From 40cfb0691e233e164efee27873454cf457255a47 Mon Sep 17 00:00:00 2001 From: Roberto Ierusalimschy Date: Tue, 18 Mar 2003 09:25:32 -0300 Subject: new auxiliary functions for `type' manipulation --- lauxlib.c | 54 ++++++++++++++++++++++++++++++++++++++++-------------- lauxlib.h | 11 +++++++---- liolib.c | 30 +++++++++--------------------- 3 files changed, 56 insertions(+), 39 deletions(-) diff --git a/lauxlib.c b/lauxlib.c index 8fb01bc7..291d232d 100644 --- a/lauxlib.c +++ b/lauxlib.c @@ -1,5 +1,5 @@ /* -** $Id: lauxlib.c,v 1.94 2003/02/11 09:44:38 roberto Exp roberto $ +** $Id: lauxlib.c,v 1.95 2003/02/11 15:32:31 roberto Exp roberto $ ** Auxiliary functions for building Lua libraries ** See Copyright Notice in lua.h */ @@ -103,6 +103,45 @@ LUALIB_API int luaL_findstring (const char *name, const char *const list[]) { } +LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) { + lua_pushstring(L, tname); + lua_rawget(L, LUA_REGISTRYINDEX); /* get registry.name */ + if (!lua_isnil(L, -1)) /* name already in use? */ + return 0; /* leave previous value on top, but return 0 */ + lua_pop(L, 1); + lua_newtable(L); /* create metatable */ + lua_pushstring(L, tname); + lua_pushvalue(L, -2); + lua_rawset(L, LUA_REGISTRYINDEX); /* registry.name = metatable */ + lua_pushvalue(L, -1); + lua_pushstring(L, tname); + lua_rawset(L, LUA_REGISTRYINDEX); /* registry[metatable] = name */ + return 1; +} + + +LUALIB_API void luaL_getmetatable (lua_State *L, const char *tname) { + lua_pushstring(L, tname); + lua_rawget(L, LUA_REGISTRYINDEX); +} + + +LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) { + const char *tn; + if (!lua_getmetatable(L, ud)) return NULL; /* no metatable? */ + lua_rawget(L, LUA_REGISTRYINDEX); /* get registry[metatable] */ + tn = lua_tostring(L, -1); + if (tn && (strcmp(tn, tname) == 0)) { + lua_pop(L, 1); + return lua_touserdata(L, ud); + } + else { + lua_pop(L, 1); + return NULL; + } +} + + LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *mes) { if (!lua_checkstack(L, space)) luaL_error(L, "stack overflow (%s)", mes); @@ -121,19 +160,6 @@ LUALIB_API void luaL_checkany (lua_State *L, int narg) { } -LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) { - if (!lua_getmetatable(L, ud)) return NULL; /* no metatable? */ - lua_pushstring(L, tname); - lua_rawget(L, LUA_REGISTRYINDEX); - if (!lua_rawequal(L, -1, -2)) { - lua_pop(L, 2); - return NULL; - } - lua_pop(L, 2); - return lua_touserdata(L, ud); -} - - LUALIB_API const char *luaL_checklstring (lua_State *L, int narg, size_t *len) { const char *s = lua_tostring(L, narg); if (!s) tag_error(L, narg, LUA_TSTRING); diff --git a/lauxlib.h b/lauxlib.h index cdb313fd..5969cbf8 100644 --- a/lauxlib.h +++ b/lauxlib.h @@ -1,5 +1,5 @@ /* -** $Id: lauxlib.h,v 1.57 2003/01/27 13:46:16 roberto Exp roberto $ +** $Id: lauxlib.h,v 1.58 2003/02/11 15:32:31 roberto Exp roberto $ ** Auxiliary functions for building Lua libraries ** See Copyright Notice in lua.h */ @@ -16,7 +16,7 @@ #ifndef LUALIB_API -#define LUALIB_API extern +#define LUALIB_API LUA_API #endif @@ -33,7 +33,6 @@ LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *e); LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *e); LUALIB_API int luaL_typerror (lua_State *L, int narg, const char *tname); LUALIB_API int luaL_argerror (lua_State *L, int numarg, const char *extramsg); -LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname); LUALIB_API const char *luaL_checklstring (lua_State *L, int numArg, size_t *l); LUALIB_API const char *luaL_optlstring (lua_State *L, int numArg, const char *def, size_t *l); @@ -44,6 +43,10 @@ LUALIB_API void luaL_checkstack (lua_State *L, int sz, const char *msg); LUALIB_API void luaL_checktype (lua_State *L, int narg, int t); LUALIB_API void luaL_checkany (lua_State *L, int narg); +LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname); +LUALIB_API void luaL_getmetatable (lua_State *L, const char *tname); +LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname); + LUALIB_API void luaL_where (lua_State *L, int lvl); LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...); @@ -115,7 +118,7 @@ LUALIB_API void luaL_pushresult (luaL_Buffer *B); /* -** Compatibility macros +** Compatibility macros and functions */ LUALIB_API int lua_dofile (lua_State *L, const char *filename); diff --git a/liolib.c b/liolib.c index b4b8c9b9..ad5b93d1 100644 --- a/liolib.c +++ b/liolib.c @@ -1,5 +1,5 @@ /* -** $Id: liolib.c,v 2.36 2003/03/14 19:00:16 roberto Exp roberto $ +** $Id: liolib.c,v 2.37 2003/03/14 19:08:11 roberto Exp roberto $ ** Standard I/O (and system) library ** See Copyright Notice in lua.h */ @@ -87,21 +87,15 @@ static int pushresult (lua_State *L, int i, const char *filename) { static FILE **topfile (lua_State *L, int findex) { - FILE **f = (FILE **)lua_touserdata(L, findex); - if (f == NULL || !lua_getmetatable(L, findex) || - !lua_rawequal(L, -1, lua_upvalueindex(1))) { - luaL_argerror(L, findex, "bad file"); - } - lua_pop(L, 1); + FILE **f = (FILE **)luaL_checkudata(L, findex, FILEHANDLE); + if (f == NULL) luaL_argerror(L, findex, "bad file"); return f; } static int io_type (lua_State *L) { - FILE **f = (FILE **)lua_touserdata(L, 1); - if (f == NULL || !lua_getmetatable(L, 1) || - !lua_rawequal(L, -1, lua_upvalueindex(1))) - lua_pushnil(L); + FILE **f = (FILE **)luaL_checkudata(L, 1, FILEHANDLE); + if (f == NULL) lua_pushnil(L); else if (*f == NULL) lua_pushliteral(L, "closed file"); else @@ -127,8 +121,7 @@ static FILE *tofile (lua_State *L, int findex) { static FILE **newfile (lua_State *L) { FILE **pf = (FILE **)lua_newuserdata(L, sizeof(FILE *)); *pf = NULL; /* file handle is currently `closed' */ - lua_pushliteral(L, FILEHANDLE); - lua_rawget(L, LUA_REGISTRYINDEX); + luaL_getmetatable(L, FILEHANDLE); lua_setmetatable(L, -2); return pf; } @@ -527,15 +520,12 @@ static const luaL_reg flib[] = { static void createmeta (lua_State *L) { - lua_pushliteral(L, FILEHANDLE); - lua_newtable(L); /* push new metatable for file handles */ + luaL_newmetatable(L, FILEHANDLE); /* create new metatable for file handles */ /* file methods */ lua_pushliteral(L, "__index"); lua_pushvalue(L, -2); /* push metatable */ lua_rawset(L, -3); /* metatable.__index = metatable */ - lua_pushvalue(L, -1); /* push metatable (will be upvalue for library) */ - luaL_openlib(L, NULL, flib, 1); - lua_rawset(L, LUA_REGISTRYINDEX); /* registry.FILEHANDLE = metatable */ + luaL_openlib(L, NULL, flib, 0); } /* }====================================================== */ @@ -748,10 +738,8 @@ static const luaL_reg syslib[] = { LUALIB_API int luaopen_io (lua_State *L) { - createmeta(L); luaL_openlib(L, LUA_OSLIBNAME, syslib, 0); - lua_pushliteral(L, FILEHANDLE); - lua_rawget(L, LUA_REGISTRYINDEX); + createmeta(L); lua_pushvalue(L, -1); luaL_openlib(L, LUA_IOLIBNAME, iolib, 1); /* put predefined file handles into `io' table */ -- cgit v1.2.3-55-g6feb