common/lualib.h

   1 /*
   2  * lualib.h - useful functions and type for Lua
   3  *
   4  * Copyright © 2009 Julien Danjou <julien@danjou.info>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  */
  21
  22 #ifndef AWESOME_COMMON_LUALIB
  23 #define AWESOME_COMMON_LUALIB
  24
  25 #include <lua.h>
  26
  27 #include "common/util.h"
  28
  29 /** Lua function to call on dofuction() error */
  30 lua_CFunction lualib_dofunction_on_error;
  31
  32 void luaA_checkfunction(lua_State *, int);
  33 void luaA_checktable(lua_State *, int);
  34
  35 /** Dump the Lua stack. Useful for debugging.
  36  * \param L The Lua VM state.
  37  */
  38 void luaA_dumpstack(lua_State *);
  39
  40 /** Convert s stack index to positive.
  41  * \param L The Lua VM state.
  42  * \param ud The index.
  43  * \return A positive index.
  44  */
  45 static inline int
  46 luaA_absindex(lua_State *L, int ud)
  47 {
  48     return (ud > 0 || ud <= LUA_REGISTRYINDEX) ? ud : lua_gettop(L) + ud + 1;
  49 }
  50
  51 static inline int
  52 luaA_dofunction_error(lua_State *L)
  53 {
  54     if(lualib_dofunction_on_error)
  55         return lualib_dofunction_on_error(L);
  56     return 0;
  57 }
  58
  59 /** Execute an Lua function on top of the stack.
  60  * \param L The Lua stack.
  61  * \param nargs The number of arguments for the Lua function.
  62  * \param nret The number of returned value from the Lua function.
  63  * \return True on no error, false otherwise.
  64  */
  65 static inline bool
  66 luaA_dofunction(lua_State *L, int nargs, int nret)
  67 {
  68     /* Move function before arguments */
  69     lua_insert(L, - nargs - 1);
  70     /* Push error handling function */
  71     lua_pushcfunction(L, luaA_dofunction_error);
  72     /* Move error handling function before args and function */
  73     lua_insert(L, - nargs - 2);
  74     int error_func_pos = lua_gettop(L) - nargs - 1;
  75     if(lua_pcall(L, nargs, nret, - nargs - 2))
  76     {
  77         warn("%s", lua_tostring(L, -1));
  78         /* Remove error function and error string */
  79         lua_pop(L, 2);
  80         return false;
  81     }
  82     /* Remove error function */
  83     lua_remove(L, error_func_pos);
  84     return true;
  85 }
  86
  87 #endif
  88
  89 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80