regina/cmath.c

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