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Extending a C++ Application with Lua 5.2

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4 Aug 2013CPOL13 min read 56.8K   1.5K   66  
Using a subset of the available Lua 5.2 C interface to extend a C++ application with Lua.
/*
** $Id: lauxlib.h,v 1.120 2011/11/29 15:55:08 roberto Exp $
** Auxiliary functions for building Lua libraries
** See Copyright Notice in lua.h
*/


#ifndef lauxlib_h
#define lauxlib_h


#include <stddef.h>
#include <stdio.h>

#include "lua.h"



/* extra error code for `luaL_load' */
#define LUA_ERRFILE     (LUA_ERRERR+1)


typedef struct luaL_Reg {
  const char *name;
  lua_CFunction func;
} luaL_Reg;


LUALIB_API void (luaL_checkversion_) (lua_State *L, lua_Number ver);
#define luaL_checkversion(L)	luaL_checkversion_(L, LUA_VERSION_NUM)

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 const char *(luaL_tolstring) (lua_State *L, int idx, size_t *len);
LUALIB_API int (luaL_argerror) (lua_State *L, int numarg, const char *extramsg);
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);
LUALIB_API lua_Number (luaL_checknumber) (lua_State *L, int numArg);
LUALIB_API lua_Number (luaL_optnumber) (lua_State *L, int nArg, lua_Number def);

LUALIB_API lua_Integer (luaL_checkinteger) (lua_State *L, int numArg);
LUALIB_API lua_Integer (luaL_optinteger) (lua_State *L, int nArg,
                                          lua_Integer def);
LUALIB_API lua_Unsigned (luaL_checkunsigned) (lua_State *L, int numArg);
LUALIB_API lua_Unsigned (luaL_optunsigned) (lua_State *L, int numArg,
                                            lua_Unsigned def);

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_setmetatable) (lua_State *L, const char *tname);
LUALIB_API void *(luaL_testudata) (lua_State *L, int ud, 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, ...);

LUALIB_API int (luaL_checkoption) (lua_State *L, int narg, const char *def,
                                   const char *const lst[]);

LUALIB_API int (luaL_fileresult) (lua_State *L, int stat, const char *fname);
LUALIB_API int (luaL_execresult) (lua_State *L, int stat);

/* pre-defined references */
#define LUA_NOREF       (-2)
#define LUA_REFNIL      (-1)

LUALIB_API int (luaL_ref) (lua_State *L, int t);
LUALIB_API void (luaL_unref) (lua_State *L, int t, int ref);

LUALIB_API int (luaL_loadfilex) (lua_State *L, const char *filename,
                                               const char *mode);

#define luaL_loadfile(L,f)	luaL_loadfilex(L,f,NULL)

LUALIB_API int (luaL_loadbufferx) (lua_State *L, const char *buff, size_t sz,
                                   const char *name, const char *mode);
LUALIB_API int (luaL_loadstring) (lua_State *L, const char *s);

LUALIB_API lua_State *(luaL_newstate) (void);

LUALIB_API int (luaL_len) (lua_State *L, int idx);

LUALIB_API const char *(luaL_gsub) (lua_State *L, const char *s, const char *p,
                                                  const char *r);

LUALIB_API void (luaL_setfuncs) (lua_State *L, const luaL_Reg *l, int nup);

LUALIB_API int (luaL_getsubtable) (lua_State *L, int idx, const char *fname);

LUALIB_API void (luaL_traceback) (lua_State *L, lua_State *L1,
                                  const char *msg, int level);

LUALIB_API void (luaL_requiref) (lua_State *L, const char *modname,
                                 lua_CFunction openf, int glb);

/*
** ===============================================================
** some useful macros
** ===============================================================
*/


#define luaL_newlibtable(L,l)	\
  lua_createtable(L, 0, sizeof(l)/sizeof((l)[0]) - 1)

#define luaL_newlib(L,l)	(luaL_newlibtable(L,l), luaL_setfuncs(L,l,0))

#define luaL_argcheck(L, cond,numarg,extramsg)	\
		((void)((cond) || luaL_argerror(L, (numarg), (extramsg))))
#define luaL_checkstring(L,n)	(luaL_checklstring(L, (n), NULL))
#define luaL_optstring(L,n,d)	(luaL_optlstring(L, (n), (d), NULL))
#define luaL_checkint(L,n)	((int)luaL_checkinteger(L, (n)))
#define luaL_optint(L,n,d)	((int)luaL_optinteger(L, (n), (d)))
#define luaL_checklong(L,n)	((long)luaL_checkinteger(L, (n)))
#define luaL_optlong(L,n,d)	((long)luaL_optinteger(L, (n), (d)))

#define luaL_typename(L,i)	lua_typename(L, lua_type(L,(i)))

#define luaL_dofile(L, fn) \
	(luaL_loadfile(L, fn) || lua_pcall(L, 0, LUA_MULTRET, 0))

#define luaL_dostring(L, s) \
	(luaL_loadstring(L, s) || lua_pcall(L, 0, LUA_MULTRET, 0))

#define luaL_getmetatable(L,n)	(lua_getfield(L, LUA_REGISTRYINDEX, (n)))

#define luaL_opt(L,f,n,d)	(lua_isnoneornil(L,(n)) ? (d) : f(L,(n)))

#define luaL_loadbuffer(L,s,sz,n)	luaL_loadbufferx(L,s,sz,n,NULL)


/*
** {======================================================
** Generic Buffer manipulation
** =======================================================
*/

typedef struct luaL_Buffer {
  char *b;  /* buffer address */
  size_t size;  /* buffer size */
  size_t n;  /* number of characters in buffer */
  lua_State *L;
  char initb[LUAL_BUFFERSIZE];  /* initial buffer */
} luaL_Buffer;


#define luaL_addchar(B,c) \
  ((void)((B)->n < (B)->size || luaL_prepbuffsize((B), 1)), \
   ((B)->b[(B)->n++] = (c)))

#define luaL_addsize(B,s)	((B)->n += (s))

LUALIB_API void (luaL_buffinit) (lua_State *L, luaL_Buffer *B);
LUALIB_API char *(luaL_prepbuffsize) (luaL_Buffer *B, size_t sz);
LUALIB_API void (luaL_addlstring) (luaL_Buffer *B, const char *s, size_t l);
LUALIB_API void (luaL_addstring) (luaL_Buffer *B, const char *s);
LUALIB_API void (luaL_addvalue) (luaL_Buffer *B);
LUALIB_API void (luaL_pushresult) (luaL_Buffer *B);
LUALIB_API void (luaL_pushresultsize) (luaL_Buffer *B, size_t sz);
LUALIB_API char *(luaL_buffinitsize) (lua_State *L, luaL_Buffer *B, size_t sz);

#define luaL_prepbuffer(B)	luaL_prepbuffsize(B, LUAL_BUFFERSIZE)

/* }====================================================== */



/*
** {======================================================
** File handles for IO library
** =======================================================
*/

/*
** A file handle is a userdata with metatable 'LUA_FILEHANDLE' and
** initial structure 'luaL_Stream' (it may contain other fields
** after that initial structure).
*/

#define LUA_FILEHANDLE          "FILE*"


typedef struct luaL_Stream {
  FILE *f;  /* stream (NULL for incompletely created streams) */
  lua_CFunction closef;  /* to close stream (NULL for closed streams) */
} luaL_Stream;

/* }====================================================== */



/* compatibility with old module system */
#if defined(LUA_COMPAT_MODULE)

LUALIB_API void (luaL_pushmodule) (lua_State *L, const char *modname,
                                   int sizehint);
LUALIB_API void (luaL_openlib) (lua_State *L, const char *libname,
                                const luaL_Reg *l, int nup);

#define luaL_register(L,n,l)	(luaL_openlib(L,(n),(l),0))

#endif


#endif


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License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Retired Georgia Southern University
United States United States
Team lead for a point of sale software application written in C and C++. Previous experience with Nortel Networks on software for telecommunications products as well as Program Management.

Education:
BS Computer Science
MBA
Masters in Project Management

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