End

In my script I want to add and remove a lot of values in a table so I always end up with a huge table filled with nil values, which is useless. table.remove(tbl, pos) don't work because pos must be an integer of the position, and can't be a string for the key like here with the associative array.

VM Debugger crash when watching a global var

xpcall is currently a dumb wrapper over pcall

xpcall is a dumb wrapper over pcall.
A "serious" implementation of xpcall requires the debug lib to be useful, which is not portable to moon#.
We might want to just have xpcall spit tracebacks and pcall work as it does now.

UserData with private properties throws on UserData.RegisterType

https://groups.google.com/forum/#!topic/moonsharp/LWu5NoPju2Y

ANTLR parsing can be exceptionally slow in some cases

Syntax errors have error highlight broken

String library not passing tests.

Tutorials on website to be completed

Integer rounding in libs is done with wrong rounding

Threading check not working properly

• Processor.LeaveProcessor must reset m_OwningThreadID.
• Have an option to disable the test anyway, as there are corner cases which are legal and yet would trigger the exception (e.g. switching thread and back inside a clr callback).

Revise Exception ctor overloads

Revise Exception ctors, because the string can potentially contain tokens interpreted by string.Format.. see for example InterpreterException ctor.

String patterns do not support \0 characters - %z must be used instead.

Patterns are implemented in Lua 5.1 way.

This is to port them to Lua 5.2.

Not urgent for sure - at the moment won't fix.

The frontier pattern %f might throw an IndexOutOfRangeException

The frontier pattern %f might throw an IndexOutOfRangeException
At this moment this is a won't fix.
Consider disabling the pattern.

pcall returns only the first return value

https://groups.google.com/forum/#!topic/moonsharp/LWu5NoPju2Y

Coroutine.resume does not handle errors gracefully.

This crashes:

    public static void Main()
    {
        string code = @"
            function a()
                callback(b)
            end

            function b()
                coroutine.yield();
            end                     

            c = coroutine.create(a);

            coroutine.resume(c);        
            ";

        // Load the code and get the returned function
        Script script = new Script();

        script.Globals["callback"] = DynValue.NewCallback(
            (ctx, args) => args[0].Function.Call()
            );

        DynValue function = script.DoString(code);

        // This raises an error of "attempt to yield from outside a coroutine"
        function.Function.Call();


        Console.ReadKey();
    }

Improve TypeDescriptors

• Support custom descriptors
• Support different policies for unregistered types
• Support overloads in some way
• Support automatic case conversion as an option

MoonSharp fails a simple test script that uses table functions.

The script is TableIntGet.lua, a rather trivial one:

local t = {};
-- C-Lua schneller
for i = 1,10000,1 do
    t[i] = i;
end;

-- interessant! C-Lua ziemlich lahm
for i = 1,100,1 do
    table.remove(t, i + 1000);
end;
for i = 1,100,1 do
    table.insert(t, i + 1000, 1);
end;

-- C-Lua schneller
local sum = 0;
for i = 1,10000,1 do
    sum = sum + t[i];
end;

The exception is:

MoonSharp.Interpreter.ScriptRuntimeException: attempt to perform arithmetic on a nil value
   at MoonSharp.Interpreter.Execution.VM.Processor.ExecAdd(Instruction i, Int32 instructionPtr) in c:\git\moonsharp\src\MoonSharp.Interpreter\Execution\VM\Processor\Processor_InstructionLoop.cs:line 806
   at MoonSharp.Interpreter.Execution.VM.Processor.Processing_Loop(Int32 instructionPtr) in c:\git\moonsharp\src\MoonSharp.Interpreter\Execution\VM\Processor\Processor_InstructionLoop.cs:line 283
   at MoonSharp.Interpreter.Execution.VM.Processor.Call(DynValue function, DynValue[] args) in c:\git\moonsharp\src\MoonSharp.Interpreter\Execution\VM\Processor\Processor.cs:line 61
   at MoonSharp.Interpreter.Script.Call(DynValue function) in c:\git\moonsharp\src\MoonSharp.Interpreter\Script.cs:line 269
   at MoonSharp.Interpreter.Script.DoString(String code, Table globalContext) in c:\git\moonsharp\src\MoonSharp.Interpreter\Script.cs:line 202

The script is executed via a simple DoString(). Both LuaInterface and NeoLua handle it without any errors.

Test load methods default _ENV behaviour

Link on http://www.moonsharp.org/moonluadifferences.html is dead

Link to google docs file is dead:

The standard library may at points be wildly different - Check here for an overview of the standard library status.

Analyze possible splitting of string type in binary and text

Find a way to resolve overloads on userdatas

Function in lua which has 2 parameters with the same name throws error

https://groups.google.com/forum/#!topic/moonsharp/LWu5NoPju2Y

Keep a GUID in Tables, functions etc. instead of Script reference to avoid leaks

Nuget package forces Antlr4.Runtime.net35.dll on all frameworks

Currently Antlr4 runtime is not a dependency in the nuget package, but forced as a reference. This is intentional, otherwise the nuget package wouldn't work with frameworks 4.x.

The side effect, however, is that any project which uses Moon# and Antlr4 for other scripting uses, has a conflict.

Compilation error messages are unhelpful and different from Lua standards

All error messages in compilation phase are not very helpful.
Plus they are different from Lua standards, lack source reference, etc.

In 301 basic test, these were temporarily commented out with " ERRORMSG " comments.

Metamethods can tail? Also index and newindex?

Implement source level debugger

Investigate tail recursion

This issue was created in Task Tub

_ENV not present as local/upvalue in functions not using globals

Change Unicode escape sequence in strings to conform to Lua 5.3 one

\u{xxxx} with { and } mandatory.

Void management is not exactly as Lua does

function x() end
print(x(), 3, x(), 4, x(), x())
Lua : nil 3 nil 4 nil
MoonSharp : nil 3 nil 4

However, for default params it's helpful the way MoonSharp does.

Also, voids must be checked for compatibility with varargs.

Add a conversion to delegates

https://groups.google.com/forum/#!topic/moonsharp/tSqnKSJn7_c

Define tests for dynamic eval

Port Diarmuid userdata registration helper

public static void InitUserData()
{
var userDataTypes =
from t in Assembly.GetExecutingAssembly().GetTypes()
let attributes = t.GetCustomAttributes(typeof(MoonSharpUserDataAttribute), true)
where attributes != null && attributes.Length > 0
select t;

foreach (var userDataType in userDataTypes)
{
UserData.RegisterType(userDataType);
}
}