Re: dofile, loadfile, loadstring in a coroutine

[Graham Wakefield <lists@...>]

Summary:

lua_resume() on the main Lua state (instead of e.g. pcall) works.

This also works after loading a different script, e.g. a token filter defined in a lua script.

However, after this, calls to loadstring(), dofile() etc. in Lua do not work (but neither do they throw an error).  Somehow it appears as if the token filter is trashing/zeroing the loaded chunks.

Not sure why - is it because the FILTER definition also employs coroutines?

On Apr 21, 2007, at 6:39 PM, lists@grahamwakefield.net wrote:

extern "C" {

#include "lua.h"

#include "lualib.h"

#include "lauxlib.h"

}

int main (int argc, char ** argv)

{

char * filename = "/test1.lua";

int result;

lua_State * L = luaL_newstate(); //lua_newstate(Lua :: alloc, 0);

if (L) {

luaL_openlibs(L);

// luaL_dofile(L, "/preload1.lua"); // *1*

if (luaL_loadfile (L, filename))

{

printf("luaL_loadfile error: %s", lua_tostring(L, -1));

printf("luaL_loadfile failed");

lua_pop(L, 1);

}

else

{

result = lua_resume(L, lua_gettop(L) - 1);

printf("lua_resume result %i\n", result);

}

} else {

printf("luaL_newstate failed\n");

}

return 0;

}

-- debug filter

local function IN(get,put)

put("IN init")

while true do

local line,token,value=get()

print(line,token,value)

put(line,token,value)

end

end

local function OUT(get,put)

put("OUT init")

while true do

local line,token,value=get()

print("",line,token,value)

put(line,token,value)

end

end

local function pipe(f,get,put)

put = put or coroutine.yield

local F=coroutine.wrap(f)

F(get,put)

return F

end

function FILTER(get,source) FILTER=pipe(OUT,pipe(IN,get)) end