/* General utilities <stdlib.h>

   This file is part of the Public Domain C Library (PDCLib).
   Permission is granted to use, modify, and / or redistribute at will.
*/

#ifndef _PDCLIB_STDLIB_H
#define _PDCLIB_STDLIB_H _PDCLIB_STDLIB_H
#include "_PDCLIB_int.h"

#ifdef __cplusplus
extern "C" {
#endif

#ifndef _PDCLIB_SIZE_T_DEFINED
#define _PDCLIB_SIZE_T_DEFINED _PDCLIB_SIZE_T_DEFINED
typedef _PDCLIB_size_t size_t;
#endif

#ifndef _PDCLIB_NULL_DEFINED
#define _PDCLIB_NULL_DEFINED _PDCLIB_NULL_DEFINED
#define NULL _PDCLIB_NULL
#endif

#ifndef __cplusplus

#ifndef _PDCLIB_WCHAR_T_DEFINED
#define _PDCLIB_WCHAR_T_DEFINED _PDCLIB_WCHAR_T_DEFINED
typedef _PDCLIB_wchar_t wchar_t;
#endif

#endif

#ifndef _PDCLIB_MB_CUR_MAX_DEFINED
#define _PDCLIB_MB_CUR_MAX_DEFINED
#define MB_CUR_MAX (_PDCLIB_mb_cur_max())
#endif

/* Numeric conversion functions */

/* TODO: atof(), strtof(), strtod(), strtold() */

double atof( const char * nptr ) _PDCLIB_nothrow;
double strtod( const char * _PDCLIB_restrict nptr, char * * _PDCLIB_restrict endptr ) _PDCLIB_nothrow;
float strtof( const char * _PDCLIB_restrict nptr, char * * _PDCLIB_restrict endptr ) _PDCLIB_nothrow;
long double strtold( const char * _PDCLIB_restrict nptr, char * * _PDCLIB_restrict endptr ) _PDCLIB_nothrow;

/* Seperate the character array nptr into three parts: A (possibly empty)
   sequence of whitespace characters, a character representation of an integer
   to the given base, and trailing invalid characters (including the terminating
   null character). If base is 0, assume it to be 10, unless the integer
   representation starts with 0x / 0X (setting base to 16) or 0 (setting base to
   8). If given, base can be anything from 0 to 36, using the 26 letters of the
   base alphabet (both lowercase and uppercase) as digits 10 through 35.
   The integer representation is then converted into the return type of the
   function. It can start with a '+' or '-' sign. If the sign is '-', the result
   of the conversion is negated.
   If the conversion is successful, the converted value is returned. If endptr
   is not a NULL pointer, a pointer to the first trailing invalid character is
   returned in *endptr.
   If no conversion could be performed, zero is returned (and nptr in *endptr,
   if endptr is not a NULL pointer). If the converted value does not fit into
   the return type, the functions return LONG_MIN, LONG_MAX, ULONG_MAX,
   LLONG_MIN, LLONG_MAX, or ULLONG_MAX respectively, depending on the sign of
   the integer representation and the return type, and errno is set to ERANGE.
*/
/* There is strtoimax() and strtoumax() in <inttypes.h> operating on intmax_t /
   uintmax_t, if the long long versions do not suit your needs.
*/
long int strtol( const char * _PDCLIB_restrict nptr, char * * _PDCLIB_restrict endptr, int base ) _PDCLIB_nothrow;
long long int strtoll( const char * _PDCLIB_restrict nptr, char * * _PDCLIB_restrict endptr, int base ) _PDCLIB_nothrow;
unsigned long int strtoul( const char * _PDCLIB_restrict nptr, char * * _PDCLIB_restrict endptr, int base ) _PDCLIB_nothrow;
unsigned long long int strtoull( const char * _PDCLIB_restrict nptr, char * * _PDCLIB_restrict endptr, int base ) _PDCLIB_nothrow;

/* These functions are the equivalent of (int)strtol( nptr, NULL, 10 ),
   strtol( nptr, NULL, 10 ) and strtoll(nptr, NULL, 10 ) respectively, with the
   exception that they do not have to handle overflow situations in any defined
   way.
   (PDCLib does not simply forward these to their strtox() equivalents, but
   provides a simpler atox() function that saves a couple of tests and simply
   continues with the conversion in case of overflow.)
*/
int atoi( const char * nptr ) _PDCLIB_nothrow;
long int atol( const char * nptr ) _PDCLIB_nothrow;
long long int atoll( const char * nptr ) _PDCLIB_nothrow;

/* Pseudo-random sequence generation functions */

extern unsigned long int _PDCLIB_seed;

#define RAND_MAX 32767

/* Returns the next number in a pseudo-random sequence, which is between 0 and
   RAND_MAX.
   (PDCLib uses the implementation suggested by the standard document, which is
   next = next * 1103515245 + 12345; return (unsigned int)(next/65536) % 32768;)
*/
int rand( void ) _PDCLIB_nothrow;

/* Initialize a new pseudo-random sequence with the starting seed. Same seeds
   result in the same pseudo-random sequence. The default seed is 1.
*/
void srand( unsigned int seed ) _PDCLIB_nothrow;

/* Memory management functions */

/* Allocate a chunk of memory of given size. If request could not be
   satisfied, return NULL. Otherwise, return a pointer to the allocated
   memory. Memory contents are undefined.
*/
void * malloc( size_t size ) _PDCLIB_nothrow;

/* Allocate a chunk of memory that is large enough to hold nmemb elements of
   the given size, and zero-initialize that memory. If request could not be
   satisfied, return NULL. Otherwise, return a pointer to the allocated
   memory.
*/
void * calloc( size_t nmemb, size_t size ) _PDCLIB_nothrow;

/* Allocate a chunk of memory of given size, with specified alignment (which
   must be a power of two; if it is not, the next greater power of two is
   used). If request could not be satisfied, return NULL. Otherwise, return
   a pointer to the allocated memory.
*/
void * aligned_alloc( size_t alignment, size_t size ) _PDCLIB_nothrow;

/* De-allocate a chunk of heap memory previously allocated using malloc(),
   calloc(), or realloc(), and pointed to by ptr. If ptr does not match a
   pointer previously returned by the mentioned allocation functions, or
   free() has already been called for this ptr, behaviour is undefined.
*/
void free( void * ptr ) _PDCLIB_nothrow;

/* Resize a chunk of memory previously allocated with malloc() and pointed to
   by ptr to the given size (which might be larger or smaller than the original
   size). Returns a pointer to the reallocated memory, or NULL if the request
   could not be satisfied. Note that the resizing might include a memcpy()
   from the original location to a different one, so the return value might or
   might not equal ptr. If size is larger than the original size, the value of
   memory beyond the original size is undefined. If ptr is NULL, realloc()
   behaves like malloc().
*/
void * realloc( void * ptr, size_t size ) _PDCLIB_nothrow;

/* Communication with the environment */

/* These two can be passed to exit() or _Exit() as status values, to signal
   successful and unsuccessful program termination, respectively. EXIT_SUCCESS
   can be replaced by 0. How successful or unsuccessful program termination are
   signaled to the environment, and what happens if exit() or _Exit() are being
   called with a value that is neither of the three, is defined by the hosting
   OS and its glue function.
*/
#define EXIT_SUCCESS _PDCLIB_SUCCESS
#define EXIT_FAILURE _PDCLIB_FAILURE

/* Initiate abnormal process termination, unless programm catches SIGABRT and
   does not return from the signal handler.
   This implementantion flushes all streams, closes all files, and removes any
   temporary files before exiting with EXIT_FAILURE.
   abort() does not return.
*/
_PDCLIB_noreturn void abort( void ) _PDCLIB_nothrow;

/* Register a function that will be called on exit(), or when main() returns.
   At least 32 functions can be registered this way, and will be called in
   reverse order of registration (last-in, first-out).
   Returns zero if registration is successfull, nonzero if it failed.
*/
int atexit( void (*func)( void ) ) _PDCLIB_nothrow;

/* Register a function that will be called on quick_exit(), or when main() returns.
   At least 32 functions can be registered this way, and will be called in
   reverse order of registration (last-in, first-out).
   Returns zero if registration is successfull, nonzero if it failed.
*/
int at_quick_exit( void (*func)( void ) ) _PDCLIB_nothrow;

/* Normal process termination. Functions registered by atexit() (see above) are
   called, streams flushed, files closed and temporary files removed before the
   program is terminated with the given status. (See comment for EXIT_SUCCESS
   and EXIT_FAILURE above.)
   exit() does not return.
*/
_PDCLIB_noreturn void exit( int status ) _PDCLIB_nothrow;

/* Normal process termination. Functions registered by atexit() (see above) are
   NOT CALLED. This implementation DOES flush streams, close files and removes
   temporary files before the program is teminated with the given status. (See
   comment for EXIT_SUCCESS and EXIT_FAILURE above.)
   _Exit() does not return.
*/
_PDCLIB_noreturn void _Exit( int status ) _PDCLIB_nothrow;

/* Quick process termination. Functions registered by at_quick_exit() (see
   above) are called, and the process terminated. No functions registered
   with atexit() (see above) or signal handlers are called.
   quick_exit() does not return.
*/
_PDCLIB_noreturn void quick_exit( int status );

/* Search an environment-provided key-value map for the given key name, and
   return a pointer to the associated value string (or NULL if key name cannot
   be found). The value string pointed to might be overwritten by a subsequent
   call to getenv(). The library never calls getenv() itself.
   Details on the provided keys and how to set / change them are determined by
   the hosting OS and its glue function.
*/
char * getenv( const char * name ) _PDCLIB_nothrow;

/* If string is a NULL pointer, system() returns nonzero if a command processor
   is available, and zero otherwise. If string is not a NULL pointer, it is
   passed to the command processor. If system() returns, it does so with a
   value that is determined by the hosting OS and its glue function.
*/
int system( const char * string ) _PDCLIB_nothrow;

/* Searching and sorting */

/* Do a binary search for a given key in the array with a given base pointer,
   which consists of nmemb elements that are of the given size each. To compare
   the given key with an element from the array, the given function compar is
   called (with key as first parameter and a pointer to the array member as
   second parameter); the function should return a value less than, equal to,
   or greater than 0 if the key is considered to be less than, equal to, or
   greater than the array element, respectively.
   The function returns a pointer to the first matching element found, or NULL
   if no match is found.

   ** May throw **
*/
void * bsearch( const void * key, const void * base, size_t nmemb, size_t size, int (*compar)( const void *, const void * ) );

/* Do a quicksort on an array with a given base pointer, which consists of
   nmemb elements that are of the given size each. To compare two elements from
   the array, the given function compar is called, which should return a value
   less than, equal to, or greater than 0 if the first argument is considered
   to be less than, equal to, or greater than the second argument, respectively.
   If two elements are compared equal, their order in the sorted array is not
   specified.

   ** May throw **
*/
void qsort( void * base, size_t nmemb, size_t size, int (*compar)( const void *, const void * ) );

/* Integer arithmetic functions */

/* Return the absolute value of the argument. Note that on machines using two-
   complement's notation (most modern CPUs), the largest negative value cannot
   be represented as positive value. In this case, behaviour is unspecified.
*/
int abs( int j ) _PDCLIB_nothrow;
long int labs( long int j ) _PDCLIB_nothrow;
long long int llabs( long long int j ) _PDCLIB_nothrow;

/* These structures each have a member quot and a member rem, of type int (for
   div_t), long int (for ldiv_t) and long long it (for lldiv_t) respectively.
   The order of the members is platform-defined to allow the div() functions
   below to be implemented efficiently.
*/
typedef struct _PDCLIB_div_t     div_t;
typedef struct _PDCLIB_ldiv_t   ldiv_t;
typedef struct _PDCLIB_lldiv_t lldiv_t;

/* Return quotient (quot) and remainder (rem) of an integer division in one of
   the structs above.
*/
div_t div( int numer, int denom ) _PDCLIB_nothrow;
ldiv_t ldiv( long int numer, long int denom ) _PDCLIB_nothrow;
lldiv_t lldiv( long long int numer, long long int denom ) _PDCLIB_nothrow;

/* Multibyte / wide character conversion functions */

/* Affected by LC_CTYPE of the current locale. For state-dependent encoding,
   each function is placed into its initial conversion state at program
   startup, and can be returned to that state by a call with its character
   pointer argument s being a null pointer.
   Changing LC_CTYPE causes the conversion state to become indeterminate.
*/

/* If s is not a null pointer, returns the number of bytes contained in the
   multibyte character pointed to by s (if the next n or fewer bytes form a
   valid multibyte character); -1, if they don't; or 0, if s points to the
   null character.
   If s is a null pointer, returns nonzero if multibyte encodings in the
   current locale are stateful, and zero otherwise.
*/
int mblen( const char * s, size_t n );

/* If s is not a null pointer, and the next n bytes (maximum) form a valid
   multibyte character sequence (possibly including shift sequences), the
   corresponding wide character is stored in pwc (unless that is a null
   pointer). If the wide character is the null character, the function is
   left in the initial conversion state.
   Returns the number of bytes in the consumed multibyte character sequence;
   or 0, if the resulting wide character is the null character. If the next
   n bytes do not form a valid sequence, returns -1.
   In no case will the returned value be greater than n or MB_CUR_MAX.
   If s is a null pointer, returns nonzero if multibyte encodings in the
   current locale are stateful, and zero otherwise.
*/
int mbtowc( wchar_t * _PDCLIB_restrict pwc, const char * _PDCLIB_restrict s, size_t n );

/* Converts the wide character wc into the corresponding multibyte character
   sequence (including shift sequences). If s is not a null pointer, the
   multibyte sequence (at most MB_CUR_MAX characters) is stored at that
   location. If wc is a null character, a null byte is stored, preceded by
   any shift sequence needed to restore the initial shift state, and the
   function is left in the initial conversion state.
   Returns the number of bytes in the generated multibyte character sequence.
   If wc does not correspond to a valid multibyte character, returns -1.
   In no case will the returned value be greater than MB_CUR_MAX.
   If s is a null pointer, returns nonzero if multibyte encodings in the
   current locale are stateful, and zero otherwise.
*/
int wctomb( char * s, wchar_t wc );

/* Convert a sequence of multibyte characters beginning in the initial shift
   state from the array pointed to by s into the corresponding wide character
   sequence, storing no more than n wide characters into pwcs. A null
   character is converted into a null wide character, and marks the end of
   the multibyte character sequence.
   If copying takes place between objects that overlap, behaviour is
   undefined.
   Returns (size_t)-1 if an invalid multibyte sequence is encountered.
   Otherwise, returns the number of array elements modified, not including
   a terminating null wide character, if any. (Target string will not be
   null terminated if the return value equals n.)
*/
size_t mbstowcs( wchar_t * _PDCLIB_restrict pwcs, const char * _PDCLIB_restrict s, size_t n );

/* Convert a sequence of wide characters from the array pointed to by pwcs
   into a sequence of corresponding multibyte characters, beginning in the
   initial shift state, storing them in the array pointed to by s, stopping
   if the next multibyte character would exceed the limit of n total bytes
   or a null character is stored.
   If copying takes place between objects that overlap, behaviour is
   undefined.
   Returns (size_t)-1 if a wide character is encountered that does not
   correspond to a valid multibyte character. Otherwise, returns the number
   of array elements modified, not including a terminating null character,
   if any. (Target string will not be null terminated if the return value
   equals n.)
*/
size_t wcstombs( char * _PDCLIB_restrict s, const wchar_t * _PDCLIB_restrict pwcs, size_t n );

#ifdef __cplusplus
}
#endif

#endif