Re: [Q] simple translator from Lua to Java Script and PHP

[KHMan <keinhong@...>]

V S P wrote:
> [snip]
> I installed the [luaanalyze-20080925b.tar.gz]
> got it to run on the example file -- no problems.
> However, there is no documentations/samples on how to use this
> (since this is workin in progress).  And I am having difficulties
> figuring out out the
> basic APIs to walk through the AST, and assign actions (if I need
> any for translation).

Many of the things listed in the LuaGrammar page are likely to be 
experimental stuff. As such, if you prefer an actively supported 
project and something that looks like a complete piece of 
software, then Fabien's metalua is definitely a good choice.

> c) Still having difficulties to get metalua to run on windows
> (but the metalua's gg/mlp works in the luaanalyse above -- so I am
> thinking when Fabian has time for getting the whole metalua support
> for windows/vs 2005/lua 5.1.4 -- I will at least get some knowledge
> of dealing with AST using luaanlyze)

If this is a stand-alone project, why not get MinGW up and 
running, since metalua has the correct Makefiles and config for that.

> d) the other projects listed there were not actively worked on
> (or may be I missed some) 

This is a rather small niche area, so you're not likely to see 
very active development. For example, I fiddle with Yueliang when 
I feel like it, or when prompted by the requirements of other 
projects like LuaSrcDiet. It's up to you to decide what type of 
tool you want to apply to the problem.

> [snip]
> Again, for my needs, I want to translate If/else  and for loop blocks
> of lua code to javascript (very constrained lua code with 3 or 4 
> function calls) and basic <  ~=  ==  >  operators within the 
> 'if  elseif  else' expressions.  Javascript is already typeless
> so I am not worrying about 'internal' type of variables, table elements
> or any duck-typing issues.

From your OP:

if tbA[id4]<tbB[id87]  then
   tbA[id4].myfunction
end

If your snippets are very predictable, you just need to fiddle 
with token patterns, which would be pretty simple to do, but not 
very flexible. But if there are future needs, then parsing may be 
better.

If you want to do quick-and-dirty parsing, and isn't leery about 
not going with orthodox methods like AST, then grab LuaSrcDiet. I 
have done a parser skeleton there and you get all tokens in a nice 
table, even all the non-tokens. Find the appropriate parts of the 
grammar (stat, expr_stat, if_stat, cond, block, expr, subexpr, 
primaryexp, prefixexp, field, yindex, ...) then add code to 
translate certain constructs, replacing the original tokens. Write 
out the modified token stream and voila! you're all done.

--
Cheers,
Kein-Hong Man (esq.)
Kuala Lumpur, Malaysia