lua-utils.c - gsl-shell.git - gsl-shell

/* 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 <lua.h>
#include <lauxlib.h>
#include <string.h>
#include <stdio.h>
#include "lua-utils.h"
#include "gs-types.h"
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;
}
void
mlua_null_cache (lua_State *L, int index)
{
 lua_getfenv (L, index);
 lua_pushnil (L);
 lua_setfield (L, -2, CACHE_FIELD_NAME);
 lua_pop (L, 1);
}
int
mlua_index_with_properties (lua_State *L, const struct luaL_Reg *properties,
			 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 (properties, key);
 if (reg)
 {
 return mlua_get_property (L, reg, use_cache);
 }
 lua_getmetatable (L, 1);
 lua_replace (L, 1);
 lua_gettable (L, 1);
 return 1;
}
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));
}
void
mlua_check_field_type (lua_State *L, int index, const char *key, int type,
		 const char *error_msg)
{
 lua_getfield (L, index, key);
 if (lua_type (L, -1) != type)
 {
 if (error_msg)
	luaL_error (L, "field \"%s\", ", key, error_msg);
 else
	luaL_error (L, "field \"%s\" should be an %s", key, 
		 lua_typename (L, type));
 }
 lua_pop (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;
}
void
mlua_fenv_set (lua_State *L, int index, int fenv_index)
{
 lua_getfenv (L, index);
 lua_insert (L, -2);
 lua_rawseti (L, -2, fenv_index);
 lua_pop (L, 1);
}
void
mlua_fenv_get (lua_State *L, int index, int fenv_index)
{
 lua_getfenv (L, index);
 lua_rawgeti (L, -1, fenv_index);
 lua_remove (L, -2);
}
void
mlua_fenv_addref (lua_State *L, int refindex)
{
 int n;
 lua_getfenv (L, -1);
 n = lua_objlen (L, -1);
 lua_pushvalue (L, refindex);
 lua_rawseti (L, -2, n+1);
 lua_pop (L, 1);
}
void
mlua_set_fenv_ref (lua_State *L, int refindex)
{
 int n;
 lua_newtable (L);
 lua_pushvalue (L, refindex);
 lua_rawseti (L, -2, 1);
 lua_setfenv (L, -2);
}
void
prepare_window_ref_table (lua_State *L)
{
 lua_newtable (L);
 lua_pushinteger (L, 0);
 lua_setfield (L, -2, "N");
 lua_setfield (L, LUA_REGISTRYINDEX, "GSL.windows");
}
int 
mlua_window_ref(lua_State *L, int index)
{
 int n;
 lua_getfield (L, LUA_REGISTRYINDEX, "GSL.windows");
 lua_getfield (L, -1, "N");
 n = lua_tointeger (L, -1);
 lua_pushinteger (L, n+1);
 lua_remove (L, -2);
 lua_setfield (L, -2, "N");
 lua_pushvalue (L, index);
 lua_rawseti (L, -2, n+1);
 lua_pop (L, 1);
 return n+1;
}
void
mlua_window_unref(lua_State *L, int id)
{
 lua_getfield (L, LUA_REGISTRYINDEX, "GSL.windows");
 lua_pushnil (L);
 lua_rawseti (L, -2, id);
 lua_pop (L, 1);
}