xref: /vim-8.2.3635/src/if_lua.c (revision fc65cabb)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Lua interface by Luis Carvalho
6  *
7  * Do ":help uganda"  in Vim to read copying and usage conditions.
8  * Do ":help credits" in Vim to see a list of people who contributed.
9  * See README.txt for an overview of the Vim source code.
10  */
11 
12 #include "vim.h"
13 
14 #include <lua.h>
15 #include <lualib.h>
16 #include <lauxlib.h>
17 
18 /* Only do the following when the feature is enabled.  Needed for "make
19  * depend". */
20 #if defined(FEAT_LUA) || defined(PROTO)
21 
22 #define LUAVIM_CHUNKNAME "vim chunk"
23 #define LUAVIM_NAME "vim"
24 #define LUAVIM_EVALNAME "luaeval"
25 #define LUAVIM_EVALHEADER "local _A=select(1,...) return "
26 
27 typedef buf_T *luaV_Buffer;
28 typedef win_T *luaV_Window;
29 typedef dict_T *luaV_Dict;
30 typedef list_T *luaV_List;
31 typedef struct {
32     typval_T	tv;	// funcref
33     typval_T	args;
34     dict_T	*self;	// selfdict
35 } luaV_Funcref;
36 typedef void (*msgfunc_T)(char_u *);
37 
38 static const char LUAVIM_DICT[] = "dict";
39 static const char LUAVIM_LIST[] = "list";
40 static const char LUAVIM_FUNCREF[] = "funcref";
41 static const char LUAVIM_BUFFER[] = "buffer";
42 static const char LUAVIM_WINDOW[] = "window";
43 static const char LUAVIM_FREE[] = "luaV_free";
44 static const char LUAVIM_LUAEVAL[] = "luaV_luaeval";
45 static const char LUAVIM_SETREF[] = "luaV_setref";
46 
47 /* most functions are closures with a cache table as first upvalue;
48  * get/setudata manage references to vim userdata in cache table through
49  * object pointers (light userdata) */
50 #define luaV_getudata(L, v) \
51     lua_pushlightuserdata((L), (void *) (v)); \
52     lua_rawget((L), lua_upvalueindex(1))
53 #define luaV_setudata(L, v) \
54     lua_pushlightuserdata((L), (void *) (v)); \
55     lua_pushvalue((L), -2); \
56     lua_rawset((L), lua_upvalueindex(1))
57 #define luaV_getfield(L, s) \
58     lua_pushlightuserdata((L), (void *)(s)); \
59     lua_rawget((L), LUA_REGISTRYINDEX)
60 #define luaV_checksandbox(L) \
61     if (sandbox) luaL_error((L), "not allowed in sandbox")
62 #define luaV_msg(L) luaV_msgfunc((L), (msgfunc_T) msg)
63 #define luaV_emsg(L) luaV_msgfunc((L), (msgfunc_T) emsg)
64 #define luaV_checktypval(L, a, v, msg) \
65     do { \
66         if (luaV_totypval(L, a, v) == FAIL) \
67 	    luaL_error(L, msg ": cannot convert value"); \
68     } while (0)
69 
70 static luaV_List *luaV_pushlist(lua_State *L, list_T *lis);
71 static luaV_Dict *luaV_pushdict(lua_State *L, dict_T *dic);
72 static luaV_Funcref *luaV_pushfuncref(lua_State *L, typval_T *tv);
73 
74 #if LUA_VERSION_NUM <= 501
75 #define luaV_openlib(L, l, n) luaL_openlib(L, NULL, l, n)
76 #define luaL_typeerror luaL_typerror
77 #else
78 #define luaV_openlib luaL_setfuncs
79 #endif
80 
81 #ifdef DYNAMIC_LUA
82 
83 #ifndef WIN3264
84 # include <dlfcn.h>
85 # define HANDLE void*
86 # define load_dll(n) dlopen((n), RTLD_LAZY|RTLD_GLOBAL)
87 # define symbol_from_dll dlsym
88 # define close_dll dlclose
89 #else
90 # define load_dll vimLoadLib
91 # define symbol_from_dll GetProcAddress
92 # define close_dll FreeLibrary
93 #endif
94 
95 /* lauxlib */
96 #if LUA_VERSION_NUM <= 501
97 #define luaL_register dll_luaL_register
98 #define luaL_prepbuffer dll_luaL_prepbuffer
99 #define luaL_openlib dll_luaL_openlib
100 #define luaL_typerror dll_luaL_typerror
101 #define luaL_loadfile dll_luaL_loadfile
102 #define luaL_loadbuffer dll_luaL_loadbuffer
103 #else
104 #define luaL_prepbuffsize dll_luaL_prepbuffsize
105 #define luaL_setfuncs dll_luaL_setfuncs
106 #define luaL_loadfilex dll_luaL_loadfilex
107 #define luaL_loadbufferx dll_luaL_loadbufferx
108 #define luaL_argerror dll_luaL_argerror
109 #endif
110 #define luaL_checkany dll_luaL_checkany
111 #define luaL_checklstring dll_luaL_checklstring
112 #define luaL_checkinteger dll_luaL_checkinteger
113 #define luaL_optinteger dll_luaL_optinteger
114 #define luaL_checktype dll_luaL_checktype
115 #define luaL_error dll_luaL_error
116 #define luaL_newstate dll_luaL_newstate
117 #define luaL_buffinit dll_luaL_buffinit
118 #define luaL_addlstring dll_luaL_addlstring
119 #define luaL_pushresult dll_luaL_pushresult
120 /* lua */
121 #if LUA_VERSION_NUM <= 501
122 #define lua_tonumber dll_lua_tonumber
123 #define lua_tointeger dll_lua_tointeger
124 #define lua_call dll_lua_call
125 #define lua_pcall dll_lua_pcall
126 #else
127 #define lua_tonumberx dll_lua_tonumberx
128 #define lua_tointegerx dll_lua_tointegerx
129 #define lua_callk dll_lua_callk
130 #define lua_pcallk dll_lua_pcallk
131 #define lua_getglobal dll_lua_getglobal
132 #define lua_setglobal dll_lua_setglobal
133 #endif
134 #if LUA_VERSION_NUM <= 502
135 #define lua_replace dll_lua_replace
136 #define lua_remove dll_lua_remove
137 #endif
138 #if LUA_VERSION_NUM >= 503
139 #define lua_rotate dll_lua_rotate
140 #define lua_copy dll_lua_copy
141 #endif
142 #define lua_typename dll_lua_typename
143 #define lua_close dll_lua_close
144 #define lua_gettop dll_lua_gettop
145 #define lua_settop dll_lua_settop
146 #define lua_pushvalue dll_lua_pushvalue
147 #define lua_isnumber dll_lua_isnumber
148 #define lua_isstring dll_lua_isstring
149 #define lua_type dll_lua_type
150 #define lua_rawequal dll_lua_rawequal
151 #define lua_toboolean dll_lua_toboolean
152 #define lua_tolstring dll_lua_tolstring
153 #define lua_touserdata dll_lua_touserdata
154 #define lua_pushnil dll_lua_pushnil
155 #define lua_pushnumber dll_lua_pushnumber
156 #define lua_pushinteger dll_lua_pushinteger
157 #define lua_pushlstring dll_lua_pushlstring
158 #define lua_pushstring dll_lua_pushstring
159 #define lua_pushfstring dll_lua_pushfstring
160 #define lua_pushcclosure dll_lua_pushcclosure
161 #define lua_pushboolean dll_lua_pushboolean
162 #define lua_pushlightuserdata dll_lua_pushlightuserdata
163 #define lua_getfield dll_lua_getfield
164 #define lua_rawget dll_lua_rawget
165 #define lua_rawgeti dll_lua_rawgeti
166 #define lua_createtable dll_lua_createtable
167 #if LUA_VERSION_NUM >= 504
168  #define lua_newuserdatauv dll_lua_newuserdatauv
169 #else
170  #define lua_newuserdata dll_lua_newuserdata
171 #endif
172 #define lua_getmetatable dll_lua_getmetatable
173 #define lua_setfield dll_lua_setfield
174 #define lua_rawset dll_lua_rawset
175 #define lua_rawseti dll_lua_rawseti
176 #define lua_setmetatable dll_lua_setmetatable
177 #define lua_next dll_lua_next
178 /* libs */
179 #define luaopen_base dll_luaopen_base
180 #define luaopen_table dll_luaopen_table
181 #define luaopen_string dll_luaopen_string
182 #define luaopen_math dll_luaopen_math
183 #define luaopen_io dll_luaopen_io
184 #define luaopen_os dll_luaopen_os
185 #define luaopen_package dll_luaopen_package
186 #define luaopen_debug dll_luaopen_debug
187 #define luaL_openlibs dll_luaL_openlibs
188 
189 /* lauxlib */
190 #if LUA_VERSION_NUM <= 501
191 void (*dll_luaL_register) (lua_State *L, const char *libname, const luaL_Reg *l);
192 char *(*dll_luaL_prepbuffer) (luaL_Buffer *B);
193 void (*dll_luaL_openlib) (lua_State *L, const char *libname, const luaL_Reg *l, int nup);
194 int (*dll_luaL_typerror) (lua_State *L, int narg, const char *tname);
195 int (*dll_luaL_loadfile) (lua_State *L, const char *filename);
196 int (*dll_luaL_loadbuffer) (lua_State *L, const char *buff, size_t sz, const char *name);
197 #else
198 char *(*dll_luaL_prepbuffsize) (luaL_Buffer *B, size_t sz);
199 void (*dll_luaL_setfuncs) (lua_State *L, const luaL_Reg *l, int nup);
200 int (*dll_luaL_loadfilex) (lua_State *L, const char *filename, const char *mode);
201 int (*dll_luaL_loadbufferx) (lua_State *L, const char *buff, size_t sz, const char *name, const char *mode);
202 int (*dll_luaL_argerror) (lua_State *L, int numarg, const char *extramsg);
203 #endif
204 void (*dll_luaL_checkany) (lua_State *L, int narg);
205 const char *(*dll_luaL_checklstring) (lua_State *L, int numArg, size_t *l);
206 lua_Integer (*dll_luaL_checkinteger) (lua_State *L, int numArg);
207 lua_Integer (*dll_luaL_optinteger) (lua_State *L, int nArg, lua_Integer def);
208 void (*dll_luaL_checktype) (lua_State *L, int narg, int t);
209 int (*dll_luaL_error) (lua_State *L, const char *fmt, ...);
210 lua_State *(*dll_luaL_newstate) (void);
211 void (*dll_luaL_buffinit) (lua_State *L, luaL_Buffer *B);
212 void (*dll_luaL_addlstring) (luaL_Buffer *B, const char *s, size_t l);
213 void (*dll_luaL_pushresult) (luaL_Buffer *B);
214 /* lua */
215 #if LUA_VERSION_NUM <= 501
216 lua_Number (*dll_lua_tonumber) (lua_State *L, int idx);
217 lua_Integer (*dll_lua_tointeger) (lua_State *L, int idx);
218 void (*dll_lua_call) (lua_State *L, int nargs, int nresults);
219 int (*dll_lua_pcall) (lua_State *L, int nargs, int nresults, int errfunc);
220 #else
221 lua_Number (*dll_lua_tonumberx) (lua_State *L, int idx, int *isnum);
222 lua_Integer (*dll_lua_tointegerx) (lua_State *L, int idx, int *isnum);
223 void (*dll_lua_callk) (lua_State *L, int nargs, int nresults, int ctx,
224 	lua_CFunction k);
225 int (*dll_lua_pcallk) (lua_State *L, int nargs, int nresults, int errfunc,
226 	int ctx, lua_CFunction k);
227 void (*dll_lua_getglobal) (lua_State *L, const char *var);
228 void (*dll_lua_setglobal) (lua_State *L, const char *var);
229 #endif
230 #if LUA_VERSION_NUM <= 502
231 void (*dll_lua_replace) (lua_State *L, int idx);
232 void (*dll_lua_remove) (lua_State *L, int idx);
233 #endif
234 #if LUA_VERSION_NUM >= 503
235 void  (*dll_lua_rotate) (lua_State *L, int idx, int n);
236 void (*dll_lua_copy) (lua_State *L, int fromidx, int toidx);
237 #endif
238 const char *(*dll_lua_typename) (lua_State *L, int tp);
239 void       (*dll_lua_close) (lua_State *L);
240 int (*dll_lua_gettop) (lua_State *L);
241 void (*dll_lua_settop) (lua_State *L, int idx);
242 void (*dll_lua_pushvalue) (lua_State *L, int idx);
243 int (*dll_lua_isnumber) (lua_State *L, int idx);
244 int (*dll_lua_isstring) (lua_State *L, int idx);
245 int (*dll_lua_type) (lua_State *L, int idx);
246 int (*dll_lua_rawequal) (lua_State *L, int idx1, int idx2);
247 int (*dll_lua_toboolean) (lua_State *L, int idx);
248 const char *(*dll_lua_tolstring) (lua_State *L, int idx, size_t *len);
249 void *(*dll_lua_touserdata) (lua_State *L, int idx);
250 void (*dll_lua_pushnil) (lua_State *L);
251 void (*dll_lua_pushnumber) (lua_State *L, lua_Number n);
252 void (*dll_lua_pushinteger) (lua_State *L, lua_Integer n);
253 void (*dll_lua_pushlstring) (lua_State *L, const char *s, size_t l);
254 void (*dll_lua_pushstring) (lua_State *L, const char *s);
255 const char *(*dll_lua_pushfstring) (lua_State *L, const char *fmt, ...);
256 void (*dll_lua_pushcclosure) (lua_State *L, lua_CFunction fn, int n);
257 void (*dll_lua_pushboolean) (lua_State *L, int b);
258 void (*dll_lua_pushlightuserdata) (lua_State *L, void *p);
259 void (*dll_lua_getfield) (lua_State *L, int idx, const char *k);
260 #if LUA_VERSION_NUM <= 502
261 void (*dll_lua_rawget) (lua_State *L, int idx);
262 void (*dll_lua_rawgeti) (lua_State *L, int idx, int n);
263 #else
264 int (*dll_lua_rawget) (lua_State *L, int idx);
265 int (*dll_lua_rawgeti) (lua_State *L, int idx, lua_Integer n);
266 #endif
267 void (*dll_lua_createtable) (lua_State *L, int narr, int nrec);
268 #if LUA_VERSION_NUM >= 504
269 void *(*dll_lua_newuserdatauv) (lua_State *L, size_t sz, int nuvalue);
270 #else
271 void *(*dll_lua_newuserdata) (lua_State *L, size_t sz);
272 #endif
273 int (*dll_lua_getmetatable) (lua_State *L, int objindex);
274 void (*dll_lua_setfield) (lua_State *L, int idx, const char *k);
275 void (*dll_lua_rawset) (lua_State *L, int idx);
276 #if LUA_VERSION_NUM <= 502
277 void (*dll_lua_rawseti) (lua_State *L, int idx, int n);
278 #else
279 void (*dll_lua_rawseti) (lua_State *L, int idx, lua_Integer n);
280 #endif
281 int (*dll_lua_setmetatable) (lua_State *L, int objindex);
282 int (*dll_lua_next) (lua_State *L, int idx);
283 /* libs */
284 int (*dll_luaopen_base) (lua_State *L);
285 int (*dll_luaopen_table) (lua_State *L);
286 int (*dll_luaopen_string) (lua_State *L);
287 int (*dll_luaopen_math) (lua_State *L);
288 int (*dll_luaopen_io) (lua_State *L);
289 int (*dll_luaopen_os) (lua_State *L);
290 int (*dll_luaopen_package) (lua_State *L);
291 int (*dll_luaopen_debug) (lua_State *L);
292 void (*dll_luaL_openlibs) (lua_State *L);
293 
294 typedef void **luaV_function;
295 typedef struct {
296     const char *name;
297     luaV_function func;
298 } luaV_Reg;
299 
300 static const luaV_Reg luaV_dll[] = {
301     /* lauxlib */
302 #if LUA_VERSION_NUM <= 501
303     {"luaL_register", (luaV_function) &dll_luaL_register},
304     {"luaL_prepbuffer", (luaV_function) &dll_luaL_prepbuffer},
305     {"luaL_openlib", (luaV_function) &dll_luaL_openlib},
306     {"luaL_typerror", (luaV_function) &dll_luaL_typerror},
307     {"luaL_loadfile", (luaV_function) &dll_luaL_loadfile},
308     {"luaL_loadbuffer", (luaV_function) &dll_luaL_loadbuffer},
309 #else
310     {"luaL_prepbuffsize", (luaV_function) &dll_luaL_prepbuffsize},
311     {"luaL_setfuncs", (luaV_function) &dll_luaL_setfuncs},
312     {"luaL_loadfilex", (luaV_function) &dll_luaL_loadfilex},
313     {"luaL_loadbufferx", (luaV_function) &dll_luaL_loadbufferx},
314     {"luaL_argerror", (luaV_function) &dll_luaL_argerror},
315 #endif
316     {"luaL_checkany", (luaV_function) &dll_luaL_checkany},
317     {"luaL_checklstring", (luaV_function) &dll_luaL_checklstring},
318     {"luaL_checkinteger", (luaV_function) &dll_luaL_checkinteger},
319     {"luaL_optinteger", (luaV_function) &dll_luaL_optinteger},
320     {"luaL_checktype", (luaV_function) &dll_luaL_checktype},
321     {"luaL_error", (luaV_function) &dll_luaL_error},
322     {"luaL_newstate", (luaV_function) &dll_luaL_newstate},
323     {"luaL_buffinit", (luaV_function) &dll_luaL_buffinit},
324     {"luaL_addlstring", (luaV_function) &dll_luaL_addlstring},
325     {"luaL_pushresult", (luaV_function) &dll_luaL_pushresult},
326     /* lua */
327 #if LUA_VERSION_NUM <= 501
328     {"lua_tonumber", (luaV_function) &dll_lua_tonumber},
329     {"lua_tointeger", (luaV_function) &dll_lua_tointeger},
330     {"lua_call", (luaV_function) &dll_lua_call},
331     {"lua_pcall", (luaV_function) &dll_lua_pcall},
332 #else
333     {"lua_tonumberx", (luaV_function) &dll_lua_tonumberx},
334     {"lua_tointegerx", (luaV_function) &dll_lua_tointegerx},
335     {"lua_callk", (luaV_function) &dll_lua_callk},
336     {"lua_pcallk", (luaV_function) &dll_lua_pcallk},
337     {"lua_getglobal", (luaV_function) &dll_lua_getglobal},
338     {"lua_setglobal", (luaV_function) &dll_lua_setglobal},
339 #endif
340 #if LUA_VERSION_NUM <= 502
341     {"lua_replace", (luaV_function) &dll_lua_replace},
342     {"lua_remove", (luaV_function) &dll_lua_remove},
343 #endif
344 #if LUA_VERSION_NUM >= 503
345     {"lua_rotate", (luaV_function) &dll_lua_rotate},
346     {"lua_copy", (luaV_function) &dll_lua_copy},
347 #endif
348     {"lua_typename", (luaV_function) &dll_lua_typename},
349     {"lua_close", (luaV_function) &dll_lua_close},
350     {"lua_gettop", (luaV_function) &dll_lua_gettop},
351     {"lua_settop", (luaV_function) &dll_lua_settop},
352     {"lua_pushvalue", (luaV_function) &dll_lua_pushvalue},
353     {"lua_isnumber", (luaV_function) &dll_lua_isnumber},
354     {"lua_isstring", (luaV_function) &dll_lua_isstring},
355     {"lua_type", (luaV_function) &dll_lua_type},
356     {"lua_rawequal", (luaV_function) &dll_lua_rawequal},
357     {"lua_toboolean", (luaV_function) &dll_lua_toboolean},
358     {"lua_tolstring", (luaV_function) &dll_lua_tolstring},
359     {"lua_touserdata", (luaV_function) &dll_lua_touserdata},
360     {"lua_pushnil", (luaV_function) &dll_lua_pushnil},
361     {"lua_pushnumber", (luaV_function) &dll_lua_pushnumber},
362     {"lua_pushinteger", (luaV_function) &dll_lua_pushinteger},
363     {"lua_pushlstring", (luaV_function) &dll_lua_pushlstring},
364     {"lua_pushstring", (luaV_function) &dll_lua_pushstring},
365     {"lua_pushfstring", (luaV_function) &dll_lua_pushfstring},
366     {"lua_pushcclosure", (luaV_function) &dll_lua_pushcclosure},
367     {"lua_pushboolean", (luaV_function) &dll_lua_pushboolean},
368     {"lua_pushlightuserdata", (luaV_function) &dll_lua_pushlightuserdata},
369     {"lua_getfield", (luaV_function) &dll_lua_getfield},
370     {"lua_rawget", (luaV_function) &dll_lua_rawget},
371     {"lua_rawgeti", (luaV_function) &dll_lua_rawgeti},
372     {"lua_createtable", (luaV_function) &dll_lua_createtable},
373 #if LUA_VERSION_NUM >= 504
374     {"lua_newuserdatauv", (luaV_function) &dll_lua_newuserdatauv},
375 #else
376     {"lua_newuserdata", (luaV_function) &dll_lua_newuserdata},
377 #endif
378     {"lua_getmetatable", (luaV_function) &dll_lua_getmetatable},
379     {"lua_setfield", (luaV_function) &dll_lua_setfield},
380     {"lua_rawset", (luaV_function) &dll_lua_rawset},
381     {"lua_rawseti", (luaV_function) &dll_lua_rawseti},
382     {"lua_setmetatable", (luaV_function) &dll_lua_setmetatable},
383     {"lua_next", (luaV_function) &dll_lua_next},
384     /* libs */
385     {"luaopen_base", (luaV_function) &dll_luaopen_base},
386     {"luaopen_table", (luaV_function) &dll_luaopen_table},
387     {"luaopen_string", (luaV_function) &dll_luaopen_string},
388     {"luaopen_math", (luaV_function) &dll_luaopen_math},
389     {"luaopen_io", (luaV_function) &dll_luaopen_io},
390     {"luaopen_os", (luaV_function) &dll_luaopen_os},
391     {"luaopen_package", (luaV_function) &dll_luaopen_package},
392     {"luaopen_debug", (luaV_function) &dll_luaopen_debug},
393     {"luaL_openlibs", (luaV_function) &dll_luaL_openlibs},
394     {NULL, NULL}
395 };
396 
397 static HANDLE hinstLua = NULL;
398 
399     static void
400 end_dynamic_lua(void)
401 {
402     if (hinstLua)
403     {
404 	close_dll(hinstLua);
405 	hinstLua = 0;
406     }
407 }
408 
409     static int
410 lua_link_init(char *libname, int verbose)
411 {
412     const luaV_Reg *reg;
413     if (hinstLua) return OK;
414     hinstLua = load_dll(libname);
415     if (!hinstLua)
416     {
417 	if (verbose)
418 	    EMSG2(_(e_loadlib), libname);
419 	return FAIL;
420     }
421     for (reg = luaV_dll; reg->func; reg++)
422     {
423 	if ((*reg->func = symbol_from_dll(hinstLua, reg->name)) == NULL)
424 	{
425 	    close_dll(hinstLua);
426 	    hinstLua = 0;
427 	    if (verbose)
428 		EMSG2(_(e_loadfunc), reg->name);
429 	    return FAIL;
430 	}
431     }
432     return OK;
433 }
434 #endif /* DYNAMIC_LUA */
435 
436 #if defined(DYNAMIC_LUA) || defined(PROTO)
437     int
438 lua_enabled(int verbose)
439 {
440     return lua_link_init((char *)p_luadll, verbose) == OK;
441 }
442 #endif
443 
444 #if LUA_VERSION_NUM > 501
445     static int
446 luaL_typeerror (lua_State *L, int narg, const char *tname)
447 {
448     const char *msg = lua_pushfstring(L, "%s expected, got %s",
449 	    tname, luaL_typename(L, narg));
450     return luaL_argerror(L, narg, msg);
451 }
452 #endif
453 
454 
455 /* =======   Internal   ======= */
456 
457     static void
458 luaV_newmetatable(lua_State *L, const char *tname)
459 {
460     lua_newtable(L);
461     lua_pushlightuserdata(L, (void *) tname);
462     lua_pushvalue(L, -2);
463     lua_rawset(L, LUA_REGISTRYINDEX);
464 }
465 
466     static void *
467 luaV_toudata(lua_State *L, int ud, const char *tname)
468 {
469     void *p = lua_touserdata(L, ud);
470 
471     if (p != NULL) /* value is userdata? */
472     {
473 	if (lua_getmetatable(L, ud)) /* does it have a metatable? */
474 	{
475 	    luaV_getfield(L, tname); /* get metatable */
476 	    if (lua_rawequal(L, -1, -2)) /* MTs match? */
477 	    {
478 		lua_pop(L, 2); /* MTs */
479 		return p;
480 	    }
481 	}
482     }
483     return NULL;
484 }
485 
486     static void *
487 luaV_checkcache(lua_State *L, void *p)
488 {
489     luaV_getudata(L, p);
490     if (lua_isnil(L, -1)) luaL_error(L, "invalid object");
491     lua_pop(L, 1);
492     return p;
493 }
494 
495 #define luaV_unbox(L,luatyp,ud) (*((luatyp *) lua_touserdata((L),(ud))))
496 
497 #define luaV_checkvalid(L,luatyp,ud) \
498     luaV_checkcache((L), (void *) luaV_unbox((L),luatyp,(ud)))
499 
500     static void *
501 luaV_checkudata(lua_State *L, int ud, const char *tname)
502 {
503     void *p = luaV_toudata(L, ud, tname);
504     if (p == NULL) luaL_typeerror(L, ud, tname);
505     return p;
506 }
507 
508     static void
509 luaV_pushtypval(lua_State *L, typval_T *tv)
510 {
511     if (tv == NULL)
512     {
513 	lua_pushnil(L);
514 	return;
515     }
516     switch (tv->v_type)
517     {
518 	case VAR_STRING:
519 	    lua_pushstring(L, tv->vval.v_string == NULL
520 					    ? "" : (char *)tv->vval.v_string);
521 	    break;
522 	case VAR_NUMBER:
523 	    lua_pushinteger(L, (int) tv->vval.v_number);
524 	    break;
525 #ifdef FEAT_FLOAT
526 	case VAR_FLOAT:
527 	    lua_pushnumber(L, (lua_Number) tv->vval.v_float);
528 	    break;
529 #endif
530 	case VAR_LIST:
531 	    luaV_pushlist(L, tv->vval.v_list);
532 	    break;
533 	case VAR_DICT:
534 	    luaV_pushdict(L, tv->vval.v_dict);
535 	    break;
536 	case VAR_SPECIAL:
537 	    if (tv->vval.v_number <= VVAL_TRUE)
538 		lua_pushinteger(L, (int) tv->vval.v_number);
539 	    else
540 		lua_pushnil(L);
541 	    break;
542 	case VAR_FUNC:
543 	    luaV_pushfuncref(L, tv);
544 	    break;
545 	default:
546 	    lua_pushnil(L);
547     }
548 }
549 
550 /*
551  * Converts lua value at 'pos' to typval 'tv'.
552  * Returns OK or FAIL.
553  */
554     static int
555 luaV_totypval(lua_State *L, int pos, typval_T *tv)
556 {
557     int status = OK;
558 
559     switch (lua_type(L, pos))
560     {
561 	case LUA_TBOOLEAN:
562 	    tv->v_type = VAR_SPECIAL;
563 	    tv->vval.v_number = (varnumber_T) lua_toboolean(L, pos);
564 	    break;
565 	case LUA_TSTRING:
566 	    tv->v_type = VAR_STRING;
567 	    tv->vval.v_string = vim_strsave((char_u *) lua_tostring(L, pos));
568 	    break;
569 	case LUA_TNUMBER:
570 #ifdef FEAT_FLOAT
571 	    tv->v_type = VAR_FLOAT;
572 	    tv->vval.v_float = (float_T) lua_tonumber(L, pos);
573 #else
574 	    tv->v_type = VAR_NUMBER;
575 	    tv->vval.v_number = (varnumber_T) lua_tointeger(L, pos);
576 #endif
577 	    break;
578 	case LUA_TUSERDATA:
579 	{
580 	    void *p = lua_touserdata(L, pos);
581 
582 	    if (lua_getmetatable(L, pos)) /* has metatable? */
583 	    {
584 		/* check list */
585 		luaV_getfield(L, LUAVIM_LIST);
586 		if (lua_rawequal(L, -1, -2))
587 		{
588 		    tv->v_type = VAR_LIST;
589 		    tv->vval.v_list = *((luaV_List *) p);
590 		    ++tv->vval.v_list->lv_refcount;
591 		    lua_pop(L, 2); /* MTs */
592 		    break;
593 		}
594 		/* check dict */
595 		luaV_getfield(L, LUAVIM_DICT);
596 		if (lua_rawequal(L, -1, -3))
597 		{
598 		    tv->v_type = VAR_DICT;
599 		    tv->vval.v_dict = *((luaV_Dict *) p);
600 		    ++tv->vval.v_dict->dv_refcount;
601 		    lua_pop(L, 3); /* MTs */
602 		    break;
603 		}
604 		/* check funcref */
605 		luaV_getfield(L, LUAVIM_FUNCREF);
606 		if (lua_rawequal(L, -1, -4))
607 		{
608 		    luaV_Funcref *f = (luaV_Funcref *) p;
609 		    copy_tv(&f->tv, tv);
610 		    lua_pop(L, 4); /* MTs */
611 		    break;
612 		}
613 		lua_pop(L, 4); /* MTs */
614 	    }
615 	}
616 	/* FALLTHROUGH */
617 	default:
618 	    tv->v_type = VAR_NUMBER;
619 	    tv->vval.v_number = 0;
620 	    status = FAIL;
621     }
622     return status;
623 }
624 
625 /* similar to luaL_addlstring, but replaces \0 with \n if toline and
626  * \n with \0 otherwise */
627     static void
628 luaV_addlstring(luaL_Buffer *b, const char *s, size_t l, int toline)
629 {
630     while (l--)
631     {
632 	if (*s == '\0' && toline)
633 	    luaL_addchar(b, '\n');
634 	else if (*s == '\n' && !toline)
635 	    luaL_addchar(b, '\0');
636 	else
637 	    luaL_addchar(b, *s);
638 	s++;
639     }
640 }
641 
642     static void
643 luaV_pushline(lua_State *L, buf_T *buf, linenr_T n)
644 {
645     const char *s = (const char *) ml_get_buf(buf, n, FALSE);
646     luaL_Buffer b;
647     luaL_buffinit(L, &b);
648     luaV_addlstring(&b, s, strlen(s), 0);
649     luaL_pushresult(&b);
650 }
651 
652     static char_u *
653 luaV_toline(lua_State *L, int pos)
654 {
655     size_t l;
656     const char *s = lua_tolstring(L, pos, &l);
657 
658     luaL_Buffer b;
659     luaL_buffinit(L, &b);
660     luaV_addlstring(&b, s, l, 1);
661     luaL_pushresult(&b);
662     return (char_u *) lua_tostring(L, -1);
663 }
664 
665 /* pops a string s from the top of the stack and calls mf(t) for pieces t of
666  * s separated by newlines */
667     static void
668 luaV_msgfunc(lua_State *L, msgfunc_T mf)
669 {
670     luaL_Buffer b;
671     size_t l;
672     const char *p, *s = lua_tolstring(L, -1, &l);
673     luaL_buffinit(L, &b);
674     luaV_addlstring(&b, s, l, 0);
675     luaL_pushresult(&b);
676     /* break string */
677     p = s = lua_tolstring(L, -1, &l);
678     while (l--)
679     {
680 	if (*p++ == '\0') /* break? */
681 	{
682 	    mf((char_u *) s);
683 	    s = p;
684 	}
685     }
686     mf((char_u *) s);
687     lua_pop(L, 2); /* original and modified strings */
688 }
689 
690 #define luaV_newtype(typ,tname,luatyp,luatname) \
691 	static luatyp * \
692     luaV_new##tname (lua_State *L, typ *obj) \
693     { \
694 	luatyp *o = (luatyp *) lua_newuserdata(L, sizeof(luatyp)); \
695 	*o = obj; \
696 	luaV_setudata(L, obj); /* cache[obj] = udata */ \
697 	luaV_getfield(L, luatname); \
698 	lua_setmetatable(L, -2); \
699 	return o; \
700     }
701 
702 #define luaV_pushtype(typ,tname,luatyp) \
703 	static luatyp * \
704     luaV_push##tname(lua_State *L, typ *obj) \
705     { \
706 	luatyp *o = NULL; \
707 	if (obj == NULL) \
708 	    lua_pushnil(L); \
709 	else { \
710 	    luaV_getudata(L, obj); \
711 	    if (lua_isnil(L, -1)) /* not interned? */ \
712 	    { \
713 		lua_pop(L, 1); \
714 		o = luaV_new##tname(L, obj); \
715 	    } \
716 	    else \
717 		o = (luatyp *) lua_touserdata(L, -1); \
718 	} \
719 	return o; \
720     }
721 
722 #define luaV_type_tostring(tname,luatname) \
723 	static int \
724     luaV_##tname##_tostring (lua_State *L) \
725     { \
726 	lua_pushfstring(L, "%s: %p", luatname, lua_touserdata(L, 1)); \
727 	return 1; \
728     }
729 
730 /* =======   List type   ======= */
731 
732     static luaV_List *
733 luaV_newlist (lua_State *L, list_T *lis)
734 {
735     luaV_List *l = (luaV_List *) lua_newuserdata(L, sizeof(luaV_List));
736     *l = lis;
737     lis->lv_refcount++; /* reference in Lua */
738     luaV_setudata(L, lis); /* cache[lis] = udata */
739     luaV_getfield(L, LUAVIM_LIST);
740     lua_setmetatable(L, -2);
741     return l;
742 }
743 
744 luaV_pushtype(list_T, list, luaV_List)
745 luaV_type_tostring(list, LUAVIM_LIST)
746 
747     static int
748 luaV_list_len (lua_State *L)
749 {
750     list_T *l = luaV_unbox(L, luaV_List, 1);
751     lua_pushinteger(L, (l == NULL) ? 0 : (int) l->lv_len);
752     return 1;
753 }
754 
755     static int
756 luaV_list_iter (lua_State *L)
757 {
758     listitem_T *li = (listitem_T *) lua_touserdata(L, lua_upvalueindex(2));
759     if (li == NULL) return 0;
760     luaV_pushtypval(L, &li->li_tv);
761     lua_pushlightuserdata(L, (void *) li->li_next);
762     lua_replace(L, lua_upvalueindex(2));
763     return 1;
764 }
765 
766     static int
767 luaV_list_call (lua_State *L)
768 {
769     list_T *l = luaV_unbox(L, luaV_List, 1);
770     lua_pushvalue(L, lua_upvalueindex(1)); /* pass cache table along */
771     lua_pushlightuserdata(L, (void *) l->lv_first);
772     lua_pushcclosure(L, luaV_list_iter, 2);
773     return 1;
774 }
775 
776     static int
777 luaV_list_index (lua_State *L)
778 {
779     list_T *l = luaV_unbox(L, luaV_List, 1);
780     if (lua_isnumber(L, 2)) /* list item? */
781     {
782 	listitem_T *li = list_find(l, (long) luaL_checkinteger(L, 2));
783 	if (li == NULL)
784 	    lua_pushnil(L);
785 	else
786 	    luaV_pushtypval(L, &li->li_tv);
787     }
788     else if (lua_isstring(L, 2)) /* method? */
789     {
790 	const char *s = lua_tostring(L, 2);
791 	if (strncmp(s, "add", 3) == 0
792 		|| strncmp(s, "insert", 6) == 0)
793 	{
794 	    lua_getmetatable(L, 1);
795 	    lua_getfield(L, -1, s);
796 	}
797 	else
798 	    lua_pushnil(L);
799     }
800     else
801 	lua_pushnil(L);
802     return 1;
803 }
804 
805     static int
806 luaV_list_newindex (lua_State *L)
807 {
808     list_T *l = luaV_unbox(L, luaV_List, 1);
809     long n = (long) luaL_checkinteger(L, 2);
810     listitem_T *li;
811     if (l->lv_lock)
812 	luaL_error(L, "list is locked");
813     li = list_find(l, n);
814     if (li == NULL) return 0;
815     if (lua_isnil(L, 3)) /* remove? */
816     {
817 	vimlist_remove(l, li, li);
818 	clear_tv(&li->li_tv);
819 	vim_free(li);
820     }
821     else
822     {
823 	typval_T v;
824 	luaV_checktypval(L, 3, &v, "setting list item");
825 	clear_tv(&li->li_tv);
826 	copy_tv(&v, &li->li_tv);
827 	clear_tv(&v);
828     }
829     return 0;
830 }
831 
832     static int
833 luaV_list_add (lua_State *L)
834 {
835     luaV_List *lis = luaV_checkudata(L, 1, LUAVIM_LIST);
836     list_T *l = (list_T *) luaV_checkcache(L, (void *) *lis);
837     typval_T v;
838     if (l->lv_lock)
839 	luaL_error(L, "list is locked");
840     lua_settop(L, 2);
841     luaV_checktypval(L, 2, &v, "adding list item");
842     if (list_append_tv(l, &v) == FAIL)
843     {
844 	clear_tv(&v);
845 	luaL_error(L, "failed to add item to list");
846     }
847     clear_tv(&v);
848     lua_settop(L, 1);
849     return 1;
850 }
851 
852     static int
853 luaV_list_insert (lua_State *L)
854 {
855     luaV_List *lis = luaV_checkudata(L, 1, LUAVIM_LIST);
856     list_T *l = (list_T *) luaV_checkcache(L, (void *) *lis);
857     long pos = (long) luaL_optinteger(L, 3, 0);
858     listitem_T *li = NULL;
859     typval_T v;
860     if (l->lv_lock)
861 	luaL_error(L, "list is locked");
862     if (pos < l->lv_len)
863     {
864 	li = list_find(l, pos);
865 	if (li == NULL)
866 	    luaL_error(L, "invalid position");
867     }
868     lua_settop(L, 2);
869     luaV_checktypval(L, 2, &v, "inserting list item");
870     if (list_insert_tv(l, &v, li) == FAIL)
871     {
872 	clear_tv(&v);
873 	luaL_error(L, "failed to add item to list");
874     }
875     clear_tv(&v);
876     lua_settop(L, 1);
877     return 1;
878 }
879 
880 static const luaL_Reg luaV_List_mt[] = {
881     {"__tostring", luaV_list_tostring},
882     {"__len", luaV_list_len},
883     {"__call", luaV_list_call},
884     {"__index", luaV_list_index},
885     {"__newindex", luaV_list_newindex},
886     {"add", luaV_list_add},
887     {"insert", luaV_list_insert},
888     {NULL, NULL}
889 };
890 
891 
892 /* =======   Dict type   ======= */
893 
894     static luaV_Dict *
895 luaV_newdict (lua_State *L, dict_T *dic)
896 {
897     luaV_Dict *d = (luaV_Dict *) lua_newuserdata(L, sizeof(luaV_Dict));
898     *d = dic;
899     dic->dv_refcount++; /* reference in Lua */
900     luaV_setudata(L, dic); /* cache[dic] = udata */
901     luaV_getfield(L, LUAVIM_DICT);
902     lua_setmetatable(L, -2);
903     return d;
904 }
905 
906 luaV_pushtype(dict_T, dict, luaV_Dict)
907 luaV_type_tostring(dict, LUAVIM_DICT)
908 
909     static int
910 luaV_dict_len (lua_State *L)
911 {
912     dict_T *d = luaV_unbox(L, luaV_Dict, 1);
913     lua_pushinteger(L, (d == NULL) ? 0 : (int) d->dv_hashtab.ht_used);
914     return 1;
915 }
916 
917     static int
918 luaV_dict_iter (lua_State *L UNUSED)
919 {
920 #ifdef FEAT_EVAL
921     hashitem_T *hi = (hashitem_T *) lua_touserdata(L, lua_upvalueindex(2));
922     int n = lua_tointeger(L, lua_upvalueindex(3));
923     dictitem_T *di;
924     if (n <= 0) return 0;
925     while (HASHITEM_EMPTY(hi)) hi++;
926     di = dict_lookup(hi);
927     lua_pushstring(L, (char *) hi->hi_key);
928     luaV_pushtypval(L, &di->di_tv);
929     lua_pushlightuserdata(L, (void *) (hi + 1));
930     lua_replace(L, lua_upvalueindex(2));
931     lua_pushinteger(L, n - 1);
932     lua_replace(L, lua_upvalueindex(3));
933     return 2;
934 #else
935     return 0;
936 #endif
937 }
938 
939     static int
940 luaV_dict_call (lua_State *L)
941 {
942     dict_T *d = luaV_unbox(L, luaV_Dict, 1);
943     hashtab_T *ht = &d->dv_hashtab;
944     lua_pushvalue(L, lua_upvalueindex(1)); /* pass cache table along */
945     lua_pushlightuserdata(L, (void *) ht->ht_array);
946     lua_pushinteger(L, ht->ht_used); /* # remaining items */
947     lua_pushcclosure(L, luaV_dict_iter, 3);
948     return 1;
949 }
950 
951     static int
952 luaV_dict_index(lua_State *L)
953 {
954     dict_T *d = luaV_unbox(L, luaV_Dict, 1);
955     char_u *key = (char_u *) luaL_checkstring(L, 2);
956     dictitem_T *di = dict_find(d, key, -1);
957 
958     if (di == NULL)
959 	lua_pushnil(L);
960     else
961     {
962 	luaV_pushtypval(L, &di->di_tv);
963 	if (di->di_tv.v_type == VAR_FUNC) /* funcref? */
964 	{
965 	    luaV_Funcref *f = (luaV_Funcref *) lua_touserdata(L, -1);
966 	    f->self = d; /* keep "self" reference */
967 	    d->dv_refcount++;
968 	}
969     }
970     return 1;
971 }
972 
973     static int
974 luaV_dict_newindex(lua_State *L)
975 {
976     dict_T *d = luaV_unbox(L, luaV_Dict, 1);
977     char_u *key = (char_u *) luaL_checkstring(L, 2);
978     dictitem_T *di;
979     typval_T v;
980     if (d->dv_lock)
981 	luaL_error(L, "dict is locked");
982     if (key == NULL)
983 	return 0;
984     if (*key == NUL)
985 	luaL_error(L, "empty key");
986     if (!lua_isnil(L, 3)) /* read value? */
987     {
988 	luaV_checktypval(L, 3, &v, "setting dict item");
989 	if (d->dv_scope == VAR_DEF_SCOPE && v.v_type == VAR_FUNC)
990 	    luaL_error(L, "cannot assign funcref to builtin scope");
991     }
992     di = dict_find(d, key, -1);
993     if (di == NULL) /* non-existing key? */
994     {
995 	if (lua_isnil(L, 3))
996 	    return 0;
997 	di = dictitem_alloc(key);
998 	if (di == NULL)
999 	    return 0;
1000 	if (dict_add(d, di) == FAIL)
1001 	{
1002 	    vim_free(di);
1003 	    return 0;
1004 	}
1005     }
1006     else
1007 	clear_tv(&di->di_tv);
1008     if (lua_isnil(L, 3)) /* remove? */
1009     {
1010 	hashitem_T *hi = hash_find(&d->dv_hashtab, di->di_key);
1011 	hash_remove(&d->dv_hashtab, hi);
1012 	dictitem_free(di);
1013     }
1014     else
1015     {
1016 	copy_tv(&v, &di->di_tv);
1017 	clear_tv(&v);
1018     }
1019     return 0;
1020 }
1021 
1022 static const luaL_Reg luaV_Dict_mt[] = {
1023     {"__tostring", luaV_dict_tostring},
1024     {"__len", luaV_dict_len},
1025     {"__call", luaV_dict_call},
1026     {"__index", luaV_dict_index},
1027     {"__newindex", luaV_dict_newindex},
1028     {NULL, NULL}
1029 };
1030 
1031 
1032 /* =======   Funcref type   ======= */
1033 
1034     static luaV_Funcref *
1035 luaV_newfuncref(lua_State *L, char_u *name)
1036 {
1037     luaV_Funcref *f = (luaV_Funcref *)lua_newuserdata(L, sizeof(luaV_Funcref));
1038 
1039     if (name != NULL)
1040     {
1041 	func_ref(name); /* as in copy_tv */
1042 	f->tv.vval.v_string = vim_strsave(name);
1043     }
1044     f->tv.v_type = VAR_FUNC;
1045     f->args.v_type = VAR_LIST;
1046     f->self = NULL;
1047     luaV_getfield(L, LUAVIM_FUNCREF);
1048     lua_setmetatable(L, -2);
1049     return f;
1050 }
1051 
1052     static luaV_Funcref *
1053 luaV_pushfuncref(lua_State *L, typval_T *tv)
1054 {
1055     luaV_Funcref *f = luaV_newfuncref(L, NULL);
1056     copy_tv(tv, &f->tv);
1057     clear_tv(tv);
1058     return f;
1059 }
1060 
1061 
1062 luaV_type_tostring(funcref, LUAVIM_FUNCREF)
1063 
1064     static int
1065 luaV_funcref_gc(lua_State *L)
1066 {
1067     luaV_Funcref *f = (luaV_Funcref *) lua_touserdata(L, 1);
1068 
1069     func_unref(f->tv.vval.v_string);
1070     vim_free(f->tv.vval.v_string);
1071     dict_unref(f->self);
1072     return 0;
1073 }
1074 
1075 /* equivalent to string(funcref) */
1076     static int
1077 luaV_funcref_len(lua_State *L)
1078 {
1079     luaV_Funcref *f = (luaV_Funcref *) lua_touserdata(L, 1);
1080 
1081     lua_pushstring(L, (const char *) f->tv.vval.v_string);
1082     return 1;
1083 }
1084 
1085     static int
1086 luaV_funcref_call(lua_State *L)
1087 {
1088     luaV_Funcref *f = (luaV_Funcref *) lua_touserdata(L, 1);
1089     int i, n = lua_gettop(L) - 1; /* #args */
1090     int status;
1091     typval_T v, rettv;
1092 
1093     f->args.vval.v_list = list_alloc();
1094     rettv.v_type = VAR_UNKNOWN; /* as in clear_tv */
1095     if (f->args.vval.v_list == NULL)
1096 	status = FAIL;
1097     else
1098     {
1099 	for (i = 0; i < n; i++)
1100 	{
1101 	    luaV_checktypval(L, i + 2, &v, "calling funcref");
1102 	    list_append_tv(f->args.vval.v_list, &v);
1103 	}
1104 	status = func_call(f->tv.vval.v_string, &f->args,
1105 							NULL, f->self, &rettv);
1106 	if (status == OK)
1107 	    luaV_pushtypval(L, &rettv);
1108 	clear_tv(&f->args);
1109 	clear_tv(&rettv);
1110     }
1111     if (status != OK)
1112 	luaL_error(L, "cannot call funcref");
1113     return 1;
1114 }
1115 
1116 static const luaL_Reg luaV_Funcref_mt[] = {
1117     {"__tostring", luaV_funcref_tostring},
1118     {"__gc", luaV_funcref_gc},
1119     {"__len", luaV_funcref_len},
1120     {"__call", luaV_funcref_call},
1121     {NULL, NULL}
1122 };
1123 
1124 
1125 /* =======   Buffer type   ======= */
1126 
1127 luaV_newtype(buf_T, buffer, luaV_Buffer, LUAVIM_BUFFER)
1128 luaV_pushtype(buf_T, buffer, luaV_Buffer)
1129 luaV_type_tostring(buffer, LUAVIM_BUFFER)
1130 
1131     static int
1132 luaV_buffer_len(lua_State *L)
1133 {
1134     buf_T *b = (buf_T *) luaV_checkvalid(L, luaV_Buffer, 1);
1135     lua_pushinteger(L, b->b_ml.ml_line_count);
1136     return 1;
1137 }
1138 
1139     static int
1140 luaV_buffer_call(lua_State *L)
1141 {
1142     buf_T *b = (buf_T *) luaV_checkvalid(L, luaV_Buffer, 1);
1143     lua_settop(L, 1);
1144     set_curbuf(b, DOBUF_SPLIT);
1145     return 1;
1146 }
1147 
1148     static int
1149 luaV_buffer_index(lua_State *L)
1150 {
1151     buf_T *b = (buf_T *) luaV_checkvalid(L, luaV_Buffer, 1);
1152     linenr_T n = (linenr_T) lua_tointeger(L, 2);
1153     if (n > 0 && n <= b->b_ml.ml_line_count)
1154 	luaV_pushline(L, b, n);
1155     else if (lua_isstring(L, 2))
1156     {
1157 	const char *s = lua_tostring(L, 2);
1158 	if (strncmp(s, "name", 4) == 0)
1159 	    lua_pushstring(L, (b->b_sfname == NULL)
1160 					? "" : (char *) b->b_sfname);
1161 	else if (strncmp(s, "fname", 5) == 0)
1162 	    lua_pushstring(L, (b->b_ffname == NULL)
1163 					? "" : (char *) b->b_ffname);
1164 	else if (strncmp(s, "number", 6) == 0)
1165 	    lua_pushinteger(L, b->b_fnum);
1166 	/* methods */
1167 	else if (strncmp(s,   "insert", 6) == 0
1168 		|| strncmp(s, "next", 4) == 0
1169 		|| strncmp(s, "previous", 8) == 0
1170 		|| strncmp(s, "isvalid", 7) == 0)
1171 	{
1172 	    lua_getmetatable(L, 1);
1173 	    lua_getfield(L, -1, s);
1174 	}
1175 	else
1176 	    lua_pushnil(L);
1177     }
1178     else
1179 	lua_pushnil(L);
1180     return 1;
1181 }
1182 
1183     static int
1184 luaV_buffer_newindex(lua_State *L)
1185 {
1186     buf_T *b = (buf_T *) luaV_checkvalid(L, luaV_Buffer, 1);
1187     linenr_T n = (linenr_T) luaL_checkinteger(L, 2);
1188 #ifdef HAVE_SANDBOX
1189     luaV_checksandbox(L);
1190 #endif
1191     if (n < 1 || n > b->b_ml.ml_line_count)
1192 	luaL_error(L, "invalid line number");
1193     if (lua_isnil(L, 3)) /* delete line */
1194     {
1195 	buf_T *buf = curbuf;
1196 	curbuf = b;
1197 	if (u_savedel(n, 1L) == FAIL)
1198 	{
1199 	    curbuf = buf;
1200 	    luaL_error(L, "cannot save undo information");
1201 	}
1202 	else if (ml_delete(n, FALSE) == FAIL)
1203 	{
1204 	    curbuf = buf;
1205 	    luaL_error(L, "cannot delete line");
1206 	}
1207 	else
1208 	{
1209 	    deleted_lines_mark(n, 1L);
1210 	    if (b == curwin->w_buffer) /* fix cursor in current window? */
1211 	    {
1212 		if (curwin->w_cursor.lnum >= n)
1213 		{
1214 		    if (curwin->w_cursor.lnum > n)
1215 		    {
1216 			curwin->w_cursor.lnum -= 1;
1217 			check_cursor_col();
1218 		    }
1219 		    else check_cursor();
1220 		    changed_cline_bef_curs();
1221 		}
1222 		invalidate_botline();
1223 	    }
1224 	}
1225 	curbuf = buf;
1226     }
1227     else if (lua_isstring(L, 3)) /* update line */
1228     {
1229 	buf_T *buf = curbuf;
1230 	curbuf = b;
1231 	if (u_savesub(n) == FAIL)
1232 	{
1233 	    curbuf = buf;
1234 	    luaL_error(L, "cannot save undo information");
1235 	}
1236 	else if (ml_replace(n, luaV_toline(L, 3), TRUE) == FAIL)
1237 	{
1238 	    curbuf = buf;
1239 	    luaL_error(L, "cannot replace line");
1240 	}
1241 	else changed_bytes(n, 0);
1242 	curbuf = buf;
1243 	if (b == curwin->w_buffer)
1244 	    check_cursor_col();
1245     }
1246     else
1247 	luaL_error(L, "wrong argument to change line");
1248     return 0;
1249 }
1250 
1251     static int
1252 luaV_buffer_insert(lua_State *L)
1253 {
1254     luaV_Buffer *lb = luaV_checkudata(L, 1, LUAVIM_BUFFER);
1255     buf_T *b = (buf_T *) luaV_checkcache(L, (void *) *lb);
1256     linenr_T last = b->b_ml.ml_line_count;
1257     linenr_T n = (linenr_T) luaL_optinteger(L, 3, last);
1258     buf_T *buf;
1259     luaL_checktype(L, 2, LUA_TSTRING);
1260 #ifdef HAVE_SANDBOX
1261     luaV_checksandbox(L);
1262 #endif
1263     /* fix insertion line */
1264     if (n < 0) n = 0;
1265     if (n > last) n = last;
1266     /* insert */
1267     buf = curbuf;
1268     curbuf = b;
1269     if (u_save(n, n + 1) == FAIL)
1270     {
1271 	curbuf = buf;
1272 	luaL_error(L, "cannot save undo information");
1273     }
1274     else if (ml_append(n, luaV_toline(L, 2), 0, FALSE) == FAIL)
1275     {
1276 	curbuf = buf;
1277 	luaL_error(L, "cannot insert line");
1278     }
1279     else
1280 	appended_lines_mark(n, 1L);
1281     curbuf = buf;
1282     update_screen(VALID);
1283     return 0;
1284 }
1285 
1286     static int
1287 luaV_buffer_next(lua_State *L)
1288 {
1289     luaV_Buffer *b = luaV_checkudata(L, 1, LUAVIM_BUFFER);
1290     buf_T *buf = (buf_T *) luaV_checkcache(L, (void *) *b);
1291     luaV_pushbuffer(L, buf->b_next);
1292     return 1;
1293 }
1294 
1295     static int
1296 luaV_buffer_previous(lua_State *L)
1297 {
1298     luaV_Buffer *b = luaV_checkudata(L, 1, LUAVIM_BUFFER);
1299     buf_T *buf = (buf_T *) luaV_checkcache(L, (void *) *b);
1300     luaV_pushbuffer(L, buf->b_prev);
1301     return 1;
1302 }
1303 
1304     static int
1305 luaV_buffer_isvalid(lua_State *L)
1306 {
1307     luaV_Buffer *b = luaV_checkudata(L, 1, LUAVIM_BUFFER);
1308     luaV_getudata(L, *b);
1309     lua_pushboolean(L, !lua_isnil(L, -1));
1310     return 1;
1311 }
1312 
1313 static const luaL_Reg luaV_Buffer_mt[] = {
1314     {"__tostring", luaV_buffer_tostring},
1315     {"__len", luaV_buffer_len},
1316     {"__call", luaV_buffer_call},
1317     {"__index", luaV_buffer_index},
1318     {"__newindex", luaV_buffer_newindex},
1319     {"insert", luaV_buffer_insert},
1320     {"next", luaV_buffer_next},
1321     {"previous", luaV_buffer_previous},
1322     {"isvalid", luaV_buffer_isvalid},
1323     {NULL, NULL}
1324 };
1325 
1326 
1327 /* =======   Window type   ======= */
1328 
1329 luaV_newtype(win_T, window, luaV_Window, LUAVIM_WINDOW)
1330 luaV_pushtype(win_T, window, luaV_Window)
1331 luaV_type_tostring(window, LUAVIM_WINDOW)
1332 
1333     static int
1334 luaV_window_call(lua_State *L)
1335 {
1336     win_T *w = (win_T *) luaV_checkvalid(L, luaV_Window, 1);
1337     lua_settop(L, 1);
1338     win_goto(w);
1339     return 1;
1340 }
1341 
1342     static int
1343 luaV_window_index(lua_State *L)
1344 {
1345     win_T *w = (win_T *) luaV_checkvalid(L, luaV_Window, 1);
1346     const char *s = luaL_checkstring(L, 2);
1347     if (strncmp(s, "buffer", 6) == 0)
1348 	luaV_pushbuffer(L, w->w_buffer);
1349     else if (strncmp(s, "line", 4) == 0)
1350 	lua_pushinteger(L, w->w_cursor.lnum);
1351     else if (strncmp(s, "col", 3) == 0)
1352 	lua_pushinteger(L, w->w_cursor.col + 1);
1353     else if (strncmp(s, "width", 5) == 0)
1354 	lua_pushinteger(L, w->w_width);
1355     else if (strncmp(s, "height", 6) == 0)
1356 	lua_pushinteger(L, w->w_height);
1357     /* methods */
1358     else if (strncmp(s,   "next", 4) == 0
1359 	    || strncmp(s, "previous", 8) == 0
1360 	    || strncmp(s, "isvalid", 7) == 0)
1361     {
1362 	lua_getmetatable(L, 1);
1363 	lua_getfield(L, -1, s);
1364     }
1365     else
1366 	lua_pushnil(L);
1367     return 1;
1368 }
1369 
1370     static int
1371 luaV_window_newindex (lua_State *L)
1372 {
1373     win_T *w = (win_T *) luaV_checkvalid(L, luaV_Window, 1);
1374     const char *s = luaL_checkstring(L, 2);
1375     int v = luaL_checkinteger(L, 3);
1376     if (strncmp(s, "line", 4) == 0)
1377     {
1378 #ifdef HAVE_SANDBOX
1379 	luaV_checksandbox(L);
1380 #endif
1381 	if (v < 1 || v > w->w_buffer->b_ml.ml_line_count)
1382 	    luaL_error(L, "line out of range");
1383 	w->w_cursor.lnum = v;
1384 	update_screen(VALID);
1385     }
1386     else if (strncmp(s, "col", 3) == 0)
1387     {
1388 #ifdef HAVE_SANDBOX
1389 	luaV_checksandbox(L);
1390 #endif
1391 	w->w_cursor.col = v - 1;
1392 	w->w_set_curswant = TRUE;
1393 	update_screen(VALID);
1394     }
1395     else if (strncmp(s, "width", 5) == 0)
1396     {
1397 	win_T *win = curwin;
1398 #ifdef FEAT_GUI
1399 	need_mouse_correct = TRUE;
1400 #endif
1401 	curwin = w;
1402 	win_setwidth(v);
1403 	curwin = win;
1404     }
1405     else if (strncmp(s, "height", 6) == 0)
1406     {
1407 	win_T *win = curwin;
1408 #ifdef FEAT_GUI
1409 	need_mouse_correct = TRUE;
1410 #endif
1411 	curwin = w;
1412 	win_setheight(v);
1413 	curwin = win;
1414     }
1415     else
1416 	luaL_error(L, "invalid window property: `%s'", s);
1417     return 0;
1418 }
1419 
1420     static int
1421 luaV_window_next(lua_State *L)
1422 {
1423     luaV_Window *w = luaV_checkudata(L, 1, LUAVIM_WINDOW);
1424     win_T *win = (win_T *) luaV_checkcache(L, (void *) *w);
1425     luaV_pushwindow(L, win->w_next);
1426     return 1;
1427 }
1428 
1429     static int
1430 luaV_window_previous(lua_State *L)
1431 {
1432     luaV_Window *w = luaV_checkudata(L, 1, LUAVIM_WINDOW);
1433     win_T *win = (win_T *) luaV_checkcache(L, (void *) *w);
1434     luaV_pushwindow(L, win->w_prev);
1435     return 1;
1436 }
1437 
1438     static int
1439 luaV_window_isvalid(lua_State *L)
1440 {
1441     luaV_Window *w = luaV_checkudata(L, 1, LUAVIM_WINDOW);
1442     luaV_getudata(L, *w);
1443     lua_pushboolean(L, !lua_isnil(L, -1));
1444     return 1;
1445 }
1446 
1447 static const luaL_Reg luaV_Window_mt[] = {
1448     {"__tostring", luaV_window_tostring},
1449     {"__call", luaV_window_call},
1450     {"__index", luaV_window_index},
1451     {"__newindex", luaV_window_newindex},
1452     {"next", luaV_window_next},
1453     {"previous", luaV_window_previous},
1454     {"isvalid", luaV_window_isvalid},
1455     {NULL, NULL}
1456 };
1457 
1458 
1459 /* =======   Vim module   ======= */
1460 
1461     static int
1462 luaV_print(lua_State *L)
1463 {
1464     int i, n = lua_gettop(L); /* nargs */
1465     const char *s;
1466     size_t l;
1467     luaL_Buffer b;
1468     luaL_buffinit(L, &b);
1469     lua_getglobal(L, "tostring");
1470     for (i = 1; i <= n; i++)
1471     {
1472 	lua_pushvalue(L, -1); /* tostring */
1473 	lua_pushvalue(L, i); /* arg */
1474 	lua_call(L, 1, 1);
1475 	s = lua_tolstring(L, -1, &l);
1476 	if (s == NULL)
1477 	    return luaL_error(L, "cannot convert to string");
1478 	if (i > 1) luaL_addchar(&b, ' '); /* use space instead of tab */
1479 	luaV_addlstring(&b, s, l, 0);
1480 	lua_pop(L, 1);
1481     }
1482     luaL_pushresult(&b);
1483     luaV_msg(L);
1484     return 0;
1485 }
1486 
1487     static int
1488 luaV_debug(lua_State *L)
1489 {
1490     lua_settop(L, 0);
1491     lua_getglobal(L, "vim");
1492     lua_getfield(L, -1, "eval");
1493     lua_remove(L, -2); /* vim.eval at position 1 */
1494     for (;;)
1495     {
1496 	const char *input;
1497 	size_t l;
1498 	lua_pushvalue(L, 1); /* vim.eval */
1499 	lua_pushliteral(L, "input('lua_debug> ')");
1500 	lua_call(L, 1, 1); /* return string */
1501 	input = lua_tolstring(L, -1, &l);
1502 	if (l == 0 || strcmp(input, "cont") == 0)
1503 	    return 0;
1504 	msg_putchar('\n'); /* avoid outputting on input line */
1505 	if (luaL_loadbuffer(L, input, l, "=(debug command)")
1506 		|| lua_pcall(L, 0, 0, 0))
1507 	    luaV_emsg(L);
1508 	lua_settop(L, 1); /* remove eventual returns, but keep vim.eval */
1509     }
1510 }
1511 
1512     static int
1513 luaV_command(lua_State *L)
1514 {
1515     do_cmdline_cmd((char_u *) luaL_checkstring(L, 1));
1516     update_screen(VALID);
1517     return 0;
1518 }
1519 
1520     static int
1521 luaV_eval(lua_State *L)
1522 {
1523     typval_T *tv = eval_expr((char_u *) luaL_checkstring(L, 1), NULL);
1524     if (tv == NULL) luaL_error(L, "invalid expression");
1525     luaV_pushtypval(L, tv);
1526     free_tv(tv);
1527     return 1;
1528 }
1529 
1530     static int
1531 luaV_beep(lua_State *L UNUSED)
1532 {
1533     vim_beep(BO_LANG);
1534     return 0;
1535 }
1536 
1537     static int
1538 luaV_line(lua_State *L)
1539 {
1540     luaV_pushline(L, curbuf, curwin->w_cursor.lnum);
1541     return 1;
1542 }
1543 
1544     static int
1545 luaV_list(lua_State *L)
1546 {
1547     list_T *l;
1548     int initarg = !lua_isnoneornil(L, 1);
1549 
1550     if (initarg && lua_type(L, 1) != LUA_TTABLE)
1551 	luaL_error(L, "table expected, got %s", luaL_typename(L, 1));
1552     l = list_alloc();
1553     if (l == NULL)
1554 	lua_pushnil(L);
1555     else
1556     {
1557 	luaV_newlist(L, l);
1558 	if (initarg) /* traverse table to init list */
1559 	{
1560 	    int notnil, i = 0;
1561 	    typval_T v;
1562 	    do
1563 	    {
1564 		lua_rawgeti(L, 1, ++i);
1565 		notnil = !lua_isnil(L, -1);
1566 		if (notnil)
1567 		{
1568 		    luaV_checktypval(L, -1, &v, "vim.list");
1569 		    list_append_tv(l, &v);
1570 		}
1571 		lua_pop(L, 1); /* value */
1572 	    } while (notnil);
1573 	}
1574     }
1575     return 1;
1576 }
1577 
1578     static int
1579 luaV_dict(lua_State *L)
1580 {
1581     dict_T *d;
1582     int initarg = !lua_isnoneornil(L, 1);
1583 
1584     if (initarg && lua_type(L, 1) != LUA_TTABLE)
1585 	luaL_error(L, "table expected, got %s", luaL_typename(L, 1));
1586     d = dict_alloc();
1587     if (d == NULL)
1588 	lua_pushnil(L);
1589     else
1590     {
1591 	luaV_newdict(L, d);
1592 	if (initarg) /* traverse table to init dict */
1593 	{
1594 	    lua_pushnil(L);
1595 	    while (lua_next(L, 1))
1596 	    {
1597 		char_u *key;
1598 		dictitem_T *di;
1599 		typval_T v;
1600 
1601 		lua_pushvalue(L, -2); /* dup key in case it's a number */
1602 		key = (char_u *) lua_tostring(L, -1);
1603 		if (key == NULL)
1604 		{
1605 		    lua_pushnil(L);
1606 		    return 1;
1607 		}
1608 		if (*key == NUL)
1609 		    luaL_error(L, "table has empty key");
1610 		luaV_checktypval(L, -2, &v, "vim.dict"); /* value */
1611 		di = dictitem_alloc(key);
1612 		if (di == NULL || dict_add(d, di) == FAIL)
1613 		{
1614 		    vim_free(di);
1615 		    lua_pushnil(L);
1616 		    return 1;
1617 		}
1618 		copy_tv(&v, &di->di_tv);
1619 		clear_tv(&v);
1620 		lua_pop(L, 2); /* key copy and value */
1621 	    }
1622 	}
1623     }
1624     return 1;
1625 }
1626 
1627     static int
1628 luaV_funcref(lua_State *L)
1629 {
1630     const char *name = luaL_checkstring(L, 1);
1631     /* note: not checking if function exists (needs function_exists) */
1632     if (name == NULL || *name == NUL || VIM_ISDIGIT(*name))
1633 	luaL_error(L, "invalid function name: %s", name);
1634     luaV_newfuncref(L, (char_u *) name);
1635     return 1;
1636 }
1637 
1638     static int
1639 luaV_buffer(lua_State *L)
1640 {
1641     buf_T *buf;
1642     if (lua_isstring(L, 1)) /* get by number or name? */
1643     {
1644 	if (lua_isnumber(L, 1)) /* by number? */
1645 	{
1646 	    int n = lua_tointeger(L, 1);
1647 	    FOR_ALL_BUFFERS(buf)
1648 		if (buf->b_fnum == n) break;
1649 	}
1650 	else // by name
1651 	{
1652 	    size_t l;
1653 	    const char *s = lua_tolstring(L, 1, &l);
1654 	    FOR_ALL_BUFFERS(buf)
1655 	    {
1656 		if (buf->b_ffname == NULL || buf->b_sfname == NULL)
1657 		{
1658 		    if (l == 0) break;
1659 		}
1660 		else if (strncmp(s, (char *)buf->b_ffname, l) == 0
1661 			|| strncmp(s, (char *)buf->b_sfname, l) == 0)
1662 		    break;
1663 	    }
1664 	}
1665     }
1666     else
1667 	buf = (lua_toboolean(L, 1)) ? firstbuf : curbuf; /* first buffer? */
1668     luaV_pushbuffer(L, buf);
1669     return 1;
1670 }
1671 
1672     static int
1673 luaV_window(lua_State *L)
1674 {
1675     win_T *win;
1676     if (lua_isnumber(L, 1)) /* get by number? */
1677     {
1678 	int n = lua_tointeger(L, 1);
1679 	for (win = firstwin; win != NULL; win = win->w_next, n--)
1680 	    if (n == 1) break;
1681     }
1682     else
1683 	win = (lua_toboolean(L, 1)) ? firstwin : curwin; /* first window? */
1684     luaV_pushwindow(L, win);
1685     return 1;
1686 }
1687 
1688     static int
1689 luaV_open(lua_State *L)
1690 {
1691     char_u *s = NULL;
1692 #ifdef HAVE_SANDBOX
1693     luaV_checksandbox(L);
1694 #endif
1695     if (lua_isstring(L, 1)) s = (char_u *) lua_tostring(L, 1);
1696     luaV_pushbuffer(L, buflist_new(s, NULL, 1L, BLN_LISTED));
1697     return 1;
1698 }
1699 
1700     static int
1701 luaV_type(lua_State *L)
1702 {
1703     luaL_checkany(L, 1);
1704     if (lua_type(L, 1) == LUA_TUSERDATA) /* check vim udata? */
1705     {
1706 	lua_settop(L, 1);
1707 	if (lua_getmetatable(L, 1))
1708 	{
1709 	    luaV_getfield(L, LUAVIM_LIST);
1710 	    if (lua_rawequal(L, -1, 2))
1711 	    {
1712 		lua_pushstring(L, "list");
1713 		return 1;
1714 	    }
1715 	    luaV_getfield(L, LUAVIM_DICT);
1716 	    if (lua_rawequal(L, -1, 2))
1717 	    {
1718 		lua_pushstring(L, "dict");
1719 		return 1;
1720 	    }
1721 	    luaV_getfield(L, LUAVIM_FUNCREF);
1722 	    if (lua_rawequal(L, -1, 2))
1723 	    {
1724 		lua_pushstring(L, "funcref");
1725 		return 1;
1726 	    }
1727 	    luaV_getfield(L, LUAVIM_BUFFER);
1728 	    if (lua_rawequal(L, -1, 2))
1729 	    {
1730 		lua_pushstring(L, "buffer");
1731 		return 1;
1732 	    }
1733 	    luaV_getfield(L, LUAVIM_WINDOW);
1734 	    if (lua_rawequal(L, -1, 2))
1735 	    {
1736 		lua_pushstring(L, "window");
1737 		return 1;
1738 	    }
1739 	}
1740     }
1741     lua_pushstring(L, luaL_typename(L, 1)); /* fallback */
1742     return 1;
1743 }
1744 
1745 static const luaL_Reg luaV_module[] = {
1746     {"command", luaV_command},
1747     {"eval", luaV_eval},
1748     {"beep", luaV_beep},
1749     {"line", luaV_line},
1750     {"list", luaV_list},
1751     {"dict", luaV_dict},
1752     {"funcref", luaV_funcref},
1753     {"buffer", luaV_buffer},
1754     {"window", luaV_window},
1755     {"open", luaV_open},
1756     {"type", luaV_type},
1757     {NULL, NULL}
1758 };
1759 
1760 /* for freeing list, dict, buffer and window objects; lightuserdata as arg */
1761     static int
1762 luaV_free(lua_State *L)
1763 {
1764     lua_pushnil(L);
1765     luaV_setudata(L, lua_touserdata(L, 1));
1766     return 0;
1767 }
1768 
1769     static int
1770 luaV_luaeval (lua_State *L)
1771 {
1772     luaL_Buffer b;
1773     size_t l;
1774     const char *str = lua_tolstring(L, 1, &l);
1775     typval_T *arg = (typval_T *) lua_touserdata(L, 2);
1776     typval_T *rettv = (typval_T *) lua_touserdata(L, 3);
1777     luaL_buffinit(L, &b);
1778     luaL_addlstring(&b, LUAVIM_EVALHEADER, sizeof(LUAVIM_EVALHEADER) - 1);
1779     luaL_addlstring(&b, str, l);
1780     luaL_pushresult(&b);
1781     str = lua_tolstring(L, -1, &l);
1782     if (luaL_loadbuffer(L, str, l, LUAVIM_EVALNAME)) /* compile error? */
1783     {
1784 	luaV_emsg(L);
1785 	return 0;
1786     }
1787     luaV_pushtypval(L, arg);
1788     if (lua_pcall(L, 1, 1, 0)) /* running error? */
1789     {
1790 	luaV_emsg(L);
1791 	return 0;
1792     }
1793     if (luaV_totypval(L, -1, rettv) == FAIL)
1794 	EMSG("luaeval: cannot convert value");
1795     return 0;
1796 }
1797 
1798     static int
1799 luaV_setref (lua_State *L)
1800 {
1801     int		copyID = lua_tointeger(L, 1);
1802     int		abort = FALSE;
1803     typval_T	tv;
1804 
1805     luaV_getfield(L, LUAVIM_LIST);
1806     luaV_getfield(L, LUAVIM_DICT);
1807     lua_pushnil(L);
1808     /* traverse cache table */
1809     while (!abort && lua_next(L, lua_upvalueindex(1)) != 0)
1810     {
1811 	lua_getmetatable(L, -1);
1812 	if (lua_rawequal(L, -1, 2)) /* list? */
1813 	{
1814 	    tv.v_type = VAR_LIST;
1815 	    tv.vval.v_list = (list_T *) lua_touserdata(L, 4); /* key */
1816 	    abort = set_ref_in_item(&tv, copyID, NULL, NULL);
1817 	}
1818 	else if (lua_rawequal(L, -1, 3)) /* dict? */
1819 	{
1820 	    tv.v_type = VAR_DICT;
1821 	    tv.vval.v_dict = (dict_T *) lua_touserdata(L, 4); /* key */
1822 	    abort = set_ref_in_item(&tv, copyID, NULL, NULL);
1823 	}
1824 	lua_pop(L, 2); /* metatable and value */
1825     }
1826     lua_pushinteger(L, abort);
1827     return 1;
1828 }
1829 
1830     static int
1831 luaopen_vim(lua_State *L)
1832 {
1833     /* set cache table */
1834     lua_newtable(L);
1835     lua_newtable(L);
1836     lua_pushstring(L, "v");
1837     lua_setfield(L, -2, "__mode");
1838     lua_setmetatable(L, -2); /* cache is weak-valued */
1839     /* print */
1840     lua_pushcfunction(L, luaV_print);
1841     lua_setglobal(L, "print");
1842     /* debug.debug */
1843     lua_getglobal(L, "debug");
1844     lua_pushcfunction(L, luaV_debug);
1845     lua_setfield(L, -2, "debug");
1846     lua_pop(L, 1);
1847     /* free */
1848     lua_pushlightuserdata(L, (void *) LUAVIM_FREE);
1849     lua_pushvalue(L, 1); /* cache table */
1850     lua_pushcclosure(L, luaV_free, 1);
1851     lua_rawset(L, LUA_REGISTRYINDEX);
1852     /* luaeval */
1853     lua_pushlightuserdata(L, (void *) LUAVIM_LUAEVAL);
1854     lua_pushvalue(L, 1); /* cache table */
1855     lua_pushcclosure(L, luaV_luaeval, 1);
1856     lua_rawset(L, LUA_REGISTRYINDEX);
1857     /* setref */
1858     lua_pushlightuserdata(L, (void *) LUAVIM_SETREF);
1859     lua_pushvalue(L, 1); /* cache table */
1860     lua_pushcclosure(L, luaV_setref, 1);
1861     lua_rawset(L, LUA_REGISTRYINDEX);
1862     /* register */
1863     luaV_newmetatable(L, LUAVIM_LIST);
1864     lua_pushvalue(L, 1);
1865     luaV_openlib(L, luaV_List_mt, 1);
1866     luaV_newmetatable(L, LUAVIM_DICT);
1867     lua_pushvalue(L, 1);
1868     luaV_openlib(L, luaV_Dict_mt, 1);
1869     luaV_newmetatable(L, LUAVIM_FUNCREF);
1870     lua_pushvalue(L, 1);
1871     luaV_openlib(L, luaV_Funcref_mt, 1);
1872     luaV_newmetatable(L, LUAVIM_BUFFER);
1873     lua_pushvalue(L, 1); /* cache table */
1874     luaV_openlib(L, luaV_Buffer_mt, 1);
1875     luaV_newmetatable(L, LUAVIM_WINDOW);
1876     lua_pushvalue(L, 1); /* cache table */
1877     luaV_openlib(L, luaV_Window_mt, 1);
1878     lua_newtable(L); /* vim table */
1879     lua_pushvalue(L, 1); /* cache table */
1880     luaV_openlib(L, luaV_module, 1);
1881     lua_setglobal(L, LUAVIM_NAME);
1882     return 0;
1883 }
1884 
1885     static lua_State *
1886 luaV_newstate(void)
1887 {
1888     lua_State *L = luaL_newstate();
1889     luaL_openlibs(L); /* core libs */
1890     lua_pushcfunction(L, luaopen_vim); /* vim */
1891     lua_call(L, 0, 0);
1892     return L;
1893 }
1894 
1895     static void
1896 luaV_setrange(lua_State *L, int line1, int line2)
1897 {
1898     lua_getglobal(L, LUAVIM_NAME);
1899     lua_pushinteger(L, line1);
1900     lua_setfield(L, -2, "firstline");
1901     lua_pushinteger(L, line2);
1902     lua_setfield(L, -2, "lastline");
1903     lua_pop(L, 1); /* vim table */
1904 }
1905 
1906 
1907 /* =======   Interface   ======= */
1908 
1909 static lua_State *L = NULL;
1910 
1911     static int
1912 lua_isopen(void)
1913 {
1914     return L != NULL;
1915 }
1916 
1917     static int
1918 lua_init(void)
1919 {
1920     if (!lua_isopen())
1921     {
1922 #ifdef DYNAMIC_LUA
1923 	if (!lua_enabled(TRUE))
1924 	{
1925 	    EMSG(_("Lua library cannot be loaded."));
1926 	    return FAIL;
1927 	}
1928 #endif
1929 	L = luaV_newstate();
1930     }
1931     return OK;
1932 }
1933 
1934     void
1935 lua_end(void)
1936 {
1937     if (lua_isopen())
1938     {
1939 	lua_close(L);
1940 	L = NULL;
1941 #ifdef DYNAMIC_LUA
1942 	end_dynamic_lua();
1943 #endif
1944     }
1945 }
1946 
1947 /* ex commands */
1948     void
1949 ex_lua(exarg_T *eap)
1950 {
1951     char *script;
1952     if (lua_init() == FAIL) return;
1953     script = (char *) script_get(eap, eap->arg);
1954     if (!eap->skip)
1955     {
1956 	char *s = (script) ? script :  (char *) eap->arg;
1957 	luaV_setrange(L, eap->line1, eap->line2);
1958 	if (luaL_loadbuffer(L, s, strlen(s), LUAVIM_CHUNKNAME)
1959 		|| lua_pcall(L, 0, 0, 0))
1960 	    luaV_emsg(L);
1961     }
1962     if (script != NULL) vim_free(script);
1963 }
1964 
1965     void
1966 ex_luado(exarg_T *eap)
1967 {
1968     linenr_T l;
1969     const char *s = (const char *) eap->arg;
1970     luaL_Buffer b;
1971     size_t len;
1972     buf_T *was_curbuf = curbuf;
1973 
1974     if (lua_init() == FAIL) return;
1975     if (u_save(eap->line1 - 1, eap->line2 + 1) == FAIL)
1976     {
1977 	EMSG(_("cannot save undo information"));
1978 	return;
1979     }
1980     luaV_setrange(L, eap->line1, eap->line2);
1981     luaL_buffinit(L, &b);
1982     luaL_addlstring(&b, "return function(line, linenr) ", 30); /* header */
1983     luaL_addlstring(&b, s, strlen(s));
1984     luaL_addlstring(&b, " end", 4); /* footer */
1985     luaL_pushresult(&b);
1986     s = lua_tolstring(L, -1, &len);
1987     if (luaL_loadbuffer(L, s, len, LUAVIM_CHUNKNAME))
1988     {
1989 	luaV_emsg(L);
1990 	lua_pop(L, 1); /* function body */
1991 	return;
1992     }
1993     lua_call(L, 0, 1);
1994     lua_replace(L, -2); /* function -> body */
1995     for (l = eap->line1; l <= eap->line2; l++)
1996     {
1997 	/* Check the line number, the command my have deleted lines. */
1998 	if (l > curbuf->b_ml.ml_line_count)
1999 	    break;
2000 
2001 	lua_pushvalue(L, -1); /* function */
2002 	luaV_pushline(L, curbuf, l); /* current line as arg */
2003 	lua_pushinteger(L, l); /* current line number as arg */
2004 	if (lua_pcall(L, 2, 1, 0))
2005 	{
2006 	    luaV_emsg(L);
2007 	    break;
2008 	}
2009 	/* Catch the command switching to another buffer. */
2010 	if (curbuf != was_curbuf)
2011 	    break;
2012 	if (lua_isstring(L, -1)) /* update line? */
2013 	{
2014 #ifdef HAVE_SANDBOX
2015 	    luaV_checksandbox(L);
2016 #endif
2017 	    ml_replace(l, luaV_toline(L, -1), TRUE);
2018 	    changed_bytes(l, 0);
2019 	    lua_pop(L, 1); /* result from luaV_toline */
2020 	}
2021 	lua_pop(L, 1); /* line */
2022     }
2023     lua_pop(L, 1); /* function */
2024     check_cursor();
2025     update_screen(NOT_VALID);
2026 }
2027 
2028     void
2029 ex_luafile(exarg_T *eap)
2030 {
2031     if (lua_init() == FAIL)
2032 	return;
2033     if (!eap->skip)
2034     {
2035 	luaV_setrange(L, eap->line1, eap->line2);
2036 	if (luaL_loadfile(L, (char *) eap->arg) || lua_pcall(L, 0, 0, 0))
2037 	    luaV_emsg(L);
2038     }
2039 }
2040 
2041 #define luaV_freetype(typ,tname) \
2042 	void \
2043     lua_##tname##_free(typ *o) \
2044     { \
2045 	if (!lua_isopen()) return; \
2046 	luaV_getfield(L, LUAVIM_FREE); \
2047 	lua_pushlightuserdata(L, (void *) o); \
2048 	lua_call(L, 1, 0); \
2049     }
2050 
2051 luaV_freetype(buf_T, buffer)
2052 luaV_freetype(win_T, window)
2053 
2054     void
2055 do_luaeval (char_u *str, typval_T *arg, typval_T *rettv)
2056 {
2057     lua_init();
2058     luaV_getfield(L, LUAVIM_LUAEVAL);
2059     lua_pushstring(L, (char *) str);
2060     lua_pushlightuserdata(L, (void *) arg);
2061     lua_pushlightuserdata(L, (void *) rettv);
2062     lua_call(L, 3, 0);
2063 }
2064 
2065     int
2066 set_ref_in_lua (int copyID)
2067 {
2068     int aborted = 0;
2069 
2070     if (lua_isopen())
2071     {
2072 	luaV_getfield(L, LUAVIM_SETREF);
2073 	/* call the function with 1 arg, getting 1 result back */
2074 	lua_pushinteger(L, copyID);
2075 	lua_call(L, 1, 1);
2076 	/* get the result */
2077 	aborted = lua_tointeger(L, -1);
2078 	/* pop result off the stack */
2079 	lua_pop(L, 1);
2080     }
2081     return aborted;
2082 }
2083 
2084 #endif
2085