1. بسم الله الرحمن الرحیم

2. Lua Real embeddable Script Language

3. History
Lua was created in 1993 by Roberto Ierusalimschy, Luiz Henrique de Figueiredo, and Waldemar Celes, members of the Computer Graphics Technology Group (Tecgraf) at the Pontifical Catholic University of Rio de Janeiro, in Brazil.

4. What is Lua dynamic language scripting language Embedded
in C/C++, Java, Fortran, C#,Perl, Ruby, Ada, etc.
portability
simplicity
small size

5. Like basic
Types:
"nil" "boolean" "number""string" "table" "function" "thread" “userdata”
Comment
--one Line comment
--[[ Multi-line comments]]
multiple assignments
a,b=10,
Operators
* / % = #
and or not
== ~= >= <= < >
() []

6. function name ( args ) body [return values] end
do block end
if exp then
block
{elseif exp then block}
[else block]
end
while exp do block end
repeat block until exp
for var = start, end [, step] do block end
for vars in iterator do block end
Break
local a=12
Local a=function (args) body [return values] end

7. boolean
b=true
b=false
number
I=12.3
table
t = {}
t = {"yes", "no", "?"}
t = {x=5, y=10}
t = {x=5, y=10; "yes", "no"}
t[“x”]=”rahim”;
t.x=”firouzi”
string
s=”rahim”
s='firouzi'
S= [=[ multi line string ]=]

8. OOP
Use table for oop
Example obj→func(p1,p2) ====> Obj:func(p1,p2) == obj[“func”](obj,p1,p2)
Use table for module
io.print(p1) == io[“print”](p1)
OOP example
local Vector = {}
Vector.__index = Vector
function Vector:new(x, y, z) The constructor
return setmetatable({x = x, y = y, z = z}, Vector)
end
function Vector:magnitude() Another method
return math.sqrt(self.x^2 + self.y^2 + self.z^2)

9. Useful function
type(var)
print( … )
ipairs (t)
pairs (t) _G
_VERSION

10. lib string string.len (s) string.sub (s, i [, j]) string.upper (s)
string.lower (s)
string.format (s [, args]) IO
io.read (formats)
io.write (values)
Math
math.sqrt (x)
math.sin (a)
math.cos (a)

11. lib file io.open (fn [, m]) file:close () file:read (formats)
file:lines ()
file:write (values)
file:flush () OS
os.execute (cmd)
os.exit ([code])
os.time ([tt])
os.date ([fmt [, t]])

12. How to run lua program Interpretor Lua sudo apt-get install luaX.X lua
Embedded in other programming
Use lib

13. Embedded
An embedded style language is a kind of computer language whose commands appear intermixed with those of a base language.
Lua example:adobe lightroom
Python example:Gimp ,Blander
Scheme example:gdb,gEDA
JavaScript → ECMAScript example: web browsers
TCL example:NS-2

14. Embedded Use stack to communication by lua Make state
Add c function in state
Run lua script for preset
Call lua function by c

15. embedded
Main program
Lua program
Function link
Call function
return

16. C example #include <stdio.h>
#include <lua.h> //Lua main library (lua_*)
#include <lauxlib.h> //Lua auxiliary library (luaL_*)
int main(void) {
//create a Lua state
lua_State *L = luaL_newstate();
//load and execute a string
if (luaL_dostring(L, "function foo (x,y) return x+y end")) {
lua_close(L);
return -1; }
//push value of global "foo" (the function defined above)
//to the stack, followed by integers 5 and 3
lua_getglobal(L, "foo");
lua_pushinteger(L, 5);
lua_pushinteger(L, 3);
lua_call(L, 2, 1); //call a function with two arguments and one return value
printf("Result: %d\n", lua_tointeger(L, -1)); //print integer value of item at stack top
lua_close(L); //close Lua state
return 0;
wikipedia

17. Add function static int hello (lua_State *L) {
double f = luaL_checknumber(L, 1);
lua_pushstring(L, “hello world”);
return 1; } …
lua_pushcfunction(L, hello);
lua_setglobal(L, “hello”);
...

18. Try

19. Tanks