lua/doxygen/lctype_8h_source.html

/*

** $Id: lctype.h $

** 'ctype' functions for Lua

** See Copyright Notice in lua.h

*/


#ifndef lctype_h

#define lctype_h


#include "lua.h"


/*

** WARNING: the functions defined here do not necessarily correspond

** to the similar functions in the standard C ctype.h. They are

** optimized for the specific needs of Lua.

*/


#if !defined(LUA_USE_CTYPE)


#if 'A' == 65 && '0' == 48

/* ASCII case: can use its own tables; faster and fixed */

#define LUA_USE_CTYPE   0

#else

/* must use standard C ctype */

#define LUA_USE_CTYPE   1

#endif


#endif


#if !LUA_USE_CTYPE  /* { */


#include <limits.h>


#include "llimits.h"


#define ALPHABIT    0

#define DIGITBIT    1

#define PRINTBIT    2

#define SPACEBIT    3

#define XDIGITBIT   4


#define MASK(B)     (1 << (B))


/*

** add 1 to char to allow index -1 (EOZ)

*/

#define testprop(c,p)   (luai_ctype_[(c)+1] & (p))


/*

** 'lalpha' (Lua alphabetic) and 'lalnum' (Lua alphanumeric) both include '_'

*/

#define lislalpha(c)    testprop(c, MASK(ALPHABIT))

#define lislalnum(c)    testprop(c, (MASK(ALPHABIT) | MASK(DIGITBIT)))

#define lisdigit(c) testprop(c, MASK(DIGITBIT))

#define lisspace(c) testprop(c, MASK(SPACEBIT))

#define lisprint(c) testprop(c, MASK(PRINTBIT))

#define lisxdigit(c)    testprop(c, MASK(XDIGITBIT))


/*

** In ASCII, this 'ltolower' is correct for alphabetic characters and

** for '.'. That is enough for Lua needs. ('check_exp' ensures that

** the character either is an upper-case letter or is unchanged by

** the transformation, which holds for lower-case letters and '.'.)

*/

#define ltolower(c)  \

  check_exp(('A' <= (c) && (c) <= 'Z') || (c) == ((c) | ('A' ^ 'a')),  \

            (c) | ('A' ^ 'a'))


/* one entry for each character and for -1 (EOZ) */

LUAI_DDEC(const lu_byte luai_ctype_[UCHAR_MAX + 2];)


#else           /* }{ */


/*

** use standard C ctypes

*/


#include <ctype.h>


#define lislalpha(c)    (isalpha(c) || (c) == '_')

#define lislalnum(c)    (isalnum(c) || (c) == '_')

#define lisdigit(c) (isdigit(c))

#define lisspace(c) (isspace(c))

#define lisprint(c) (isprint(c))

#define lisxdigit(c)    (isxdigit(c))


#define ltolower(c) (tolower(c))


#endif          /* } */


#endif