Hi,
In C++, I have a map<string, string>
, containing an unknown number of entries. How can I pass this to a Lua function, so that the Lua function can use the data as a table?
Hugo
Hi,
In C++, I have a map<string, string>
, containing an unknown number of entries. How can I pass this to a Lua function, so that the Lua function can use the data as a table?
Hugo
A couple options...
Copy the map into a new Lua table, and pass the Lua table.
Create a proxy table that directs reads and writes through a metatable's __index
and __newindex
metamethods
The drawback to (1) is all the copying, of course.
The drawback to (2) is that pairs()
won't work on the proxy table
A discussion of fixes to Lua for generalized pairs
is in the wiki and this mailing list thread. Generalized pairs
is expected for Lua 5.2
if you want a real lua table:
lua_newtable(L);
int top = lua_gettop(L);
for (std::map::iterator it = mymap.begin(); it != mymap.end(); ++it) {
const char* key = it->first.c_str();
const char* value = it->second.c_str();
lua_pushstring(L, key);
lua_pushstring(L, value);
lua_settable(L, top);
}
with the right types for your map substituted in..