source: git/ntl/doc/tools.txt @ 26e030

/**************************************************************************\

MODULE: tools

SUMMARY:

Some useful tools that are used throughout NTL.

\**************************************************************************/

#include <cstdlib>
#include <cmath>
#include <iostream>

#include <NTL/config.h>
#include <NTL/mach_desc.h>




double GetTime();
// returns number of seconds of CPU time used by this process;

void PrintTime(ostream& s, double t);
// prints the time t (in seconds) to s in the format
//     ss  or  mm:ss  or  hh:mm:ss,
// where the value t is first rounded to the nearest integer.

void Error(const char *s);
// print an error message and call abort

extern void (*ErrorCallback)();
// A pointer (initially NULL) to a callback function.
// This function will be called by the Error function,
// as well as other functions, before calling abort().
// Note that the callback function is expected to have
// C++ linkage, as it is called directly by a C++ function,
// even though the latter function may be called from a
// C function.

long IsWhiteSpace(long c);
// returns 1 if c is "wite space" (as defined by isspace is the
// standard library...usually blanks, tabs, newlines), and 0 otherwise.

long SkipWhiteSpace(istream& s);
// skips white space (as defined by IsWhiteSpace).
// Return value is 0 if end-of-file is reached; otherwise,
// return value is 1.

// This routine is useful in conjuction with input routines,
// like NTL's, that raise an error if an input item is
// ill-formed or missing.  

long IsEOFChar(long c);
// test if c == EOF


long CharToIntVal(long c);
// returns the hexidecimal value of c if c is '0'..'9', 'A'..'F', or 'a'..'f';
// otherwise, the return value is -1.

char IntValToChar(long x);
// returns the hexadecimal digit '0'..'9', 'a'..'f' representing x;
// an error is raised if x < 0 or x > 15.

long IsFinite(double *p);
// Returns 1 if *p is a "finite" floating point number.
// A pointer is used to ensure that the number is in memory,
// which on some architectures (notably x86/Pentium) can make a difference.

// some min/max and swap routines:

int min(int a, int b);
int max(int a, int b);

long min(long a, long b);
long max(long a, long b);

long min(int a, long b);
long max(int a, long b);

long min(long a, int b);
long max(long a, int b);

void swap(long& a, long& b);
void swap(int& a, int& b);


// defined here are all the conversion routines among the types 
// int, long, float, double.  See conversions.txt for complete details.


// The following platform-dependent macros are defined:

#define NTL_BITS_PER_LONG      (...)  /* bits in a long */
#define NTL_MAX_LONG           (...)  /* max value of a long */
#define NTL_MIN_LONG           (...)  /* min value of a long */

#define NTL_BITS_PER_INT       (...)  /* bits in a int */
#define NTL_MAX_INT            (...)  /* max value of a int */
#define NTL_MIN_INT            (...)  /* min value of a int */

#define NTL_DOUBLE_PRECISION   (...)  /* # of bits of precision in a double */
#define NTL_FDOUBLE_PRECISION  (...)  /* the double value 
                                        2^{NTL_DOUBLE_PRECISION-1} */

#define NTL_ARITH_RIGHT_SHIFT  (...)  /* 1 if signed right-shift is
                                        arithmetic; 0 otherwise */

#define NTL_EXT_DOUBLE         (...)  /* 1 if platform has "extended" doubles;
                                        0 otherwise */