Lua on iPhone?

Question

I am trying to use Lua on the iphone. On Mac OSX, in a normal Cocoa application (not iPhone), I used the following code:

lua_State* l;
l = lua_open();
luaL_openlibs(l);
luaL_loadstring(l, "print(\"hi from LUA\");");
lua_pcall(l, 0, 0, 0);

I downloaded Lua 5.1.4 from lua.org/ftp and I compiled it for Mac OSX. In the Xcode project, I have used "add existing framework" to add liblua.a and I have used "add existing files" to add the include directory.

This works as expected, and prints the string: "hi from LUA". When I try the same thing in a iPhone project, it gives the errors:

"_luaL_newstate", referenced from:
_main in main.o
more of the same thing...
symbol(s) not found
collect2: ld returned 1 exit status

It seems that the .a file is not linked into the iPhone app. Does anybody know how to make this work?

By the way, I do not really care that Apple might not accept my app if it has Lua in it.

Answer 1

You'll need to compile the LUA .a for ARM, not Intel. If the LUA library uses autoconf, you can use my favorite iphone/autoconf builder: build_for_iphoneos. If it's not autoconf, then you can use that script to get an idea of how to attack it. Sometimes you can just build a Static Library Xcode project, dump all the files into it and hit build. If the build is simple enough, it'll do most of the work for you.

I know it doesn't matter for your use, but LUA-based tools are generally shippable on the app store. You just can't download arbitrary code at run time and interpret it.

Answer 2

This isn't an answer... but I followed what you said that you did, nazgul42, and it seemed to work(make a Static Library project, then, a static library target was already there*duh* and it seemed to compile properly). It spat out a .a file which i believe is iPhone/xCodes version of the .lib file? I included it in another blank project, and I'm not sure how to include the lua functions? I tried include "lua.h" and stuff, but it doesn't seem to work... how do you include the main lua.h header file?

btw: I put the .a file in my Other Sources folder/group of my project.

Answer 3

You might want to check out iPhone Wax. It is a lua/iPhone bridge that lets you write native iPhone apps in pure lua! Here is a pretty good tutorial about it.