Combining Lua and Free Pascal.

[Dilan Rona]

Sorry for the late reply. I ended giving up on the project due to the lack of support overall, and because I simply couldnt do with freepascal at the time I could do with Borland Pascal. Main reason being the lack of a crt unit after a fresh install of Free Pascal.

This is the test pascal file that is working as of today, reorganized the register functions to above the main.lua file being loaded.

program lua_test;

uses
        crt,
        lua,
        lualib,
        lauxlib;

var
        L: plua_state;
{--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--}
function new_print(L: Plua_State): LongInt; cdecl;
{
    Redefined print here as it causes problems when using freepascal with Lua.
    Executing code from fpc, and using print in lua results in the cursor not
going back to the beginning.
}
var
        vars:string;
        i:integer;

begin
        vars:='';
        for i:=1 to lua_gettop(L) do begin
                if i = 1 then vars:=vars + lua_tostring(L, i) else vars:=vars + '    ' + lua_tostring(L, i);
        end;

        writeln(vars);
        new_print:=0;
end;
{--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--}
function cls(L: Plua_State): LongInt; cdecl;
begin
        clrscr();
        cls:=0;
end;
{--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--}
procedure SendtoLua(); cdecl;
begin
        writeln('===================');
        lua_getglobal(L, 'luatest');
        lua_pushinteger(L, 5);
        lua_pushstring(L, 'r2wea');
        lua_pushboolean(L, true);
        {   call:   x args, y result }
        lua_call(L, 3     , 4        );
        writeln ('Pascal received: ', lua_tointeger(L, -4),', ', lua_tostring(L, -3),', ', lua_tointeger(L, -2), ', ', lua_toboolean(L, -1));
        writeln('===================');
end;
{--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--=-==-=--}
begin
        clrscr;
        L := luaL_newstate();

        {check if the lua engine is loaded.}
        if (L = nil) then begin
                writeln('Lua engine not loaded! Terminating!');
                exit;
        end else begin
                writeln('Step 1: Loading Lua engine.');
                luaL_openlibs(L);

                {Register freepascal functions and procedures before loading the lua file.}
                lua_register(L, pchar('cls'), @cls);
                lua_register(L, pchar('new_print'), @new_print);
                if lua_dofile(L, pChar('main.lua')) <> 0 then begin
                        Write('Error Detected: ');
                        WriteLn(lua_tostring(L, -1));
                        exit;
                end;
        end;

        {Check if the main.lua file exists, and executes it.}
        writeln('Step 3: Loaded, and Executed the lua script.');
{=======================================================================================================================
Main code for execution goes here.
=======================================================================================================================}
        SendtoLua();

        lua_close(L);
end.

The main.lua file is here.

--oprint = print -- Saving original print
--print = new_print -- Redefinging print
asd={}
asd.d=1
asd.e=3

function luatest(aaa,bbb,ccc)
    print('calling lua test')
    print('Lua received: ' .. aaa .. ', ' .. bbb .. ', ' .. type(ccc) .. '.\n')

    if ccc == true then
        print('this is true')
    else
        print('this is false')
    end

    print('Alpha.')
    print("Beta.")
    return 99,"a77",43, asd
end

--cls()
new_print('Test line.')
print('Step 2: Loaded main.lua. ')
print('Testing.')

Its not the cleanest project, i'll admit. As it was meant as a proof of concept for me. Since freepascal does ship with Lua 5.1 (which i do need above the latest versions), this is what I'll be using myself. I'll do some cleanup, see if i can get the project to do what i need it to do, and see what direction i can take it in terms of a possible console game.