regina/cmath.c

   1 #ifndef lint
   2 static char *RCSid = "$Id$";
   3 #endif
   4
   5 /*
   6  *  The Regina Rexx Interpreter
   7  *  Copyright (C) 1992-1994  Anders Christensen <anders@pvv.unit.no>
   8  *
   9  *  This library is free software; you can redistribute it and/or
  10  *  modify it under the terms of the GNU Library General Public
  11  *  License as published by the Free Software Foundation; either
  12  *  version 2 of the License, or (at your option) any later version.
  13  *
  14  *  This library is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  Library General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU Library General Public
  20  *  License along with this library; if not, write to the Free
  21  *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 /*
  25  * More attention should be paid to overflow and underflow conditions.
  26  * This *is* done in some of the routines for the GCC compiler, but should
  27  * be done in an ANSI-compatible manner.
  28  */
  29
  30
  31 #include "rexx.h"
  32 #include <math.h>
  33 #include <stdio.h>
  34 #include <ctype.h>
  35 #include <string.h>
  36
  37 #ifdef SunKludges
  38 double strtod( const char *, char ** ) ;
  39 #endif
  40
  41 double myatof( const tsd_t *TSD, const streng *string )
  42 {
  43    char *str,*ptr ;
  44    double answer ;
  45
  46    str = str_ofTSD(string) ;
  47    answer = strtod(str,&ptr) ;
  48
  49    /* remove leading spaces */
  50    for (;(*ptr)&&(isspace(*ptr));ptr++) ;
  51 #ifdef SUNOS_STRTOD_BUG
  52    for (;*ptr=='0';ptr++) ;
  53 #endif /* SUNOS_STRTOD_BUG */
  54    if (*ptr)
  55        exiterror( ERR_BAD_ARITHMETIC, 0 )  ;
  56    FreeTSD( str ) ;
  57
  58    return answer ;
  59 }
  60
  61
  62 int myisnumber( const streng *string )
  63 {
  64    const register char *ptr=NULL, *eptr=NULL ;
  65    int num=0 ;
  66
  67    if (!string->len)
  68       return 0 ;
  69
  70    ptr = string->value ;
  71    eptr = Str_end( string ) ;
  72
  73    for (; (ptr<eptr) && (isspace(*ptr)); ptr++) ;
  74    if ((ptr<eptr) && ((*ptr=='-') || (*ptr=='+')))
  75       for (ptr++; (ptr<eptr) && (isspace(*ptr)); ptr++) ;
  76
  77    for (; (ptr<eptr) && isdigit(*ptr); ptr++, num++) ;
  78    if ((ptr<eptr) && *ptr=='.')
  79       for (ptr++;(ptr<eptr) && isdigit(*ptr); ptr++, num++) ;
  80
  81    if (!num)
  82       return 0 ;
  83
  84    if ((ptr<eptr) && ((*ptr=='e') || (*ptr=='E')))
  85    {
  86       ptr++ ;
  87       num = 0 ;
  88       if ((ptr<eptr) && ((*ptr=='-') || (*ptr=='+')))
  89          ptr++ ;
  90
  91       for (; (ptr<eptr) && isdigit(*ptr); ptr++, num++ ) ;
  92       if (!num)
  93          return 0 ;
  94    }
  95
  96    for (; (ptr<eptr) && (isspace(*ptr)); ptr++) ;
  97    return (ptr==eptr) ;
  98 }
  99
 100
 101 /*
 102  * Takes 'string' as parameter, analyze whether it is an integer, and
 103  * return a boolean variable which is true iff 'string' is a legal
 104  * integer. The format of a legal integer is (the regexpr):
 105  *        [ ]*([-+][ ]*)?[0-9]+[ ]*
 106  */
 107 int myisinteger( const streng *string )
 108 {
 109    const char *cptr=NULL, *eptr=NULL ;
 110
 111    cptr = string->value ;
 112    eptr = cptr + string->len ;
 113
 114    for (;cptr<eptr && isspace(*cptr); cptr++) ;
 115    if (cptr<eptr && (*cptr=='-' || *cptr=='+'))
 116       for (cptr++; cptr<eptr && isspace(*cptr); cptr++) ;
 117
 118    if (cptr>=eptr)
 119       return 0 ;
 120
 121    for (;cptr<eptr && isdigit(*cptr); cptr++) ;
 122    for (;cptr<eptr && isspace(*cptr); cptr++) ;
 123    return (cptr==eptr) ;
 124 }