Hi. I've been trying to build the new parser (the prebuilt version is now out-of-date), and I'm running into a LOT of "Resolve R/R conflict (use first production declared in grammar.)
(2,21, 2,14) -> 2,14Resolve R/R conflict (use first production declared in grammar.)" sort of warnings.

These seem to be manifesting as errors along the lines of:

error during main.lua : Error: Parse error on line 26:
...s(tiles) do
TILES[#TILES + 1] = love.
----------------------^
Expecting '=', ',', got '[' :

Rearranging some lines will give me similar errors with other operators.

(From https://dl.dropbox.com/u/14510154/TESTS/take_the_fork/main.lua )

I tried to tease out any parser shenanigans but found myself rather swamped. 😄

I don't have much of an environment set up to run the makefile (I have Cygwin on some other machine...), but I ran it both through node and the web generator at http://zaach.github.com/jison/try/ with similar results.

Thanks in advance for any help or hints on this.

3 Issues:

1. Arguments not passed to the top level function of a parsed chunk (via ...).
2. Parsed chunk has it's own global environment.
3. Lua understands calling function with func()() but javascript needs () around i.e. (func())()

From command line,

% lua -e 'var=123 loadstring"print(var,...)"(456)'

gives:

123     456

In chrome,

<script src=lua+parser.min.js></script>
<script>lua_load('var=123 loadstring"print(var,...)"(456)')();</script>
<script>lua_load('var=123 (loadstring"print(var,...)")(456)')();</script>
<script>lua_load('var=123 (loadstring"print(var)")(456)')();</script>

gives:

Uncaught Error: Parse error on line 1:
...print(var,...)"(456)
-----------------------^
Expecting '(', ':', '.', 'STRING', '{', '[', got 'EOF' lua+parser.min.js:127
Uncaught ReferenceError: varargs is not defined
undefined lua+parser.min.js:16

I've noticed that when calling require from Lua.js, it doesn't return anything. The code inserted into each compiled Lua module is:

G.str['require'] = function (name) {
  lua_require(G, name);
};

Lua's reference manual states that require should return a value:

Once a loader is found, require calls the loader with a single argument, modname. If the loader returns any value, require assigns the returned value to package.loaded[modname]. If the loader returns no value and has not assigned any value to package.loaded[modname], then require assigns true to this entry. In any case, require returns the final value of package.loaded[modname].

Lua.js isn't doing the bolded part.

I may submit a patch for this if I can figure it out. This is part of my attempt to get the table method of defining a module to work in Lua.js (see #13).

I encountered this bug while compiling to JS real-life Lua. This minimal code triggers it:

function a() end
while true do
    break
end

This gets compiled to:

G.str['a'] = (function () {
  var tmp;

  return [];
})
while (true) (function() {
  return;
})();

Notice the immediately-invoked function expression (IIFE) inside the while loop in the generated JS code. The Lua break statement is compiled into a return call but all it does is leave the function body, not the loop. So the loop, which should exit immediately, runs forever (and locks up the browser).

The Lua function declaration function a() end at the top is required to trigger the insertion of the IIFE and thus the bug.

This sample don't work, because of
local mt = getmetatable(t)
and
setmetatable(res,mt)
.

--recursive deep copy
function table.copy(t)
if type(t) ~= 'table' then return t end
local mt = getmetatable(t)
local res = {}
for k,v in pairs(t) do
if type(v) == 'table' then
v = table.copy(v)
end
res[k] = v
end
setmetatable(res,mt)
return res
end

Also this sample doesn't work.

function table.copy(object)
local lookup_table = {}
local function _copy(object)
if type(object) ~= "table" then
return object
elseif lookup_table[object] then
return lookup_table[object]
end
local new_table = {}
lookup_table[object] = new_table
for index, value in pairs(object) do
new_table[_copy(index)] = _copy(value)
end
return setmetatable(new_table, getmetatable(object))
end
return _copy(object)
end

Any hints?

Example code:

test = {4,1,2}
print(test[1],test[2],test[3])
test[2] = 3
print(test[1],test[2],test[3])

Prints:

4 1 2
null 3 null

Hi,

I found this repo while reading up about Lua and found it interesting.
I cloned it and tried building but there were two issues I came across:

1. It no longer builds with the modern Node v10+
2. Closure Compiler latest version URL changed and also the JAR filename itself in it

While I know that this is a dormant project and there's a chance that nobody will look at it, I still wanted to update the project with a couple of fixes I made, to be able to run this in late 2018 too.

There are 2 pull requests:

• #42 - Compatibility for Node v10
• #43 - Fix closure compiler build

I merged these two in my fork (https://github.com/nomaed/lua.js/tree/master) in case anyone wants to build it but these PRs won't be merged in here.

When using a goto in my Lua code, the lua2js tool dies with the following error message:

    throw new Error(str);
    ^

Error: Parse error on line 4778:
... == 0 then               goto stop           end       if id
----------------------^
Expecting '(', ':', '.', 'STRING', '{', '[', got 'NAME'
    at Parser.parseError (/home/runner/Monomod/luajs/lua2js:606:11)
    at Parser.parse (/home/runner/Monomod/luajs/lua2js:658:22)
    at Object.<anonymous> (/home/runner/Monomod/luajs/lua2js:1093:21)
    at Module._compile (node:internal/modules/cjs/loader:1101:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:79:12)
    at node:internal/main/run_main_module:17:47

I'll see if I can fix this by changing my Lua code to not use goto. (I didn't write the code; I'm just modifying it.)

Hello there !

I am currently adding the missing string functions and I use a fork of sprintf.js to power string.format().

My question is where put the code of sprintf in lualib.js or anywhere in the repo ?
Adding a minified version directly in lualib.js works well but I am not sure it's the best way to handle this ?
Adding a separate file in src/ and using require() in lualib should works too but I don't have a node.js environment to test this.
Or maybe include sprintf's code during the build of lua_paser ?

Also, the oiginal sprintf.js is under the 3 clauses BSD licence, I don't know how it could go along lua.js's licence ?

Thanks for your insights.

The grammar doesn't allow having a semicolon after a return statement, although it should.

I suspect the fix is fairly straightforward but I'm very much unfamiliar with the grammar definition syntax so I have no idea how to allow an optional ";" token.

https://github.com/ghoulsblade/love-webplayer/blob/master/js/lua-parser-utils.js
include this file to add support for :

string.find
string.gmatch
string.gsub
string.match

my implementation of them is only partial, it covers a lot of common usecases, but it isn't 100% compatible to native lua behavior.

Is there a working JSON encoder/decoder for lua2js? They all seem to use string.find. Or is there another way to communicate from the converted code to the global JS environment?

Hello.

I tried to test if table is empty with "if next(tbl) == nil" but nex() function is unsupported. This is no a big deal, I can use pairs() to test for empty table.

Great library, thanks!

I'd be interested in adding source map support to lua.js.

See the article here: http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/

I want to know how destruct the script lua loaded, to use a buttom stop of my control

Some more! (I'm finally mostly stable, so this might be it for a while.)

bit.band() starts with 0, versus ~0 or whatever is appropriate (for arguments.length > 0 specifically, I believe?).

rawequal() is returning a non-array, too.

Maybe this was accounted for in the "local x = x" patch (I'm still running into build issues...), but if not:

local function foo ()
DoSomethingWith(foo)
end

The inner foo is getting globalized. (Easy enough to work around, so not urgent.)

-- Edit, sneaking one more in here:

In table.remove(), something like

if (pos == null) pos = table.length;

should go at the beginning.

for some reason, the following code doesn't work (parser error) with lua+parser.min.js & lua+parser.js:

    local px = obj1:getPx()
    if (px<self.targetPos[1]) then

replacing

px<self.targetPos[1]

with

self.targetPos[1]>px

works great.

if the second operator is a numeric constant, everything works great also.

Just a thought, if lua2js listened on stdin and returned data on stdout, it could be used as part of a unix pipe; eg:

for i in `1.lua 2.lua 3.lua`; do
  cat $i | lua2js > "$i.js"
done

I'm working on a pull request which should implement this.

As title says, [[\]] in Lua becomes "\" in JS.

Easily fixed with "\\" in Lua, Still...

Hello,

This project is really great!

I'm using it in WebNCL, a web-based implementation of NCL presentation machine. NCL is a multimedia language and one of its features is support fo Lua scripts.

We'd had great success in using the lua.js in your project so far, but I'm facing a problem with requires. I really don't how they work.

Hi all, awesome project, i use it to run games made in luascript for Love2D in a experimental webplayer :
https://github.com/ghoulsblade/love-webplayer

i found a few parser bugs, here's the current list, will track new ones in the readme on my project page.

parser bug : clouds demo : parse error in keypressed : >> love.filesystem.load("main.lua")() << workaround : >> (love.filesystem.load("main.lua"))() <<
parser bug : >> myvar = .5 << workaround >> myvar = 0.5 <<
parser bug : iyfct block comment in main.lua >> --[[ bla... ]]-- << workaround : remove comment (js regexp pre load?) or use single line comments
parser bug : iyfct " in table-save.lua >> ""..string.char(26).."" << workaround : >> '"'.."..string.char(26).."..'"' <<
parser bug : sinescroller >> local mytext = "bla" print(mytext:len()) << workaround >> print(string.len(mytext)) <<

i also added small bits to the lua-parser code that might be helpful to others :
see https://github.com/ghoulsblade/love-webplayer/blob/master/js/lua-parser.js all lines marked with ghoulsblade :

near beginning of parser :
"G = G || lua_newtable2(lua_core);\n" + // added 2012-03-16 by ghoulsblade for love-webplayer
since i use multiple lua files in the same state

"LuaBootStrap(G);\n"+ // added 2012-03-16 by ghoulsblade for love-webplayer
to register some custom functions in the api (love2d engine functionality)

if (arguments.length == 0) return [new Date().getTime()]; // added 2012-03-16 by ghoulsblade for love-webplayer
in os.time

keep up the good work =)

Thanks for accepting my testing pull requests. To enable Travis CI, you'll need to sign in with your Github account at travis-ci.org and enable testing for your repository.

Hi. A couple things that tripped me up.

In the parser, "assert" returns value, where it should return [value]. This was a bit puzzling for a while. 😄

According to the manual, "rawset" (and lua_rawset()) take "any value" for index, which would include nil. (This is sometimes handy.)

Not so much an issue, but I'm using this for "select"... so far so good:

    "select": function(n) {
        if (n === "#")
            return [arguments.length - 1];
        return slice(arguments, n);
    }