--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/auxiliar.c	Tue Aug 26 18:40:01 2008 -0700
@@ -0,0 +1,149 @@
+/*=========================================================================*\
+* Auxiliar routines for class hierarchy manipulation
+* LuaSocket toolkit
+*
+* RCS ID: $Id: auxiliar.c,v 1.14 2005/10/07 04:40:59 diego Exp $
+\*=========================================================================*/
+#include <string.h>
+#include <stdio.h>
+
+#include "auxiliar.h"
+
+/*=========================================================================*\
+* Exported functions
+\*=========================================================================*/
+/*-------------------------------------------------------------------------*\
+* Initializes the module
+\*-------------------------------------------------------------------------*/
+int auxiliar_open(lua_State *L) {
+    (void) L;
+    return 0;
+}
+
+/*-------------------------------------------------------------------------*\
+* Creates a new class with given methods
+* Methods whose names start with __ are passed directly to the metatable.
+\*-------------------------------------------------------------------------*/
+void auxiliar_newclass(lua_State *L, const char *classname, luaL_reg *func) {
+    luaL_newmetatable(L, classname); /* mt */
+    /* create __index table to place methods */
+    lua_pushstring(L, "__index");    /* mt,"__index" */
+    lua_newtable(L);                 /* mt,"__index",it */ 
+    /* put class name into class metatable */
+    lua_pushstring(L, "class");      /* mt,"__index",it,"class" */
+    lua_pushstring(L, classname);    /* mt,"__index",it,"class",classname */
+    lua_rawset(L, -3);               /* mt,"__index",it */
+    /* pass all methods that start with _ to the metatable, and all others
+     * to the index table */
+    for (; func->name; func++) {     /* mt,"__index",it */
+        lua_pushstring(L, func->name);
+        lua_pushcfunction(L, func->func);
+        lua_rawset(L, func->name[0] == '_' ? -5: -3);
+    }
+    lua_rawset(L, -3);               /* mt */
+    lua_pop(L, 1);
+}
+
+/*-------------------------------------------------------------------------*\
+* Prints the value of a class in a nice way
+\*-------------------------------------------------------------------------*/
+int auxiliar_tostring(lua_State *L) {
+    char buf[32];
+    if (!lua_getmetatable(L, 1)) goto error;
+    lua_pushstring(L, "__index");
+    lua_gettable(L, -2);
+    if (!lua_istable(L, -1)) goto error;
+    lua_pushstring(L, "class");
+    lua_gettable(L, -2);
+    if (!lua_isstring(L, -1)) goto error;
+    sprintf(buf, "%p", lua_touserdata(L, 1));
+    lua_pushfstring(L, "%s: %s", lua_tostring(L, -1), buf);
+    return 1;
+error:
+    lua_pushstring(L, "invalid object passed to 'auxiliar.c:__tostring'");
+    lua_error(L);
+    return 1;
+}
+
+/*-------------------------------------------------------------------------*\
+* Insert class into group
+\*-------------------------------------------------------------------------*/
+void auxiliar_add2group(lua_State *L, const char *classname, const char *groupname) {
+    luaL_getmetatable(L, classname);
+    lua_pushstring(L, groupname);
+    lua_pushboolean(L, 1);
+    lua_rawset(L, -3);
+    lua_pop(L, 1);
+}
+
+/*-------------------------------------------------------------------------*\
+* Make sure argument is a boolean
+\*-------------------------------------------------------------------------*/
+int auxiliar_checkboolean(lua_State *L, int objidx) {
+    if (!lua_isboolean(L, objidx))
+        luaL_typerror(L, objidx, lua_typename(L, LUA_TBOOLEAN));
+    return lua_toboolean(L, objidx);
+}
+
+/*-------------------------------------------------------------------------*\
+* Return userdata pointer if object belongs to a given class, abort with 
+* error otherwise
+\*-------------------------------------------------------------------------*/
+void *auxiliar_checkclass(lua_State *L, const char *classname, int objidx) {
+    void *data = auxiliar_getclassudata(L, classname, objidx);
+    if (!data) {
+        char msg[45];
+        sprintf(msg, "%.35s expected", classname);
+        luaL_argerror(L, objidx, msg);
+    }
+    return data;
+}
+
+/*-------------------------------------------------------------------------*\
+* Return userdata pointer if object belongs to a given group, abort with 
+* error otherwise
+\*-------------------------------------------------------------------------*/
+void *auxiliar_checkgroup(lua_State *L, const char *groupname, int objidx) {
+    void *data = auxiliar_getgroupudata(L, groupname, objidx);
+    if (!data) {
+        char msg[45];
+        sprintf(msg, "%.35s expected", groupname);
+        luaL_argerror(L, objidx, msg);
+    }
+    return data;
+}
+
+/*-------------------------------------------------------------------------*\
+* Set object class
+\*-------------------------------------------------------------------------*/
+void auxiliar_setclass(lua_State *L, const char *classname, int objidx) {
+    luaL_getmetatable(L, classname);
+    if (objidx < 0) objidx--;
+    lua_setmetatable(L, objidx);
+}
+
+/*-------------------------------------------------------------------------*\
+* Get a userdata pointer if object belongs to a given group. Return NULL 
+* otherwise
+\*-------------------------------------------------------------------------*/
+void *auxiliar_getgroupudata(lua_State *L, const char *groupname, int objidx) {
+    if (!lua_getmetatable(L, objidx))
+        return NULL;
+    lua_pushstring(L, groupname);
+    lua_rawget(L, -2);
+    if (lua_isnil(L, -1)) {
+        lua_pop(L, 2);
+        return NULL;
+    } else {
+        lua_pop(L, 2);
+        return lua_touserdata(L, objidx);
+    }
+}
+
+/*-------------------------------------------------------------------------*\
+* Get a userdata pointer if object belongs to a given class. Return NULL 
+* otherwise
+\*-------------------------------------------------------------------------*/
+void *auxiliar_getclassudata(lua_State *L, const char *classname, int objidx) {
+    return luaL_checkudata(L, objidx, classname);
+}