--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib/lua_func.c	Thu May 28 01:17:36 2009 +0300
@@ -0,0 +1,207 @@
+#include "lua_func.h"
+#include "error.h"
+
+#include <lua5.1/lauxlib.h>
+
+/**
+ * Pushes onto the stack the value at t[i]
+ */
+static void lua_getindex (lua_State *L, int t, int i)
+{
+    lua_pushinteger(L, i);
+    lua_gettable(L, t);
+}
+
+/**
+ * Pushes onto the stack either:
+ *  * the value at t[name]
+ *  * the value at t[index]
+ *
+ *  Returns the new index, or 0, if neither could be found
+ */
+static int lua_arg_lookup (lua_State *L, int t, const char *name, int index)
+{
+    // try name
+    lua_getfield(L, t, name);
+
+    if (!lua_isnil(L, -1))
+        return lua_gettop(L);
+    else
+        lua_pop(L, 1);
+    
+    // try index
+    lua_getindex(L, t, index);
+    
+    if (!lua_isnil(L, -1))
+        return lua_gettop(L);
+
+    else
+        lua_pop(L, 1);
+    
+    // not found
+    return 0;
+}
+
+static const char *_lua_arg_string (lua_State *L, int index, const char *name, const char *def)
+{
+    const char *value;
+
+    // use default?
+    if (lua_isnoneornil(L, index) && def != (const char *) LUA_ARG_REQUIRED)
+        return def;
+    
+    // value given?
+    if ((value = lua_tostring(L, index)))
+        return value;
+   
+    // error
+    luaL_error(L, "missing value for required string argument <%d:%s>", index, name); return NULL;
+}
+
+static bool _lua_arg_bool (lua_State *L, int index, const char *name, int def)
+{
+    (void) name;
+
+    // use default?
+    if (lua_isnoneornil(L, index) && def != LUA_ARG_REQUIRED)
+        return def;
+   
+    // value given
+    return lua_toboolean(L, index);
+}
+
+static long _lua_arg_int (lua_State *L, int index, const char *name, long def)
+{
+    (void) name;
+
+    // use default?
+    if (lua_isnoneornil(L, index) && def != LUA_ARG_REQUIRED)
+        return def;
+   
+    // conver to integer
+    // XXX: check compatibility?
+    return lua_tointeger(L, index);
+}
+
+static void * _lua_arg_obj (lua_State *L, int index, const struct lua_type *type, bool optional)
+{
+    // not given?
+    if (!lua_isnoneornil(L, index))
+        return lua_type_get(L, type, index);
+
+    if (optional)
+        return NULL;
+    
+    luaL_error(L, "missing value for required object argument <%d:%s>", index, type->name);
+    return NULL;
+}
+
+/**
+ * Look up the arg index to use for the given index/name.
+ *
+ * If no value is found for the corresponding index, returns zero.
+ */
+static int lua_arg_index (lua_State *L, int nargs, int index, const char *name)
+{
+    // lookup from table?
+    if (nargs == 2 && lua_istable(L, 2) && name) {
+        // push the value from the named field onto the stack
+        lua_getfield(L, 2, name);
+        
+        // no named field?
+        if (lua_isnil(L, -1)) {
+            lua_pop(L, 1);
+
+            lua_getindex(L, 2, index - 1);
+        }
+
+        // no index field?
+        if (lua_isnil(L, -1)) {
+            lua_pop(L, 1);
+
+            return 0;
+        }
+        
+        // found either a named or indexed arg
+        return lua_gettop(L);
+
+    } else if (index <= nargs) {
+        // use the same index
+        return index;
+
+    } else {
+        // no index
+        return 0;
+    }
+}
+
+const char *lua_arg_string (lua_State *L, int nargs, int index, const char *name, const char *def)
+{
+    return _lua_arg_string(L, lua_arg_index(L, nargs, index, name), name, def);
+}
+
+bool lua_arg_bool (lua_State *L, int nargs, int index, const char *name, int def)
+{
+    return _lua_arg_bool(L, lua_arg_index(L, nargs, index, name), name, def);    
+}
+
+void* lua_arg_obj (lua_State *L, int nargs, int index, const struct lua_type *type, bool optional)
+{
+    return _lua_arg_obj(L, lua_arg_index(L, nargs, index, NULL), type, optional);
+}
+
+long lua_arg_int (lua_State *L, int nargs, int index, const char *name, long def)
+{
+    return _lua_arg_int(L, lua_arg_index(L, nargs, index, name), name, def);
+}
+
+void lua_args_parse (lua_State *L, const struct lua_func *func, void **obj_ptr, ...)
+{
+    int argidx = 1, argtbl = 0, idx;
+    const struct lua_func_arg *arg;
+    va_list vargs;
+
+    // first, the obj argument
+    if (func->type)
+        *obj_ptr = lua_type_get(L, func->type, argidx++);
+
+    // were we given a table of arguments?
+    if (lua_istable(L, argidx))
+        argtbl = argidx++;
+
+    // parse the args
+    va_start(vargs, obj_ptr);
+
+    for (arg = func->args, idx = 1; arg->name && arg->type; arg++, idx++) {
+        int index;
+
+        // map index
+        if (!argtbl)
+            // direct
+            index = argidx++;
+        
+        else
+            // lookup from table
+            index = lua_arg_lookup(L, argtbl, arg->name, idx);
+        
+        // apply
+        switch (arg->type) {
+            case LUA_ARG_STRING:
+                *va_arg(vargs, const char **) = _lua_arg_string(L, index, arg->name, arg->def.string);
+                break;
+
+            case LUA_ARG_BOOL:
+                *va_arg(vargs, bool *) = _lua_arg_bool(L, index, arg->name, arg->def.boolean);
+                break;
+            
+            case LUA_ARG_INT:
+                *va_arg(vargs, long *) = _lua_arg_int(L, index, arg->name, arg->def.integer);
+                break;
+
+            default:
+                NOT_REACHED();
+        };
+    }
+
+    va_end(vargs);
+}