Call Lua from String

#include <stdio.h>
#include <stdlib.h>
#include "lua5.2/lua.h"
#include "lua5.2/lualib.h"
#include "lua5.2/lauxlib.h"

// Our main function
void my_main(lua_State*);

// Vector class
void vector(lua_State*);

// Error handling
void bail(lua_State*, const char*);

int main() {
  // Init Lua
  lua_State* Lua = luaL_newstate();

  // Call Lua base library
  luaopen_base(Lua);

  // Call Lua auxiliary library
  luaL_openlibs(Lua);

  // Load Vector class
  vector(Lua);

  // Load our main function
  my_main(Lua);

  // Clean up Lua state
  lua_close(Lua);

  return 0;
}

// Our main function
void my_main(lua_State* L) {
  int state =
    luaL_dostring(L,
                  "v = Vector:from_table({1, 2, 3, 4});"
                  "assert(#v == 4);"
                  "assert(v[1] == 1);");
  if (state != LUA_OK) {
    bail(L, "Failed to load main block\n");
  }
}

// Vector class
void vector(lua_State* L) {
  int state =
    luaL_dostring(L,
                  "Vector = {};"
                  "Vector.__index = Vector;"
                  "function Vector:new(size);"
                  "    local self = {};"
                  "    for i = 1, size do;"
                  "        table.insert(self, 0);"
                  "    end;"
                  "    setmetatable(self, Vector);"
                  "    return self;"
                  "end;"
                  "function Vector:from_table(t);"
                  "    local v = Vector:new(#t);"
                  "    for i = 1, #t do;"
                  "        v[i] = t[i];"
                  "    end;"
                  "    return v;"
                  "end;");
    if (state != LUA_OK) {
      bail(L, "Failed to load Vector class\n");
    }
}

void bail(lua_State* L, const char* msg) {
  fprintf(stderr, "ERROR: %s: %s\n",
          msg, lua_tostring(L, -1));
  lua_close(L);
  exit(EXIT_FAILURE);
}