Compiling a DLL to be used in Lua

["Luciano de Souza" <luchyanus@...>]

Hi listers,

I am trying to write a DLL with code callable for Lua. I can understand this example, but it's not enough to do what I want.

 

program h9k;

{$mode objfpc}{$H+}

uses

Classes, SysUtils, lua;

 

var

L : PLua_State;

 

function lua_readln(L : PLua_State) : integer; cdecl; // Standard Lua method type

var

i, n : Integer;

s : AnsiString;

begin

n := lua_gettop(L); // Find out how many arguements the method was called with

for i := 1 to n do // Loop through all of the arguements

write(lua_tostring(L, i)); // Convert to string and write to stdout (console window)

readln(s); // Call readln, and get back a string of input

lua_pushstring(L, PChar(s)); // push what we read onto the lua stack as a return value

lua_readln := 1; // State that we returned one value

end;

 

begin

L := lua_open; // Create a new lua instance luaL_loadfile(L, PChar(ParamStr(1))) // Then load the file luaL_loadbuffer(L, DefaultCode, Length(DefaultCode), DefaultName); // Else load the default script

luaL_openlibs(L); // Load ALL standard libraries (base, table, io, os, string, math, and package)

luaL_loadfile(L, PChar(ParamStr(1))) // Then load the file

lua_register(L, 'readln', @lua_readln); // Register a custom method

lua_pcall(L, 0, 0, 0); // Execute the script

lua_close(L); // Close the lua instance

end.

 

Suppose I desire to store lua_readln in a DLL and later to use in a Lua script as it occurs with, for example, with Iuplua.dll.

 

library h9k;

{$mode objfpc}{$H+}

uses

Classes, SysUtils, lua;

var

L : PLua_State;

 

function lua_readln(L : PLua_State) : integer; cdecl; // Standard Lua method type

var

i, n : Integer;

s : AnsiString;

begin

n := lua_gettop(L); // Find out how many arguements the method was called with

for i := 1 to n do // Loop through all of the arguements

write(lua_tostring(L, i)); // Convert to string and write to stdout (console window)

readln(s); // Call readln, and get back a string of input

lua_pushstring(L, PChar(s)); // push what we read onto the lua stack as a return value

lua_readln := 1; // State that we returned one value

end;

 

begin

{code}

end.

 

The problem is what to place as a initialization code. I don't need to use loadfile neither pcall because I don't want to call a Lua script. But I think I need to use lua_register because I need to say to Lua wich name will be exported.

Whats wrong? the result DLL can't be loaded with "require".

 

Luciano de Souza