/* lua-utils.c * * Copyright (C) 2009 Francesco Abbate * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3 of the License, or (at * your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include #include #include #include #include "lua-utils.h" #include "gs-types.h" static char const * const CACHE_FIELD_NAME = "__cache"; const struct luaL_Reg * mlua_find_method (const struct luaL_Reg *p, const char *key) { for (/* */; p->name; p++) { if (strcmp (p->name, key) == 0) return p; } return NULL; } int mlua_get_property (lua_State *L, const struct luaL_Reg *p, bool use_cache) { int rval; bool cache_is_new = false; if (! use_cache) return p->func (L); lua_getfenv (L, 1); lua_getfield (L, -1, CACHE_FIELD_NAME); if (lua_isnil (L, -1)) { lua_pop (L, 1); lua_newtable (L); lua_pushvalue (L, -1); lua_setfield (L, -3, CACHE_FIELD_NAME); cache_is_new = true; } if (! cache_is_new) { lua_getfield (L, -1, p->name); if (! lua_isnil (L, -1)) return 1; lua_pop (L, 1); } rval = p->func (L); if (rval == 1) { lua_pushvalue (L, -1); lua_setfield (L, -3, p->name); return 1; } return rval; } int mlua_index_with_properties (lua_State *L, const struct luaL_Reg *properties, const struct luaL_Reg *methods, bool use_cache) { char const * key; const struct luaL_Reg *reg; key = lua_tostring (L, 2); if (key == NULL) return 0; reg = mlua_find_method (methods, key); if (reg) { lua_pushcfunction (L, reg->func); return 1; } reg = mlua_find_method (properties, key); if (reg) { return mlua_get_property (L, reg, use_cache); } return 0; } int mlua_newindex_with_properties (lua_State *L, const struct luaL_Reg *properties) { char const * key; const struct luaL_Reg *reg; key = lua_tostring (L, 2); if (key == NULL) return 0; reg = mlua_find_method (properties, key); if (reg) { lua_remove (L, 2); return reg->func (L); } return luaL_error (L, "invalid property for %s object", full_type_name (L, 1)); } lua_Number mlua_named_optnumber (lua_State *L, int index, const char *key, lua_Number default_value) { lua_Number r; lua_getfield (L, index, key); r = luaL_optnumber (L, -1, default_value); lua_pop (L, 1); return r; } const char * mlua_named_optstring (lua_State *L, int index, const char *key, const char * default_value) { const char * r; lua_getfield (L, index, key); r = luaL_optstring (L, -1, default_value); lua_pop (L, 1); return r; } lua_Number mlua_named_number (lua_State *L, int index, const char *key) { lua_Number r; lua_getfield (L, index, key); if (! lua_isnumber (L, -1)) luaL_error (L, "number expected"); r = lua_tonumber (L, -1); lua_pop (L, 1); return r; } const char * mlua_named_string (lua_State *L, int index, const char *key) { const char * r; lua_getfield (L, index, key); if (! lua_isstring (L, -1)) luaL_error (L, "string expected"); r = lua_tostring (L, -1); lua_pop (L, 1); return r; }