]>
git.saurik.com Git - redis.git/blob - deps/lua/src/luaconf.h
2 ** $Id: luaconf.h,v 1.82.1.7 2008/02/11 16:25:08 roberto Exp $
3 ** Configuration file for Lua
4 ** See Copyright Notice in lua.h
16 ** ==================================================================
17 ** Search for "@@" to find all configurable definitions.
18 ** ===================================================================
23 @@ LUA_ANSI controls the use of non-ansi features.
24 ** CHANGE it (define it) if you want Lua to avoid the use of any
25 ** non-ansi feature or library.
27 #if defined(__STRICT_ANSI__)
32 #if !defined(LUA_ANSI) && defined(_WIN32)
36 #if defined(LUA_USE_LINUX)
38 #define LUA_USE_DLOPEN /* needs an extra library: -ldl */
39 #define LUA_USE_READLINE /* needs some extra libraries */
42 #if defined(LUA_USE_MACOSX)
44 #define LUA_DL_DYLD /* does not need extra library */
50 @@ LUA_USE_POSIX includes all functionallity listed as X/Open System
51 @* Interfaces Extension (XSI).
52 ** CHANGE it (define it) if your system is XSI compatible.
54 #if defined(LUA_USE_POSIX)
55 #define LUA_USE_MKSTEMP
56 #define LUA_USE_ISATTY
58 #define LUA_USE_ULONGJMP
63 @@ LUA_PATH and LUA_CPATH are the names of the environment variables that
64 @* Lua check to set its paths.
65 @@ LUA_INIT is the name of the environment variable that Lua
66 @* checks for initialization code.
67 ** CHANGE them if you want different names.
69 #define LUA_PATH "LUA_PATH"
70 #define LUA_CPATH "LUA_CPATH"
71 #define LUA_INIT "LUA_INIT"
75 @@ LUA_PATH_DEFAULT is the default path that Lua uses to look for
77 @@ LUA_CPATH_DEFAULT is the default path that Lua uses to look for
79 ** CHANGE them if your machine has a non-conventional directory
80 ** hierarchy or if you want to install your libraries in
81 ** non-conventional directories.
85 ** In Windows, any exclamation mark ('!') in the path is replaced by the
86 ** path of the directory of the executable file of the current process.
88 #define LUA_LDIR "!\\lua\\"
89 #define LUA_CDIR "!\\"
90 #define LUA_PATH_DEFAULT \
91 ".\\?.lua;" LUA_LDIR"?.lua;" LUA_LDIR"?\\init.lua;" \
92 LUA_CDIR"?.lua;" LUA_CDIR"?\\init.lua"
93 #define LUA_CPATH_DEFAULT \
94 ".\\?.dll;" LUA_CDIR"?.dll;" LUA_CDIR"loadall.dll"
97 #define LUA_ROOT "/usr/local/"
98 #define LUA_LDIR LUA_ROOT "share/lua/5.1/"
99 #define LUA_CDIR LUA_ROOT "lib/lua/5.1/"
100 #define LUA_PATH_DEFAULT \
101 "./?.lua;" LUA_LDIR"?.lua;" LUA_LDIR"?/init.lua;" \
102 LUA_CDIR"?.lua;" LUA_CDIR"?/init.lua"
103 #define LUA_CPATH_DEFAULT \
104 "./?.so;" LUA_CDIR"?.so;" LUA_CDIR"loadall.so"
109 @@ LUA_DIRSEP is the directory separator (for submodules).
110 ** CHANGE it if your machine does not use "/" as the directory separator
111 ** and is not Windows. (On Windows Lua automatically uses "\".)
114 #define LUA_DIRSEP "\\"
116 #define LUA_DIRSEP "/"
121 @@ LUA_PATHSEP is the character that separates templates in a path.
122 @@ LUA_PATH_MARK is the string that marks the substitution points in a
124 @@ LUA_EXECDIR in a Windows path is replaced by the executable's
126 @@ LUA_IGMARK is a mark to ignore all before it when bulding the
127 @* luaopen_ function name.
128 ** CHANGE them if for some reason your system cannot use those
129 ** characters. (E.g., if one of those characters is a common character
130 ** in file/directory names.) Probably you do not need to change them.
132 #define LUA_PATHSEP ";"
133 #define LUA_PATH_MARK "?"
134 #define LUA_EXECDIR "!"
135 #define LUA_IGMARK "-"
139 @@ LUA_INTEGER is the integral type used by lua_pushinteger/lua_tointeger.
140 ** CHANGE that if ptrdiff_t is not adequate on your machine. (On most
141 ** machines, ptrdiff_t gives a good choice between int or long.)
143 #define LUA_INTEGER ptrdiff_t
147 @@ LUA_API is a mark for all core API functions.
148 @@ LUALIB_API is a mark for all standard library functions.
149 ** CHANGE them if you need to define those functions in some special way.
150 ** For instance, if you want to create one Windows DLL with the core and
151 ** the libraries, you may want to use the following definition (define
152 ** LUA_BUILD_AS_DLL to get it).
154 #if defined(LUA_BUILD_AS_DLL)
156 #if defined(LUA_CORE) || defined(LUA_LIB)
157 #define LUA_API __declspec(dllexport)
159 #define LUA_API __declspec(dllimport)
164 #define LUA_API extern
168 /* more often than not the libs go together with the core */
169 #define LUALIB_API LUA_API
173 @@ LUAI_FUNC is a mark for all extern functions that are not to be
174 @* exported to outside modules.
175 @@ LUAI_DATA is a mark for all extern (const) variables that are not to
176 @* be exported to outside modules.
177 ** CHANGE them if you need to mark them in some special way. Elf/gcc
178 ** (versions 3.2 and later) mark them as "hidden" to optimize access
179 ** when Lua is compiled as a shared library.
181 #if defined(luaall_c)
182 #define LUAI_FUNC static
183 #define LUAI_DATA /* empty */
185 #elif defined(__GNUC__) && ((__GNUC__*100 + __GNUC_MINOR__) >= 302) && \
187 #define LUAI_FUNC __attribute__((visibility("hidden"))) extern
188 #define LUAI_DATA LUAI_FUNC
191 #define LUAI_FUNC extern
192 #define LUAI_DATA extern
198 @@ LUA_QL describes how error messages quote program elements.
199 ** CHANGE it if you want a different appearance.
201 #define LUA_QL(x) "'" x "'"
202 #define LUA_QS LUA_QL("%s")
206 @@ LUA_IDSIZE gives the maximum size for the description of the source
207 @* of a function in debug information.
208 ** CHANGE it if you want a different size.
210 #define LUA_IDSIZE 60
214 ** {==================================================================
215 ** Stand-alone configuration
216 ** ===================================================================
219 #if defined(lua_c) || defined(luaall_c)
222 @@ lua_stdin_is_tty detects whether the standard input is a 'tty' (that
223 @* is, whether we're running lua interactively).
224 ** CHANGE it if you have a better definition for non-POSIX/non-Windows
227 #if defined(LUA_USE_ISATTY)
229 #define lua_stdin_is_tty() isatty(0)
230 #elif defined(LUA_WIN)
233 #define lua_stdin_is_tty() _isatty(_fileno(stdin))
235 #define lua_stdin_is_tty() 1 /* assume stdin is a tty */
240 @@ LUA_PROMPT is the default prompt used by stand-alone Lua.
241 @@ LUA_PROMPT2 is the default continuation prompt used by stand-alone Lua.
242 ** CHANGE them if you want different prompts. (You can also change the
243 ** prompts dynamically, assigning to globals _PROMPT/_PROMPT2.)
245 #define LUA_PROMPT "> "
246 #define LUA_PROMPT2 ">> "
250 @@ LUA_PROGNAME is the default name for the stand-alone Lua program.
251 ** CHANGE it if your stand-alone interpreter has a different name and
252 ** your system is not able to detect that name automatically.
254 #define LUA_PROGNAME "lua"
258 @@ LUA_MAXINPUT is the maximum length for an input line in the
259 @* stand-alone interpreter.
260 ** CHANGE it if you need longer lines.
262 #define LUA_MAXINPUT 512
266 @@ lua_readline defines how to show a prompt and then read a line from
267 @* the standard input.
268 @@ lua_saveline defines how to "save" a read line in a "history".
269 @@ lua_freeline defines how to free a line read by lua_readline.
270 ** CHANGE them if you want to improve this functionality (e.g., by using
271 ** GNU readline and history facilities).
273 #if defined(LUA_USE_READLINE)
275 #include <readline/readline.h>
276 #include <readline/history.h>
277 #define lua_readline(L,b,p) ((void)L, ((b)=readline(p)) != NULL)
278 #define lua_saveline(L,idx) \
279 if (lua_strlen(L,idx) > 0) /* non-empty line? */ \
280 add_history(lua_tostring(L, idx)); /* add it to history */
281 #define lua_freeline(L,b) ((void)L, free(b))
283 #define lua_readline(L,b,p) \
284 ((void)L, fputs(p, stdout), fflush(stdout), /* show prompt */ \
285 fgets(b, LUA_MAXINPUT, stdin) != NULL) /* get line */
286 #define lua_saveline(L,idx) { (void)L; (void)idx; }
287 #define lua_freeline(L,b) { (void)L; (void)b; }
292 /* }================================================================== */
296 @@ LUAI_GCPAUSE defines the default pause between garbage-collector cycles
298 ** CHANGE it if you want the GC to run faster or slower (higher values
299 ** mean larger pauses which mean slower collection.) You can also change
300 ** this value dynamically.
302 #define LUAI_GCPAUSE 200 /* 200% (wait memory to double before next GC) */
306 @@ LUAI_GCMUL defines the default speed of garbage collection relative to
307 @* memory allocation as a percentage.
308 ** CHANGE it if you want to change the granularity of the garbage
309 ** collection. (Higher values mean coarser collections. 0 represents
310 ** infinity, where each step performs a full collection.) You can also
311 ** change this value dynamically.
313 #define LUAI_GCMUL 200 /* GC runs 'twice the speed' of memory allocation */
318 @@ LUA_COMPAT_GETN controls compatibility with old getn behavior.
319 ** CHANGE it (define it) if you want exact compatibility with the
320 ** behavior of setn/getn in Lua 5.0.
322 #undef LUA_COMPAT_GETN
325 @@ LUA_COMPAT_LOADLIB controls compatibility about global loadlib.
326 ** CHANGE it to undefined as soon as you do not need a global 'loadlib'
327 ** function (the function is still available as 'package.loadlib').
329 #undef LUA_COMPAT_LOADLIB
332 @@ LUA_COMPAT_VARARG controls compatibility with old vararg feature.
333 ** CHANGE it to undefined as soon as your programs use only '...' to
334 ** access vararg parameters (instead of the old 'arg' table).
336 #define LUA_COMPAT_VARARG
339 @@ LUA_COMPAT_MOD controls compatibility with old math.mod function.
340 ** CHANGE it to undefined as soon as your programs use 'math.fmod' or
341 ** the new '%' operator instead of 'math.mod'.
343 #define LUA_COMPAT_MOD
346 @@ LUA_COMPAT_LSTR controls compatibility with old long string nesting
348 ** CHANGE it to 2 if you want the old behaviour, or undefine it to turn
349 ** off the advisory error when nesting [[...]].
351 #define LUA_COMPAT_LSTR 1
354 @@ LUA_COMPAT_GFIND controls compatibility with old 'string.gfind' name.
355 ** CHANGE it to undefined as soon as you rename 'string.gfind' to
358 #define LUA_COMPAT_GFIND
361 @@ LUA_COMPAT_OPENLIB controls compatibility with old 'luaL_openlib'
363 ** CHANGE it to undefined as soon as you replace to 'luaL_register'
364 ** your uses of 'luaL_openlib'
366 #define LUA_COMPAT_OPENLIB
371 @@ luai_apicheck is the assert macro used by the Lua-C API.
372 ** CHANGE luai_apicheck if you want Lua to perform some checks in the
373 ** parameters it gets from API calls. This may slow down the interpreter
374 ** a bit, but may be quite useful when debugging C code that interfaces
375 ** with Lua. A useful redefinition is to use assert.h.
377 #if defined(LUA_USE_APICHECK)
379 #define luai_apicheck(L,o) { (void)L; assert(o); }
381 #define luai_apicheck(L,o) { (void)L; }
386 @@ LUAI_BITSINT defines the number of bits in an int.
387 ** CHANGE here if Lua cannot automatically detect the number of bits of
388 ** your machine. Probably you do not need to change this.
390 /* avoid overflows in comparison */
391 #if INT_MAX-20 < 32760
392 #define LUAI_BITSINT 16
393 #elif INT_MAX > 2147483640L
394 /* int has at least 32 bits */
395 #define LUAI_BITSINT 32
397 #error "you must define LUA_BITSINT with number of bits in an integer"
402 @@ LUAI_UINT32 is an unsigned integer with at least 32 bits.
403 @@ LUAI_INT32 is an signed integer with at least 32 bits.
404 @@ LUAI_UMEM is an unsigned integer big enough to count the total
405 @* memory used by Lua.
406 @@ LUAI_MEM is a signed integer big enough to count the total memory
408 ** CHANGE here if for some weird reason the default definitions are not
409 ** good enough for your machine. (The definitions in the 'else'
410 ** part always works, but may waste space on machines with 64-bit
411 ** longs.) Probably you do not need to change this.
413 #if LUAI_BITSINT >= 32
414 #define LUAI_UINT32 unsigned int
415 #define LUAI_INT32 int
416 #define LUAI_MAXINT32 INT_MAX
417 #define LUAI_UMEM size_t
418 #define LUAI_MEM ptrdiff_t
421 #define LUAI_UINT32 unsigned long
422 #define LUAI_INT32 long
423 #define LUAI_MAXINT32 LONG_MAX
424 #define LUAI_UMEM unsigned long
425 #define LUAI_MEM long
430 @@ LUAI_MAXCALLS limits the number of nested calls.
431 ** CHANGE it if you need really deep recursive calls. This limit is
432 ** arbitrary; its only purpose is to stop infinite recursion before
433 ** exhausting memory.
435 #define LUAI_MAXCALLS 20000
439 @@ LUAI_MAXCSTACK limits the number of Lua stack slots that a C function
441 ** CHANGE it if you need lots of (Lua) stack space for your C
442 ** functions. This limit is arbitrary; its only purpose is to stop C
443 ** functions to consume unlimited stack space. (must be smaller than
444 ** -LUA_REGISTRYINDEX)
446 #define LUAI_MAXCSTACK 8000
451 ** {==================================================================
452 ** CHANGE (to smaller values) the following definitions if your system
453 ** has a small C stack. (Or you may want to change them to larger
454 ** values if your system has a large C stack and these limits are
455 ** too rigid for you.) Some of these constants control the size of
456 ** stack-allocated arrays used by the compiler or the interpreter, while
457 ** others limit the maximum number of recursive calls that the compiler
458 ** or the interpreter can perform. Values too large may cause a C stack
459 ** overflow for some forms of deep constructs.
460 ** ===================================================================
465 @@ LUAI_MAXCCALLS is the maximum depth for nested C calls (short) and
466 @* syntactical nested non-terminals in a program.
468 #define LUAI_MAXCCALLS 200
472 @@ LUAI_MAXVARS is the maximum number of local variables per function
473 @* (must be smaller than 250).
475 #define LUAI_MAXVARS 200
479 @@ LUAI_MAXUPVALUES is the maximum number of upvalues per function
480 @* (must be smaller than 250).
482 #define LUAI_MAXUPVALUES 60
486 @@ LUAL_BUFFERSIZE is the buffer size used by the lauxlib buffer system.
488 #define LUAL_BUFFERSIZE BUFSIZ
490 /* }================================================================== */
496 ** {==================================================================
497 @@ LUA_NUMBER is the type of numbers in Lua.
498 ** CHANGE the following definitions only if you want to build Lua
499 ** with a number type different from double. You may also need to
500 ** change lua_number2int & lua_number2integer.
501 ** ===================================================================
504 #define LUA_NUMBER_DOUBLE
505 #define LUA_NUMBER double
508 @@ LUAI_UACNUMBER is the result of an 'usual argument conversion'
511 #define LUAI_UACNUMBER double
515 @@ LUA_NUMBER_SCAN is the format for reading numbers.
516 @@ LUA_NUMBER_FMT is the format for writing numbers.
517 @@ lua_number2str converts a number to a string.
518 @@ LUAI_MAXNUMBER2STR is maximum size of previous conversion.
519 @@ lua_str2number converts a string to a number.
521 #define LUA_NUMBER_SCAN "%lf"
522 #define LUA_NUMBER_FMT "%.14g"
523 #define lua_number2str(s,n) sprintf((s), LUA_NUMBER_FMT, (n))
524 #define LUAI_MAXNUMBER2STR 32 /* 16 digits, sign, point, and \0 */
525 #define lua_str2number(s,p) strtod((s), (p))
529 @@ The luai_num* macros define the primitive operations over numbers.
531 #if defined(LUA_CORE)
533 #define luai_numadd(a,b) ((a)+(b))
534 #define luai_numsub(a,b) ((a)-(b))
535 #define luai_nummul(a,b) ((a)*(b))
536 #define luai_numdiv(a,b) ((a)/(b))
537 #define luai_nummod(a,b) ((a) - floor((a)/(b))*(b))
538 #define luai_numpow(a,b) (pow(a,b))
539 #define luai_numunm(a) (-(a))
540 #define luai_numeq(a,b) ((a)==(b))
541 #define luai_numlt(a,b) ((a)<(b))
542 #define luai_numle(a,b) ((a)<=(b))
543 #define luai_numisnan(a) (!luai_numeq((a), (a)))
548 @@ lua_number2int is a macro to convert lua_Number to int.
549 @@ lua_number2integer is a macro to convert lua_Number to lua_Integer.
550 ** CHANGE them if you know a faster way to convert a lua_Number to
551 ** int (with any rounding method and without throwing errors) in your
552 ** system. In Pentium machines, a naive typecast from double to int
553 ** in C is extremely slow, so any alternative is worth trying.
556 /* On a Pentium, resort to a trick */
557 #if defined(LUA_NUMBER_DOUBLE) && !defined(LUA_ANSI) && !defined(__SSE2__) && \
558 (defined(__i386) || defined (_M_IX86) || defined(__i386__))
560 /* On a Microsoft compiler, use assembler */
561 #if defined(_MSC_VER)
563 #define lua_number2int(i,d) __asm fld d __asm fistp i
564 #define lua_number2integer(i,n) lua_number2int(i, n)
566 /* the next trick should work on any Pentium, but sometimes clashes
567 with a DirectX idiosyncrasy */
570 union luai_Cast
{ double l_d
; long l_l
; };
571 #define lua_number2int(i,d) \
572 { volatile union luai_Cast u; u.l_d = (d) + 6755399441055744.0; (i) = u.l_l; }
573 #define lua_number2integer(i,n) lua_number2int(i, n)
578 /* this option always works, but may be slow */
580 #define lua_number2int(i,d) ((i)=(int)(d))
581 #define lua_number2integer(i,d) ((i)=(lua_Integer)(d))
585 /* }================================================================== */
589 @@ LUAI_USER_ALIGNMENT_T is a type that requires maximum alignment.
590 ** CHANGE it if your system requires alignments larger than double. (For
591 ** instance, if your system supports long doubles and they must be
592 ** aligned in 16-byte boundaries, then you should add long double in the
593 ** union.) Probably you do not need to change this.
595 #define LUAI_USER_ALIGNMENT_T union { double u; void *s; long l; }
599 @@ LUAI_THROW/LUAI_TRY define how Lua does exception handling.
600 ** CHANGE them if you prefer to use longjmp/setjmp even with C++
601 ** or if want/don't to use _longjmp/_setjmp instead of regular
602 ** longjmp/setjmp. By default, Lua handles errors with exceptions when
603 ** compiling as C++ code, with _longjmp/_setjmp when asked to use them,
604 ** and with longjmp/setjmp otherwise.
606 #if defined(__cplusplus)
608 #define LUAI_THROW(L,c) throw(c)
609 #define LUAI_TRY(L,c,a) try { a } catch(...) \
610 { if ((c)->status == 0) (c)->status = -1; }
611 #define luai_jmpbuf int /* dummy variable */
613 #elif defined(LUA_USE_ULONGJMP)
614 /* in Unix, try _longjmp/_setjmp (more efficient) */
615 #define LUAI_THROW(L,c) _longjmp((c)->b, 1)
616 #define LUAI_TRY(L,c,a) if (_setjmp((c)->b) == 0) { a }
617 #define luai_jmpbuf jmp_buf
620 /* default handling with long jumps */
621 #define LUAI_THROW(L,c) longjmp((c)->b, 1)
622 #define LUAI_TRY(L,c,a) if (setjmp((c)->b) == 0) { a }
623 #define luai_jmpbuf jmp_buf
629 @@ LUA_MAXCAPTURES is the maximum number of captures that a pattern
630 @* can do during pattern-matching.
631 ** CHANGE it if you need more captures. This limit is arbitrary.
633 #define LUA_MAXCAPTURES 32
637 @@ lua_tmpnam is the function that the OS library uses to create a
639 @@ LUA_TMPNAMBUFSIZE is the maximum size of a name created by lua_tmpnam.
640 ** CHANGE them if you have an alternative to tmpnam (which is considered
641 ** insecure) or if you want the original tmpnam anyway. By default, Lua
642 ** uses tmpnam except when POSIX is available, where it uses mkstemp.
644 #if defined(loslib_c) || defined(luaall_c)
646 #if defined(LUA_USE_MKSTEMP)
648 #define LUA_TMPNAMBUFSIZE 32
649 #define lua_tmpnam(b,e) { \
650 strcpy(b, "/tmp/lua_XXXXXX"); \
652 if (e != -1) close(e); \
656 #define LUA_TMPNAMBUFSIZE L_tmpnam
657 #define lua_tmpnam(b,e) { e = (tmpnam(b) == NULL); }
664 @@ lua_popen spawns a new process connected to the current one through
666 ** CHANGE it if you have a way to implement it in your system.
668 #if defined(LUA_USE_POPEN)
670 #define lua_popen(L,c,m) ((void)L, fflush(NULL), popen(c,m))
671 #define lua_pclose(L,file) ((void)L, (pclose(file) != -1))
673 #elif defined(LUA_WIN)
675 #define lua_popen(L,c,m) ((void)L, _popen(c,m))
676 #define lua_pclose(L,file) ((void)L, (_pclose(file) != -1))
680 #define lua_popen(L,c,m) ((void)((void)c, m), \
681 luaL_error(L, LUA_QL("popen") " not supported"), (FILE*)0)
682 #define lua_pclose(L,file) ((void)((void)L, file), 0)
687 @@ LUA_DL_* define which dynamic-library system Lua should use.
688 ** CHANGE here if Lua has problems choosing the appropriate
689 ** dynamic-library system for your platform (either Windows' DLL, Mac's
690 ** dyld, or Unix's dlopen). If your system is some kind of Unix, there
691 ** is a good chance that it has dlopen, so LUA_DL_DLOPEN will work for
692 ** it. To use dlopen you also need to adapt the src/Makefile (probably
693 ** adding -ldl to the linker options), so Lua does not select it
694 ** automatically. (When you change the makefile to add -ldl, you must
695 ** also add -DLUA_USE_DLOPEN.)
696 ** If you do not want any kind of dynamic library, undefine all these
698 ** By default, _WIN32 gets LUA_DL_DLL and MAC OS X gets LUA_DL_DYLD.
700 #if defined(LUA_USE_DLOPEN)
701 #define LUA_DL_DLOPEN
710 @@ LUAI_EXTRASPACE allows you to add user-specific data in a lua_State
711 @* (the data goes just *before* the lua_State pointer).
712 ** CHANGE (define) this if you really need that. This value must be
713 ** a multiple of the maximum alignment required for your machine.
715 #define LUAI_EXTRASPACE 0
719 @@ luai_userstate* allow user-specific actions on threads.
720 ** CHANGE them if you defined LUAI_EXTRASPACE and need to do something
721 ** extra when a thread is created/deleted/resumed/yielded.
723 #define luai_userstateopen(L) ((void)L)
724 #define luai_userstateclose(L) ((void)L)
725 #define luai_userstatethread(L,L1) ((void)L)
726 #define luai_userstatefree(L) ((void)L)
727 #define luai_userstateresume(L,n) ((void)L)
728 #define luai_userstateyield(L,n) ((void)L)
732 @@ LUA_INTFRMLEN is the length modifier for integer conversions
733 @* in 'string.format'.
734 @@ LUA_INTFRM_T is the integer type correspoding to the previous length
736 ** CHANGE them if your system supports long long or does not support long.
739 #if defined(LUA_USELONGLONG)
741 #define LUA_INTFRMLEN "ll"
742 #define LUA_INTFRM_T long long
746 #define LUA_INTFRMLEN "l"
747 #define LUA_INTFRM_T long
753 /* =================================================================== */
756 ** Local configuration. You can use this space to add your redefinitions
757 ** without modifying the main part of the file.