#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include "flonum.h"
#define FALSE (0)
#define TRUE (1)
int
atof_generic (
char **address_of_string_pointer,
const char *string_of_decimal_marks,
const char *string_of_decimal_exponent_marks,
FLONUM_TYPE *address_of_generic_floating_point_number)
{
int return_value;
char * first_digit;
int number_of_digits_before_decimal;
int number_of_digits_after_decimal;
long int decimal_exponent;
int number_of_digits_available;
char digits_sign_char;
{
char * p;
char c;
int seen_significant_digit;
first_digit = * address_of_string_pointer;
c= *first_digit;
if (c=='-' || c=='+')
{
digits_sign_char = c;
first_digit ++;
}
else
digits_sign_char = '+';
if( (first_digit[0]=='n' || first_digit[0]=='N')
&& (first_digit[1]=='a' || first_digit[1]=='A')
&& (first_digit[2]=='n' || first_digit[2]=='N')) {
address_of_generic_floating_point_number->sign=0;
address_of_generic_floating_point_number->exponent=0;
address_of_generic_floating_point_number->leader=address_of_generic_floating_point_number->low;
(*address_of_string_pointer)=first_digit+3;
return 0;
}
if( (first_digit[0]=='i' || first_digit[0]=='I')
&& (first_digit[1]=='n' || first_digit[1]=='N')
&& (first_digit[2]=='f' || first_digit[2]=='F')) {
address_of_generic_floating_point_number->sign= digits_sign_char=='+' ? 'P' : 'N';
address_of_generic_floating_point_number->exponent=0;
address_of_generic_floating_point_number->leader=address_of_generic_floating_point_number->low;
if( (first_digit[3]=='i' || first_digit[3]=='I')
&& (first_digit[4]=='n' || first_digit[4]=='N')
&& (first_digit[5]=='i' || first_digit[5]=='I')
&& (first_digit[6]=='t' || first_digit[6]=='T')
&& (first_digit[7]=='y' || first_digit[7]=='Y'))
(*address_of_string_pointer)=first_digit+8;
else
(*address_of_string_pointer)=first_digit+3;
return 0;
}
number_of_digits_before_decimal = 0;
number_of_digits_after_decimal = 0;
decimal_exponent = 0;
seen_significant_digit = FALSE;
for (p = first_digit;
(c = * p)
&& (!c || ! strchr(string_of_decimal_marks, c) )
&& (!c || ! strchr(string_of_decimal_exponent_marks, c) );
p ++)
{
if (isdigit(c))
{
if (seen_significant_digit || c > '0')
{
number_of_digits_before_decimal ++;
seen_significant_digit = TRUE;
}
else
{
first_digit++;
}
}
else
{
break;
}
}
if (c && strchr(string_of_decimal_marks, c))
{
for (p ++;
(c = * p)
&& (!c || ! strchr(string_of_decimal_exponent_marks, c) );
p ++)
{
if (isdigit(c))
{
number_of_digits_after_decimal ++;
if ( c > '0')
{
seen_significant_digit = TRUE;
}
}
else
{
if ( ! seen_significant_digit)
{
number_of_digits_after_decimal = 0;
}
break;
}
}
}
while(number_of_digits_after_decimal && first_digit[number_of_digits_before_decimal+number_of_digits_after_decimal]=='0')
--number_of_digits_after_decimal;
if (c && strchr(string_of_decimal_exponent_marks, c) )
{
char digits_exponent_sign_char;
c = * ++ p;
if (c && strchr("+-",c))
{
digits_exponent_sign_char = c;
c = * ++ p;
}
else
{
digits_exponent_sign_char = '+';
}
for (;
(c);
c = * ++ p)
{
if (isdigit(c))
{
decimal_exponent = decimal_exponent * 10 + c - '0';
}
else
{
break;
}
}
if (digits_exponent_sign_char == '-')
{
decimal_exponent = - decimal_exponent;
}
}
* address_of_string_pointer = p;
}
number_of_digits_available =
number_of_digits_before_decimal
+ number_of_digits_after_decimal;
return_value = 0;
if (number_of_digits_available == 0)
{
address_of_generic_floating_point_number -> exponent = 0;
address_of_generic_floating_point_number -> leader
= -1 + address_of_generic_floating_point_number -> low;
address_of_generic_floating_point_number -> sign = digits_sign_char;
}
else
{
LITTLENUM_TYPE * digits_binary_low;
int precision;
int maximum_useful_digits;
int number_of_digits_to_use;
int more_than_enough_bits_for_digits;
int more_than_enough_littlenums_for_digits;
int size_of_digits_in_littlenums;
int size_of_digits_in_chars;
FLONUM_TYPE power_of_10_flonum;
FLONUM_TYPE digits_flonum;
precision = (address_of_generic_floating_point_number -> high
- address_of_generic_floating_point_number -> low
+ 1
);
maximum_useful_digits = ( ((double) (precision - 2))
* ((double) (LITTLENUM_NUMBER_OF_BITS))
/ (LOG_TO_BASE_2_OF_10)
)
+ 2;
if (number_of_digits_available > maximum_useful_digits)
{
number_of_digits_to_use = maximum_useful_digits;
}
else
{
number_of_digits_to_use = number_of_digits_available;
}
decimal_exponent += number_of_digits_before_decimal - number_of_digits_to_use;
more_than_enough_bits_for_digits
= ((((double)number_of_digits_to_use) * LOG_TO_BASE_2_OF_10) + 1);
more_than_enough_littlenums_for_digits
= ( more_than_enough_bits_for_digits
/ LITTLENUM_NUMBER_OF_BITS
)
+ 2;
size_of_digits_in_littlenums = more_than_enough_littlenums_for_digits;
size_of_digits_in_chars = size_of_digits_in_littlenums
* sizeof( LITTLENUM_TYPE );
digits_binary_low = (LITTLENUM_TYPE *)
alloca (size_of_digits_in_chars);
memset((char *)digits_binary_low, '\0', size_of_digits_in_chars);
{
char * p;
char c;
int count;
for (p = first_digit, count = number_of_digits_to_use;
count;
p ++, -- count)
{
c = * p;
if (isdigit(c))
{
long int carry;
LITTLENUM_TYPE * littlenum_pointer;
LITTLENUM_TYPE * littlenum_limit;
littlenum_limit
= digits_binary_low
+ more_than_enough_littlenums_for_digits
- 1;
carry = c - '0';
for (littlenum_pointer = digits_binary_low;
littlenum_pointer <= littlenum_limit;
littlenum_pointer ++)
{
long int work;
work = carry + 10 * (long)(*littlenum_pointer);
* littlenum_pointer = work & LITTLENUM_MASK;
carry = work >> LITTLENUM_NUMBER_OF_BITS;
}
if (carry != 0)
{
abort();
}
}
else
{
++ count;
}
}
}
while (digits_binary_low [size_of_digits_in_littlenums - 1] == 0
&& size_of_digits_in_littlenums >= 2)
size_of_digits_in_littlenums --;
digits_flonum . low = digits_binary_low;
digits_flonum . high = digits_binary_low + size_of_digits_in_littlenums - 1;
digits_flonum . leader = digits_flonum . high;
digits_flonum . exponent = 0;
digits_flonum . sign = '+';
{
LITTLENUM_TYPE *power_binary_low;
int decimal_exponent_is_negative;
FLONUM_TYPE temporary_flonum;
LITTLENUM_TYPE *temporary_binary_low;
int size_of_power_in_littlenums;
int size_of_power_in_chars;
size_of_power_in_littlenums = precision;
decimal_exponent_is_negative = decimal_exponent < 0;
if (decimal_exponent_is_negative)
{
decimal_exponent = - decimal_exponent;
}
size_of_power_in_chars
= size_of_power_in_littlenums
* sizeof( LITTLENUM_TYPE ) + 2;
power_binary_low = (LITTLENUM_TYPE *) alloca ( size_of_power_in_chars );
temporary_binary_low = (LITTLENUM_TYPE *) alloca ( size_of_power_in_chars );
memset((char *)power_binary_low, '\0', size_of_power_in_chars);
* power_binary_low = 1;
power_of_10_flonum . exponent = 0;
power_of_10_flonum . low = power_binary_low;
power_of_10_flonum . leader = power_binary_low;
power_of_10_flonum . high = power_binary_low + size_of_power_in_littlenums - 1;
power_of_10_flonum . sign = '+';
temporary_flonum . low = temporary_binary_low;
temporary_flonum . high = temporary_binary_low + size_of_power_in_littlenums - 1;
{
int place_number_limit;
int place_number;
const const_FLONUM_TYPE * multiplicand;
place_number_limit = table_size_of_flonum_powers_of_ten;
multiplicand
= ( decimal_exponent_is_negative
? flonum_negative_powers_of_ten
: flonum_positive_powers_of_ten);
for (place_number = 1;
decimal_exponent;
decimal_exponent >>= 1
, place_number ++)
{
if (decimal_exponent & 1)
{
if (place_number > place_number_limit)
{
return_value = ERROR_EXPONENT_OVERFLOW;
decimal_exponent = 0;
}
else
{
#ifdef TRACE
printf("before multiply, place_number = %d., power_of_10_flonum:\n", place_number);
flonum_print( & power_of_10_flonum );
(void)putchar('\n');
#endif
flonum_multip ((const_FLONUM_TYPE *)multiplicand + place_number, & power_of_10_flonum, & temporary_flonum);
flonum_copy (& temporary_flonum, & power_of_10_flonum);
}
}
}
#ifdef TRACE
printf( " after computing power_of_10_flonum: " );
flonum_print( & power_of_10_flonum );
(void)putchar('\n');
#endif
}
}
flonum_multip ((const_FLONUM_TYPE *)&power_of_10_flonum, & digits_flonum, address_of_generic_floating_point_number);
address_of_generic_floating_point_number -> sign = digits_sign_char;
}
return (return_value);
}