init

1 files changed, 1079 insertions, 0 deletions

diff --git a/luaT/luaT.c b/luaT/luaT.c
new file mode 100644
index 0000000..7b85ce3
--- /dev/null
+++ b/luaT/luaT.c
@@ -0,0 +1,1079 @@
+#include <stdlib.h>
+#include <string.h>
+
+#include "luaT.h"
+
+void* luaT_alloc(lua_State *L, long size)
+{
+  void *ptr;
+
+  if(size == 0)
+    return NULL;
+
+  if(size < 0)
+    luaL_error(L, "$ Torch: invalid memory size -- maybe an overflow?");
+
+  ptr = malloc(size);
+  if(!ptr)
+    luaL_error(L, "$ Torch: not enough memory: you tried to allocate %dGB. Buy new RAM!", size/1073741824);
+
+  return ptr;
+}
+
+void* luaT_realloc(lua_State *L, void *ptr, long size)
+{
+  if(!ptr)
+    return(luaT_alloc(L, size));
+
+  if(size == 0)
+  {
+    luaT_free(L, ptr);
+    return NULL;
+  }
+
+  if(size < 0)
+    luaL_error(L, "$ Torch: invalid memory size -- maybe an overflow?");
+
+  ptr = realloc(ptr, size);
+  if(!ptr)
+    luaL_error(L, "$ Torch: not enough memory: you tried to reallocate %dGB. Buy new RAM!", size/1073741824);
+  return ptr;
+}
+
+void luaT_free(lua_State *L, void *ptr)
+{
+  free(ptr);
+}
+
+void luaT_stackdump(lua_State *L)
+{
+  int i;
+  const char *tname = NULL;
+  int top = lua_gettop(L);
+  for(i = 1; i <= top; i++)
+  {
+    int t = lua_type(L, i);
+    printf("%3d. ", i);
+    switch(t)
+    {
+      case LUA_TSTRING:
+        printf("'%s'", lua_tostring(L,i));
+        break;
+      case LUA_TBOOLEAN:
+        printf(lua_toboolean(L, i) ? "true" : "false");
+        break;
+      case LUA_TNUMBER:
+        printf("%g", lua_tonumber(L,i));
+        break;
+      case LUA_TUSERDATA:
+        tname = luaT_typename(L, i);
+        printf("userdata %lx [%s]", (long)lua_topointer(L, i), (tname ? tname : "not a Torch object"));
+        break;
+      case 10:
+        tname = luaT_typename(L, i);
+        printf("cdata %lx [%s]", (long)lua_topointer(L, i), (tname ? tname : "not a Torch object"));
+        break;
+      case LUA_TTABLE:
+        lua_pushvalue(L, i);
+        lua_rawget(L, LUA_REGISTRYINDEX);
+        if(lua_isstring(L, -1))
+          tname = lua_tostring(L, -1); /*luaT_typenameid(L, lua_tostring(L, -1)); */
+        else
+          tname = NULL;
+        lua_pop(L, 1);
+        if(tname)
+          printf("metatable [%s]", tname);
+        else
+        {
+          tname = luaT_typename(L, i);
+          printf("table %lx [%s]", (long)lua_topointer(L, i), (tname ? tname : "not a Torch object"));
+        }
+        break;
+      default:
+        printf("Lua object type: %s", lua_typename(L,t));
+        break;
+    }
+    printf("\n");
+  }
+  printf("---------------------------------------------\n");
+}
+
+/* metatable operator methods */
+static int luaT_mt__index(lua_State *L);
+static int luaT_mt__newindex(lua_State *L);
+static int luaT_mt__tostring(lua_State *L);
+static int luaT_mt__add(lua_State *L);
+static int luaT_mt__sub(lua_State *L);
+static int luaT_mt__mul(lua_State *L);
+static int luaT_mt__div(lua_State *L);
+static int luaT_mt__mod(lua_State *L);
+static int luaT_mt__pow(lua_State *L);
+static int luaT_mt__unm(lua_State *L);
+static int luaT_mt__concat(lua_State *L);
+static int luaT_mt__len(lua_State *L);
+static int luaT_mt__eq(lua_State *L);
+static int luaT_mt__lt(lua_State *L);
+static int luaT_mt__le(lua_State *L);
+static int luaT_mt__call(lua_State *L);
+
+/* Constructor-metatable methods */
+static int luaT_cmt__call(lua_State *L);
+static int luaT_cmt__newindex(lua_State *L);
+
+const char* luaT_newmetatable(lua_State *L, const char *tname, const char *parenttname,
+                              lua_CFunction constructor, lua_CFunction destructor, lua_CFunction factory)
+{
+  lua_pushcfunction(L, luaT_lua_newmetatable);
+  lua_pushstring(L, tname);
+  (parenttname ? lua_pushstring(L, parenttname) : lua_pushnil(L));
+  (constructor ? lua_pushcfunction(L, constructor) : lua_pushnil(L));
+  (destructor ? lua_pushcfunction(L, destructor) : lua_pushnil(L));
+  (factory ? lua_pushcfunction(L, factory) : lua_pushnil(L));
+  lua_call(L, 5, 1);
+  return luaT_typenameid(L, tname);
+}
+
+int luaT_pushmetatable(lua_State *L, const char *tname)
+{
+  lua_getfield(L, LUA_REGISTRYINDEX, tname);
+  if(lua_isnil(L, -1))
+  {
+    lua_pop(L, 1);
+    return 0;
+  }
+  return 1;
+}
+
+const char *luaT_typenameid(lua_State *L, const char *tname)
+{
+  if(luaT_pushmetatable(L, tname))
+  {
+    const char *tnameid = NULL;
+    lua_rawget(L, LUA_REGISTRYINDEX);
+    if(lua_isstring(L, -1))
+      tnameid = lua_tostring(L, -1);
+    lua_pop(L, 1); /* the string/nil */
+    return tnameid;
+  }
+  return NULL;
+}
+
+static const char cdataname[] = ""
+  "local _, ffi = pcall(require, 'ffi')\n"
+  "if ffi then\n"
+  "  local id2name = {}\n"
+  "  return function(cdata, name)\n"
+  "    local id = tonumber(ffi.typeof(cdata))\n"
+  "    if id then\n"
+  "      if name then\n"
+  "        id2name[id] = name\n"
+  "        return name\n"
+  "      else\n"
+  "        return rawget(id2name, id)\n"
+  "      end\n"
+  "    end\n"
+  "    return nil\n"
+  "  end\n"
+  "else\n"
+  "  return function() end\n"
+  "end\n";
+
+static const char* luaT_cdataname(lua_State *L, int ud, const char *tname)
+{
+  lua_pushstring(L, "__cdataname");
+  lua_rawget(L, LUA_REGISTRYINDEX);
+  if(lua_isnil(L,-1))
+  {
+    lua_pop(L, 1);
+
+    if(luaL_dostring(L, cdataname)) /* did something go wrong? */
+      luaL_error(L, "internal error (could not load cdataname): %s", lua_tostring(L, -1));
+
+    lua_pushstring(L, "__cdataname");
+    lua_pushvalue(L, -2);
+    lua_rawset(L, LUA_REGISTRYINDEX);
+  }
+  if(!lua_isfunction(L, -1)) /* should not happen */
+    luaL_error(L, "internal error (cdataname is not a function)");
+
+  lua_pushvalue(L, ud);
+  if(tname)
+    lua_pushstring(L, tname);
+  if(lua_pcall(L, (tname ? 2 : 1), 1, 0))
+    luaL_error(L, "internal error (cdataname): %s", lua_tostring(L, -1));
+
+  tname = lua_tostring(L, -1);
+  lua_pop(L, 1);
+
+  return tname;
+}
+
+const char* luaT_typename(lua_State *L, int ud)
+{
+  if(lua_type(L, ud) == 10)
+    return luaT_cdataname(L, ud, NULL);
+  else if(lua_getmetatable(L, ud))
+  {
+    const char *tname = NULL;
+    lua_rawget(L, LUA_REGISTRYINDEX);
+    if(lua_isstring(L, -1))
+      tname = lua_tostring(L, -1);
+    lua_pop(L, 1); /* the string/nil */
+    return tname;
+  }
+  return NULL;
+}
+
+void luaT_pushudata(lua_State *L, void *udata, const char *tname)
+{
+  if(udata)
+  {
+    void **udata_p = lua_newuserdata(L, sizeof(void*));
+    *udata_p = udata;
+    if(!luaT_pushmetatable(L, tname))
+      luaL_error(L, "Torch internal problem: cannot find metatable for type <%s>", tname);
+    lua_setmetatable(L, -2);
+  }
+  else
+    lua_pushnil(L);
+}
+
+void *luaT_toudata(lua_State *L, int ud, const char *tname)
+{
+  void **p = lua_touserdata(L, ud);
+  if(p != NULL) /* value is a userdata? */
+  {
+    if(!luaT_pushmetatable(L, tname))
+      luaL_error(L, "Torch internal problem: cannot find metatable for type <%s>", tname);
+
+    /* initialize the table we want to get the metatable on */
+    /* note that we have to be careful with indices, as we just inserted stuff */
+    lua_pushvalue(L, (ud < 0 ? ud - 1 : ud));
+    while(lua_getmetatable(L, -1)) /* get the next metatable */
+    {
+      lua_remove(L, -2); /* remove the previous metatable [or object, if first time] */
+      if(lua_rawequal(L, -1, -2))
+      {
+        lua_pop(L, 2);  /* remove the two metatables */
+        return *p;
+      }
+    }
+    lua_pop(L, 2); /* remove the two metatables */
+  }
+  return NULL;
+}
+
+int luaT_isudata(lua_State *L, int ud, const char *tname)
+{
+  if(luaT_toudata(L, ud, tname))
+    return 1;
+  else
+    return 0;
+}
+
+void *luaT_checkudata(lua_State *L, int ud, const char *tname)
+{
+  void *p = luaT_toudata(L, ud, tname);
+  if(!p)
+    luaT_typerror(L, ud, tname);
+  return p;
+}
+
+void *luaT_getfieldcheckudata(lua_State *L, int ud, const char *field, const char *tname)
+{
+  void *p;
+  lua_getfield(L, ud, field);
+  if(lua_isnil(L, -1))
+    luaL_error(L, "bad argument #%d (field %s does not exist)", ud, field);
+  p = luaT_toudata(L, -1, tname);
+  if(!p)
+    luaL_error(L, "bad argument #%d (field %s is not a %s)", ud, field, tname);
+  return p;
+}
+
+void *luaT_getfieldchecklightudata(lua_State *L, int ud, const char *field)
+{
+  void *p;
+  lua_getfield(L, ud, field);
+  if(lua_isnil(L, -1))
+    luaL_error(L, "bad argument #%d (field %s does not exist)", ud, field);
+
+  if(!lua_islightuserdata(L, -1))
+    luaL_error(L, "bad argument #%d (field %s is not a light userdata)", ud, field);
+
+  p = lua_touserdata(L, -1);
+
+  return p;
+}
+
+double luaT_getfieldchecknumber(lua_State *L, int ud, const char *field)
+{
+  lua_getfield(L, ud, field);
+  if(lua_isnil(L, -1))
+    luaL_error(L, "bad argument #%d (field %s does not exist)", ud, field);
+  if(!lua_isnumber(L, -1))
+    luaL_error(L, "bad argument #%d (field %s is not a number)", ud, field);
+  return lua_tonumber(L, -1);
+}
+
+int luaT_getfieldcheckint(lua_State *L, int ud, const char *field)
+{
+  lua_getfield(L, ud, field);
+  if(lua_isnil(L, -1))
+    luaL_error(L, "bad argument #%d (field %s does not exist)", ud, field);
+  if(!lua_isnumber(L, -1))
+    luaL_error(L, "bad argument #%d (field %s is not a number)", ud, field);
+  return (int)lua_tonumber(L, -1);
+}
+
+const char* luaT_getfieldcheckstring(lua_State *L, int ud, const char *field)
+{
+  lua_getfield(L, ud, field);
+  if(lua_isnil(L, -1))
+    luaL_error(L, "bad argument #%d (field %s does not exist)", ud, field);
+  if(!lua_isstring(L, -1))
+    luaL_error(L, "bad argument #%d (field %s is not a string)", ud, field);
+  return lua_tostring(L, -1);
+}
+
+int luaT_getfieldcheckboolean(lua_State *L, int ud, const char *field)
+{
+  lua_getfield(L, ud, field);
+  if(lua_isnil(L, -1))
+    luaL_error(L, "bad argument #%d (field %s does not exist)", ud, field);
+  if(!lua_isboolean(L, -1))
+    luaL_error(L, "bad argument #%d (field %s is not a boolean)", ud, field);
+  return lua_toboolean(L, -1);
+}
+
+void luaT_getfieldchecktable(lua_State *L, int ud, const char *field)
+{
+  lua_getfield(L, ud, field);
+  if(lua_isnil(L, -1))
+    luaL_error(L, "bad argument #%d (field %s does not exist)", ud, field);
+  if(!lua_istable(L, -1))
+    luaL_error(L, "bad argument #%d (field %s is not a table)", ud, field);
+}
+
+/**** type checks as in luaL ****/
+int luaT_typerror(lua_State *L, int ud, const char *tname)
+{
+  const char *msg;
+  const char *tnameud = luaT_typename(L, ud);
+
+  if(!tnameud)
+    tnameud = lua_typename(L, ud);
+
+  msg = lua_pushfstring(L, "%s expected, got %s",
+                        tname,
+                        (tnameud ? tnameud : "unknown object"));
+
+  return luaL_argerror(L, ud, msg);
+}
+
+int luaT_checkboolean(lua_State *L, int ud)
+{
+  if(!lua_isboolean(L, ud))
+    luaT_typerror(L, ud, lua_typename(L, LUA_TBOOLEAN));
+  return lua_toboolean(L, ud);
+}
+
+int luaT_optboolean(lua_State *L, int ud, int def)
+{
+  if(lua_isnoneornil(L,ud))
+    return def;
+
+  return luaT_checkboolean(L, ud);
+}
+
+void luaT_registeratname(lua_State *L, const struct luaL_Reg *methods, const char *name)
+{
+  int idx = lua_gettop(L);
+
+  luaL_checktype(L, idx, LUA_TTABLE);
+  lua_pushstring(L, name);
+  lua_rawget(L, idx);
+
+  if(lua_isnil(L, -1))
+  {
+    lua_pop(L, 1);
+    lua_pushstring(L, name);
+    lua_newtable(L);
+    lua_rawset(L, idx);
+
+    lua_pushstring(L, name);
+    lua_rawget(L, idx);
+  }
+
+  luaL_register(L, NULL, methods);
+  lua_pop(L, 1);
+}
+
+
+/* utility functions */
+const char *luaT_classrootname(const char *tname)
+{
+  int i;
+  int sz = strlen(tname);
+
+  for(i = 0; i < sz; i++)
+  {
+    if(tname[i] == '.')
+      return tname+i+1;
+  }
+  return tname;
+}
+
+/* module_name must be a buffer at least as big as tname 
+ * return true if the class is part of a module */
+int luaT_classmodulename(const char *tname, char *module_name)
+{
+  char chars[] = {'.', '\0'};
+  size_t n;
+  n = strcspn(tname, chars);
+  strncpy(module_name, tname, n);
+  module_name[n] = '\0';
+  return tname[n] == '.';
+}
+
+/* Lua only functions */
+int luaT_lua_newmetatable(lua_State *L)
+{
+  const char* tname = luaL_checkstring(L, 1);
+  char module_name[256];
+  int is_in_module = 0;
+  is_in_module = luaT_classmodulename(tname, module_name);
+
+  lua_settop(L, 5);
+  luaL_argcheck(L, lua_isnoneornil(L, 2) || lua_isstring(L, 2), 2, "parent class name or nil expected");
+  luaL_argcheck(L, lua_isnoneornil(L, 3) || lua_isfunction(L, 3), 3, "constructor function or nil expected");
+  luaL_argcheck(L, lua_isnoneornil(L, 4) || lua_isfunction(L, 4), 4, "destructor function or nil expected");
+  luaL_argcheck(L, lua_isnoneornil(L, 5) || lua_isfunction(L, 5), 5, "factory function or nil expected");
+
+  if(is_in_module)
+    lua_getfield(L, LUA_GLOBALSINDEX, module_name);
+  else
+    lua_pushvalue(L, LUA_GLOBALSINDEX);
+  if(!lua_istable(L, 6))
+    luaL_error(L, "while creating metatable %s: bad argument #1 (%s is an invalid module name)", tname, module_name);
+
+  /* we first create the new metaclass if we have to */
+  if(!luaT_pushmetatable(L, tname))
+  {
+    /* create the metatable */
+    lua_newtable(L);
+
+    /* registry[name] = metatable */
+    lua_pushvalue(L, -1);
+    lua_setfield(L, LUA_REGISTRYINDEX, tname);
+
+    /* registry[metatable] = tname */
+    lua_pushvalue(L, -1);
+    lua_pushstring(L, tname);
+    lua_rawset(L, LUA_REGISTRYINDEX);
+
+    /* __index handling */
+    lua_pushcfunction(L, luaT_mt__index);
+    lua_setfield(L, -2, "__index");
+
+    /* __newindex handling */
+    lua_pushcfunction(L, luaT_mt__newindex);
+    lua_setfield(L, -2, "__newindex");
+
+    /* __typename contains the typename */
+    lua_pushstring(L, tname);
+    lua_setfield(L, -2, "__typename");
+
+    /* __metatable is self */
+    lua_pushvalue(L, -1);
+    lua_setfield(L, -2, "__metatable");
+
+    /* by default, __version equals 1 */
+    lua_pushnumber(L, 1);
+    lua_setfield(L, -2, "__version");
+
+    /* assign default operator functions */
+    lua_pushcfunction(L, luaT_mt__tostring);
+    lua_setfield(L, -2, "__tostring");
+
+    lua_pushcfunction(L, luaT_mt__add);
+    lua_setfield(L, -2, "__add");
+
+    lua_pushcfunction(L, luaT_mt__sub);
+    lua_setfield(L, -2, "__sub");
+
+    lua_pushcfunction(L, luaT_mt__mul);
+    lua_setfield(L, -2, "__mul");
+
+    lua_pushcfunction(L, luaT_mt__div);
+    lua_setfield(L, -2, "__div");
+
+    lua_pushcfunction(L, luaT_mt__mod);
+    lua_setfield(L, -2, "__mod");
+
+    lua_pushcfunction(L, luaT_mt__pow);
+    lua_setfield(L, -2, "__pow");
+
+    lua_pushcfunction(L, luaT_mt__unm);
+    lua_setfield(L, -2, "__unm");
+
+    lua_pushcfunction(L, luaT_mt__concat);
+    lua_setfield(L, -2, "__concat");
+
+    lua_pushcfunction(L, luaT_mt__len);
+    lua_setfield(L, -2, "__len");
+
+    lua_pushcfunction(L, luaT_mt__eq);
+    lua_setfield(L, -2, "__eq");
+
+    lua_pushcfunction(L, luaT_mt__lt);
+    lua_setfield(L, -2, "__lt");
+
+    lua_pushcfunction(L, luaT_mt__le);
+    lua_setfield(L, -2, "__le");
+
+    lua_pushcfunction(L, luaT_mt__call);
+    lua_setfield(L, -2, "__call");
+  }
+
+  /* we assign the parent class if necessary */
+  if(!lua_isnoneornil(L, 2))
+  {
+    if(lua_getmetatable(L, -1))
+      luaL_error(L, "class %s has been already assigned a parent class\n", tname);
+    else
+    {
+      const char* parenttname = luaL_checkstring(L, 2);
+      if(!luaT_pushmetatable(L, parenttname))
+        luaL_error(L, "bad argument #2 (invalid parent class name %s)", parenttname);
+      lua_setmetatable(L, -2);
+    }
+  }
+
+  /* register the destructor function  */
+  if(!lua_isnoneornil(L, 4))
+  {
+    /* does it exists already? */
+    lua_pushstring(L, "__gc");
+    lua_rawget(L, -2);
+
+    if(lua_isnil(L, -1))
+    {
+      lua_pop(L, 1); /* pop nil */
+      lua_pushstring(L, "__gc");
+      lua_pushvalue(L, 4);
+      lua_rawset(L, -3);
+    }
+    else
+      luaL_error(L, "%s has been already assigned a destructor", tname);
+  }
+
+  /* register the factory function  */
+  if(!lua_isnoneornil(L, 5))
+  {
+    /* does it exists already? */
+    lua_pushstring(L, "__factory");
+    lua_rawget(L, -2);
+
+    if(lua_isnil(L, -1))
+    {
+      lua_pop(L, 1); /* pop nil */
+      lua_pushstring(L, "__factory");
+      lua_pushvalue(L, 5);
+      lua_rawset(L, -3);
+    }
+    else
+      luaL_error(L, "%s has been already assigned a factory", tname);
+  }
+
+  /******** Constructor table and metatable ********/
+  lua_pushstring(L, "__constructor");
+  lua_rawget(L, -2);
+  if(lua_isnil(L, -1))
+  {
+    lua_pop(L, 1);                        /* pop nil */
+    lua_newtable(L);                      /* fancy table */
+    lua_newtable(L);                      /* fancy metatable */
+
+    lua_pushvalue(L, -3);                 /* metatable */
+    lua_setfield(L, -2, "__index");       /* so we can get the methods */
+
+    lua_pushcfunction(L, luaT_cmt__newindex);
+    lua_setfield(L, -2, "__newindex");    /* so we add new methods */
+
+    lua_pushcfunction(L, luaT_cmt__call);
+    lua_setfield(L, -2, "__call");        /* so we can create, we are here for only that */
+
+    lua_pushvalue(L, -3);
+    lua_setfield(L, -2, "__metatable");   /* redirect to metatable with methods */
+
+    lua_setmetatable(L, -2);              /* constructor metatable is ... this fancy metatable */
+
+    /* set metatable[__constructor] = constructor-metatable */
+    lua_pushstring(L, "__constructor");
+    lua_pushvalue(L, -2);
+    lua_rawset(L, -4);
+  }
+
+  /* register the constructor function  */
+  if(!lua_isnoneornil(L, 3))
+  {
+    /* get constructor metatable */
+    lua_getmetatable(L, -1);
+
+    /* does it exists already? */
+    lua_pushstring(L, "__new");
+    lua_rawget(L, -2);
+
+    if(lua_isnil(L, -1))
+    {
+      lua_pop(L, 1); /* pop nil */
+      lua_pushstring(L, "__new");
+      lua_pushvalue(L, 3);
+      lua_rawset(L, -3);
+
+      /* set "new" in the metatable too */
+      lua_pushstring(L, "new");
+      lua_pushvalue(L, 3);
+      lua_rawset(L, -5);
+    }
+    else
+      luaL_error(L, "%s has been already assigned a constructor", tname);
+
+    /* pop constructor metatable */
+    lua_pop(L, 1);
+  }
+
+  /* module.name = constructor metatable */
+  lua_setfield(L, 6, luaT_classrootname(tname));
+
+  return 1; /* returns the metatable */
+}
+
+/* Lua only utility functions */
+
+/* add any custom type, provided the object has a metatable */
+int luaT_lua_metatype(lua_State *L)
+{
+  if( (lua_gettop(L) != 2) && (lua_gettop(L) != 3) )
+    luaL_error(L, "expecting: string table [ctype]");
+
+  luaL_checkstring(L, 1);
+  luaL_checktype(L, 2, LUA_TTABLE);
+
+  if(lua_gettop(L) == 3)
+  {
+    if(!luaT_cdataname(L, 3, lua_tostring(L, 1)))
+      luaL_error(L, "could not register cdata type -- missing ffi library?");
+  }
+
+  /* registry[name] = metatable */
+  lua_pushvalue(L, 1);
+  lua_pushvalue(L, 2);
+  lua_rawset(L, LUA_REGISTRYINDEX);
+
+  /* registry[metatable] = tname */
+  lua_pushvalue(L, 2);
+  lua_pushvalue(L, 1);
+  lua_rawset(L, LUA_REGISTRYINDEX);
+
+  return 0;
+}
+
+/* return a userdata from a C pointer */
+/* you are better to know what you are doing */
+int luaT_lua_pushudata(lua_State *L)
+{
+  void *udata = NULL;
+  const char *tname = luaL_checkstring(L, 2);
+
+  if(lua_type(L, 1) == 10)
+    udata = *((void**)lua_topointer(L, 1));
+  else if(lua_isnumber(L, 1))
+    udata = (void*)(long)lua_tonumber(L, 1);
+  else
+    luaL_argerror(L, 1, "expecting number or cdata");
+
+  luaT_pushudata(L, udata, tname);
+
+  return 1;
+}
+
+int luaT_lua_factory(lua_State *L)
+{
+  const char* tname = luaL_checkstring(L, 1);
+  if(luaT_pushmetatable(L, tname) && !lua_isnil(L, -1))
+  {
+    lua_pushstring(L, "__factory");
+    lua_rawget(L, -2);
+  }
+  else
+  {
+    lua_pushnil(L);
+  }
+  return 1;
+}
+
+int luaT_lua_getconstructortable(lua_State *L)
+{
+  const char* tname = luaL_checkstring(L, 1);
+  if(luaT_pushmetatable(L, tname))
+  {
+    lua_pushstring(L, "__constructor");
+    lua_rawget(L, -2);
+    return 1;
+  }
+  return 0;
+}
+
+
+int luaT_lua_typename(lua_State *L)
+{
+  const char* tname = NULL;
+  luaL_checkany(L, 1);
+  if((tname = luaT_typename(L, 1)))
+  {
+    lua_pushstring(L, tname);
+    return 1;
+  }
+  return 0;
+}
+
+int luaT_lua_isequal(lua_State *L)
+{
+  if(lua_isuserdata(L, 1) && lua_isuserdata(L, 2))
+  {
+    void **u1, **u2;
+    luaL_argcheck(L, luaT_typename(L, 1), 1, "Torch object expected");
+    luaL_argcheck(L, luaT_typename(L, 2), 2, "Torch object expected");
+
+    u1 = lua_touserdata(L, 1);
+    u2 = lua_touserdata(L, 2);
+    if(*u1 == *u2)
+      lua_pushboolean(L, 1);
+    else
+      lua_pushboolean(L, 0);
+  }
+  else if(lua_istable(L, 1) && lua_istable(L, 2))
+    lua_pushboolean(L, lua_rawequal(L, 1, 2));
+  else
+    lua_pushboolean(L, 0);
+  return 1;
+}
+
+int luaT_lua_pointer(lua_State *L)
+{
+  if(lua_isuserdata(L, 1))
+  {
+    void **ptr;
+    luaL_argcheck(L, luaT_typename(L, 1), 1, "Torch object expected");
+    ptr = lua_touserdata(L, 1);
+    lua_pushnumber(L, (long)(*ptr));
+    return 1;
+  }
+  else if(lua_istable(L, 1) || lua_isthread(L, 1) || lua_isfunction(L, 1))
+  {
+    const void* ptr = lua_topointer(L, 1);
+    lua_pushnumber(L, (long)(ptr));
+    return 1;
+  }
+  else if(lua_type(L, 1) == 10) /* cdata */
+  {
+    /* we want the pointer holded by cdata */
+    /* not the pointer on the cdata object */
+    const void* ptr = *((void**)lua_topointer(L, 1));
+    lua_pushnumber(L, (long)(ptr));
+    return 1;
+  }
+  else if(lua_isstring(L, 1))
+  {
+    const char* ptr = lua_tostring(L, 1);
+    lua_pushnumber(L, (long)(ptr));
+    return 1;
+  }
+  else
+    luaL_error(L, "Torch object, table, thread, cdata or function expected");
+
+  return 0;
+}
+
+int luaT_lua_setenv(lua_State *L)
+{
+  if(!lua_isfunction(L, 1) && !lua_isuserdata(L, 1))
+    luaL_typerror(L, 1, "function or userdata");
+  luaL_checktype(L, 2, LUA_TTABLE);
+  lua_setfenv(L, 1);
+  return 0;
+}
+
+int luaT_lua_getenv(lua_State *L)
+{
+  if(!lua_isfunction(L, 1) && !lua_isuserdata(L, 1))
+    luaL_typerror(L, 1, "function or userdata");
+  lua_getfenv(L, 1);
+  return 1;
+}
+
+int luaT_lua_getmetatable(lua_State *L)
+{
+  const char *tname = luaL_checkstring(L, 1);
+  if(luaT_pushmetatable(L, tname))
+    return 1;
+  return 0;
+}
+
+int luaT_lua_version(lua_State *L)
+{
+  luaL_checkany(L, 1);
+
+  if(lua_type(L, 1) == 10)
+  {
+    const char *tname = luaT_cdataname(L, 1, NULL);
+    if(tname)
+    {
+      luaT_pushmetatable(L, tname);
+      lua_pushstring(L, "__version");
+      lua_rawget(L, -2);
+      return 1;
+    }
+    return 0;
+  }
+  else if(lua_getmetatable(L, 1))
+  {
+    lua_pushstring(L, "__version");
+    lua_rawget(L, -2);
+    return 1;
+  }
+  return 0;
+}
+
+int luaT_lua_setmetatable(lua_State *L)
+{
+  const char *tname = luaL_checkstring(L, 2);
+  luaL_checktype(L, 1, LUA_TTABLE);
+
+  if(!luaT_pushmetatable(L, tname))
+    luaL_error(L, "unknown typename %s\n", tname);
+  lua_setmetatable(L, 1);
+
+  return 1;
+}
+
+/* metatable operator methods */
+static int luaT_mt__index(lua_State *L)
+{
+  if(!lua_getmetatable(L, 1))
+    luaL_error(L, "critical internal indexing error: no metatable found");
+
+  if(!lua_istable(L, -1))
+    luaL_error(L, "critical internal indexing error: not a metatable");
+
+  /* test for __index__ method first */
+  lua_getfield(L, -1, "__index__");
+  if(!lua_isnil(L, -1))
+  {
+    int result;
+
+    if(!lua_isfunction(L, -1))
+      luaL_error(L, "critical internal indexing error: __index__ is not a function");
+
+    lua_pushvalue(L, 1);
+    lua_pushvalue(L, 2);
+
+    lua_call(L, 2, LUA_MULTRET); /* DEBUG: risque: faut vraiment retourner 1 ou 2 valeurs... */
+
+    result = lua_toboolean(L, -1);
+    lua_pop(L, 1);
+
+    if(result)
+      return 1;
+
+    /* on the stack: 1. the object 2. the value 3. the metatable */
+    /* apparently, __index wants only one element returned */
+    /* return lua_gettop(L)-3; */
+
+  }
+  else
+    lua_pop(L, 1); /* remove nil __index__ on the stack */
+
+  lua_pushvalue(L, 2);
+  lua_gettable(L, -2);
+
+  return 1;
+}
+
+static int luaT_mt__newindex(lua_State *L)
+{
+  if(!lua_getmetatable(L, 1))
+    luaL_error(L, "critical internal indexing error: no metatable found");
+
+  if(!lua_istable(L, -1))
+    luaL_error(L, "critical internal indexing error: not a metatable");
+
+  /* test for __newindex__ method first */
+  lua_getfield(L, -1, "__newindex__");
+  if(!lua_isnil(L, -1))
+  {
+    int result;
+
+    if(!lua_isfunction(L, -1))
+      luaL_error(L, "critical internal indexing error: __newindex__ is not a function");
+
+    lua_pushvalue(L, 1);
+    lua_pushvalue(L, 2);
+    lua_pushvalue(L, 3);
+
+    lua_call(L, 3, 1); /* DEBUG: risque: faut vraiment retourner qqch */
+
+    result = lua_toboolean(L, -1);
+    lua_pop(L, 1);
+
+    if(result)
+      return 0;
+  }
+  else
+    lua_pop(L, 1); /* remove nil __newindex__ on the stack */
+
+  lua_pop(L, 1);    /* pop the metatable */
+  if(lua_istable(L, 1))
+    lua_rawset(L, 1);
+  else
+    luaL_error(L, "the class %s cannot be indexed", luaT_typename(L, 1));
+
+  return 0;
+}
+
+/* note: check dans metatable pour ca, donc necessaire */
+#define MT_DECLARE_OPERATOR(NAME, NIL_BEHAVIOR)                     \
+  int luaT_mt__##NAME(lua_State *L)                                 \
+  {                                                                 \
+    if(!lua_getmetatable(L, 1))                                     \
+      luaL_error(L, "internal error in __" #NAME ": no metatable"); \
+                                                                    \
+    lua_getfield(L, -1, "__" #NAME "__");                           \
+    if(lua_isnil(L, -1))                                                \
+    {                                                                   \
+      NIL_BEHAVIOR;                                                     \
+    }                                                                   \
+    else                                                                \
+    {                                                                   \
+      if(lua_isfunction(L, -1))                                         \
+      {                                                                 \
+        lua_insert(L, 1); /* insert function */                         \
+        lua_pop(L, 1); /* remove metatable */                           \
+        lua_call(L, lua_gettop(L)-1, LUA_MULTRET); /* we return the result of the call */ \
+        return lua_gettop(L);                                           \
+      }                                                                 \
+      /* we return the thing the user left in __tostring__ */           \
+    }                                                                   \
+    return 0;                                                           \
+  }
+
+MT_DECLARE_OPERATOR(tostring,
+                    lua_pushstring(L, luaT_typename(L, 1));
+                    return 1;)
+MT_DECLARE_OPERATOR(add, luaL_error(L, "%s has no addition operator", luaT_typename(L, 1)))
+MT_DECLARE_OPERATOR(sub, luaL_error(L, "%s has no substraction operator", luaT_typename(L, 1)))
+MT_DECLARE_OPERATOR(mul, luaL_error(L, "%s has no multiplication operator", luaT_typename(L, 1)))
+MT_DECLARE_OPERATOR(div, luaL_error(L, "%s has no division operator", luaT_typename(L, 1)))
+MT_DECLARE_OPERATOR(mod, luaL_error(L, "%s has no modulo operator", luaT_typename(L, 1)))
+MT_DECLARE_OPERATOR(pow, luaL_error(L, "%s has no power operator", luaT_typename(L, 1)))
+MT_DECLARE_OPERATOR(unm, luaL_error(L, "%s has no negation operator", luaT_typename(L, 1)))
+MT_DECLARE_OPERATOR(concat, luaL_error(L, "%s has no concat operator", luaT_typename(L, 1)))
+MT_DECLARE_OPERATOR(len, luaL_error(L, "%s has no length operator", luaT_typename(L, 1)))
+MT_DECLARE_OPERATOR(eq,
+                    lua_settop(L, 2);
+                    lua_pushcfunction(L, luaT_lua_isequal);
+                    lua_insert(L, 1);
+                    lua_call(L, 2, 1);
+                    return 1;)
+MT_DECLARE_OPERATOR(lt, luaL_error(L, "%s has no lower than operator", luaT_typename(L, 1)))
+MT_DECLARE_OPERATOR(le, luaL_error(L, "%s has no lower or equal than operator", luaT_typename(L, 1)))
+MT_DECLARE_OPERATOR(call, luaL_error(L, "%s has no call operator", luaT_typename(L, 1)))
+
+
+/* constructor metatable methods */
+int luaT_cmt__call(lua_State *L)
+{
+  if(!lua_istable(L, 1))
+    luaL_error(L, "internal error in __call: not a constructor table");
+
+  if(!lua_getmetatable(L, 1))
+    luaL_error(L, "internal error in __call: no metatable available");
+
+  lua_pushstring(L, "__new");
+  lua_rawget(L, -2);
+
+  if(lua_isnil(L, -1))
+    luaL_error(L, "no constructor available");
+
+  lua_remove(L, 1); /* remove constructor atable */
+  lua_insert(L, 1); /* insert constructor */
+  lua_pop(L, 1);    /* remove fancy metatable */
+
+  lua_call(L, lua_gettop(L)-1, LUA_MULTRET);
+  return lua_gettop(L);
+}
+
+int luaT_cmt__newindex(lua_State *L)
+{
+  if(!lua_istable(L, 1))
+    luaL_error(L, "internal error in __newindex: not a constructor table");
+
+  if(!lua_getmetatable(L, 1))
+    luaL_error(L, "internal error in __newindex: no metatable available");
+
+  lua_pushstring(L, "__metatable");
+  lua_rawget(L, -2);
+
+  if(!lua_istable(L, -1))
+    luaL_error(L, "internal error in __newindex: no metaclass available");
+
+  lua_insert(L, 2);
+  lua_pop(L, 1); /* remove the metatable over the constructor table */
+
+  lua_rawset(L, -3);
+
+  return 0;
+}
+
+/******************** deprecated functions ********************/
+int luaT_pushmetaclass(lua_State *L, const char *tname)
+{
+  return luaT_pushmetatable(L, tname);
+}
+
+const char* luaT_id(lua_State *L, int ud)
+{
+  return luaT_typename(L, ud);
+}
+
+const char* luaT_id2typename(lua_State *L, const char *id)
+{
+  return id;
+}
+
+const char* luaT_typename2id(lua_State *L, const char *tname)
+{
+  return luaT_typenameid(L, tname);
+}
+
+int luaT_getmetaclass(lua_State *L, int index)
+{
+  return lua_getmetatable(L, index);
+}
+
+const char* luaT_checktypename2id(lua_State *L, const char *tname)
+{
+  const char* id = luaT_typenameid(L, tname);
+  if(!id)
+    luaL_error(L, "unknown class <%s>", tname);
+  return id;
+}
+
+void luaT_registeratid(lua_State *L, const struct luaL_Reg *methods, const char *id)
+{
+  luaT_registeratname(L, methods, id);
+}
+
+/**************************************************************/