#ifndef js_H
#define js_H

/* J. Stolfi's miscellaneous general-purpose definitions */
/* Last edited on 2005-01-16 15:01:00 by stolfi */
/* Copyright © 2005 Jorge Stolfi, UNICAMP. See note at end of file. */

#include <stdio.h>
#include <sys/time.h>
#include <time.h>

/* HANDY BASIC TYPES */

#ifndef HAVE_BOOL
typedef enum {FALSE = 0, TRUE = 1} bool;
#define FALSE FALSE
#define TRUE TRUE
#define HAVE_BOOL 1
#endif

typedef unsigned int nat;

typedef void * MemP;  /* Pointer to memory area */
typedef int MemSize;  /* Size in bytes of memory area */

typedef int int_cmp_t(int a, int b); 
  /* A signed comparison predicate for integers (indices, etc.). */

/* ERRORS AND ASSERTIONS */

void fatalerror (const char *msg);
  /* Prints string {*msg} to {stderr} and stops. */

void programerror (const char *msg, const char *file, unsigned int line, const char* proc);
  /* Prints {file ":" line ": (" *proc ")" *msg} to {stderr} and stops.
    Meant for {affirm} below. */

#define affirm(test, msg) \
  do \
    { if (!(test)) (void)programerror((msg), __FILE__, __LINE__, __FUNCTION__); } \
  while (0)
  /* Like the standard {assert}, but with an error message. If test is
    false, aborts after printing {*msg} and the source location. It is
    declared as a macro, rather than as a procedure, in order to avoid
    evaluating {msg} when {test} is true.  */

#define demand affirm
  /* Same as {affirm}, but intended to check the validity of
    client/user data (rather than paranoia checks). */

void *checknotnull(const void *p, const char *msg, const char *file, unsigned int line, const char* proc);
  /* If {p == NULL}, prints {file ":" line ": (" *proc ")" *msg} to {stderr} and
    stops; otherwise returns {p} itself.  Meant for {notnull} below. */

#define notnull(p, msg) \
  checknotnull(p, (msg), __FILE__, __LINE__, __FUNCTION__)
  /* If {p == NULL}, aborts with {*msg} with the program 
    location; otherwise returns {p} itself. */
  
/* STRING UTILITIES */

int isprefix(const char *s, const char *t);
  /* Returns TRUE iff the string {*s} is a prefix of {*t},
    including the cases when {*s} is empty or is equal to {*t}. */

char *txtcat (const char *a, const char *b);
  /* Returns a string that is the concatenation of {*a} and {*b}. 
    The result is always a newly allocated string. */
  
char *txtcat3 (const char *a, const char *b, const char *c);
  /* Returns a string that is the concatenation of {*a,*b,*c}. 
    The result is always a newly allocated string. */
  
char *addext(const char *name, const char *ext);
  /* Appends the string {*ext} (which should normally start with a
    period) to the given file {*name}. However, if {*name} is empty or
    "-", ignores {*ext} and returns a copy of {*name} itself. In any
    case, the result is a newly allocated string.*/

char *fmtint(int x, unsigned wid);
  /* Returns a newly allocated string containing the integer {x}
    converted to decimal and zero-padded to {wid} characters. */

/* TIME/DATE UNTILITIES */

char *today(void);
  /* Returns a newly allocated string containing 
    today's date in the format "yy-mm-dd hh:mm:ss" */

double now(void);
  /* Returns the current user time of the process, in microseconds. */

/* FILE AND I/O UTILITIES */

FILE *open_write(const char *name);
FILE *open_read(const char *name);
  /* Opens file for output or input, bombs in case of failure. */
    
char *read_line(FILE *f);
  /* Reads the next line from file {f}, until '\n', NUL, or EOF.
    Returns it as a NUL-terminated string, without the final '\n'.
    Replaces TABs by single spaces. Allocates space for the result with 
    {malloc()}. Returns NULL iff the file is already at EOF. */
  
/* MATH UTILITIES */

#if (defined(SunOS4) || defined(SunOS5))
extern long random(void);
extern int srandom(unsigned seed);
#endif

float frandom(void);
double drandom(void);
  /* Returns a uniform random number in [0.0 __ 1.0). */

float fgaussrand(void);
double dgaussrand(void);
  /* Returns a random number with Gaussian distr, zero mean, 
    unit deviation. */

int ipow(int x, nat y);
  /* Returns {x^y}. */

double rel_diff(double x, double y);
  /* Returns the relative difference between {x} and {y}, namely
    {(x-y)/sqrt(x^2 + y^2)/2}. This number is zero when {x == y}, is
    0.5 when only one of them is zero, and has extremal values -1
    and +1 when {x} and {y} are equal and opposite). */
    
#endif
/* COPYRIGHT AND AUTHORSHIP NOTICE

  Copyright © 2005 Jorge Stolfi, Universidade Estadual de Campinas (UNICAMP).
  Created by Jorge Stolfi in 1992--2005.
  
  This source file can be freely distributed, used, and modified,
  provided that this copyright and authorship notice is preserved in
  all copies, and that any modified versions of this file are clearly
  marked as such.
  
  This software has NO WARRANTY of correctness or applicability for
  any purpose. Neither the author nor his employers shall be held
  responsible for any losses or damages that may result from its use.

  END OF NOTICE */