printf/printfDecimal.c

#include <string.h>
#include <math.h>
#include "ft_printf_internal.h"

char getDecimalCount(struct printf_format_params* format, long double* number, char alphabetLen)
{
    int result = 7;
    int i;
    int sign = signbit(*number) ? -1 : 1;
    int nextDecimal;

    if (format->precision >=0)
        return format->precision +1;
    *number *= sign;
    i = 0;
    while (i <= result)
    {
        *number = *number * alphabetLen;
        ++i;
    }
    nextDecimal = (int) ((*number - (long long) *number) * alphabetLen);
    *number = (long long) *number;
    if (nextDecimal >= alphabetLen/2)
        (*number)++;
    while (i)
    {
        *number = *number / alphabetLen;
        --i;
    }
    *number *= sign;
    return result;
}

int printfDecimalSpecial(struct printf_data* data, char isNegative, const char* str)
{
    int sign = 0;
    int sysCallRet;

    if (isNegative)
        sign = printfWrite(data, "-", 1);
    if (sign < 0)
        return sign;
    sysCallRet = printfWrite(data, str, 3);
    if (sysCallRet < 0)
        return sysCallRet;
    return sysCallRet + sign;

}

int printDecimals(struct printf_data* data, char decimalToPrint, long double number, const char* alphabet)
{
    int sysCallRet;
    int result;
    int alphabetLen = strlen(alphabet);

    if (decimalToPrint < 0)
        return 0;
    if (number < 0)
        number *= -1;
    sysCallRet = printfWrite(data, ".", 1);
    if (sysCallRet < 0)
        return sysCallRet;
    result = sysCallRet;
    decimalToPrint--;
    while (decimalToPrint)
    {
        number = (number - (int) number) * alphabetLen;
        sysCallRet = printfWrite(data, &alphabet[(int)number], 1);
        if (sysCallRet < 0)
            return sysCallRet;
        result += sysCallRet;
        decimalToPrint--;
    }
    return result;
}

int doPrintfF(struct printf_data* data, struct printf_format_params* format, long double number, const char* alphabet)
{
    int result;
    int decimalToPrint = getDecimalCount(format, &number, strlen(alphabet));
    int sysCallRet;

    result = printfNumber(data, format, (long long) number, decimalToPrint, alphabet);
    if (result < 0)
        return result;
    sysCallRet = printDecimals(data, decimalToPrint, number, alphabet);
    if (sysCallRet < 0)
        return sysCallRet;
    result += sysCallRet;
    if ((format->flags & PRINTF_FLAG_LEFT_PADDING) && !(format->flags & PRINTF_FLAG_ZERO_PAD))
    {
        sysCallRet = pad(data, format, result);
        if (sysCallRet < 0)
            return sysCallRet;
        result += sysCallRet;
    }
    return result;
}

int printf_f(struct printf_data* data, struct printf_format_params* format, va_list args)
{
    double number = va_arg(args, double);
    if (isnan(number))
        return printfDecimalSpecial(data, signbit(number), "nan");
    if (!isfinite(number))
        return printfDecimalSpecial(data, signbit(number), "inf");
    return doPrintfF(data, format, number, DEC_ALPHABET);
}

int printf_F(struct printf_data* data, struct printf_format_params* format, va_list args)
{
    double number = va_arg(args, double);
    if (isnan(number))
        return printfDecimalSpecial(data, signbit(number), "NAN");
    if (!isfinite(number))
        return printfDecimalSpecial(data, signbit(number), "INF");
    return doPrintfF(data, format, number, DEC_ALPHABET);
}

int printf_a(struct printf_data* data, struct printf_format_params* format, va_list args)
{
    double number = va_arg(args, double);
    if (isnan(number))
        return printfDecimalSpecial(data, signbit(number), "nan");
    if (!isfinite(number))
        return printfDecimalSpecial(data, signbit(number), "inf");
    format->flags |= PRINTF_FLAG_ALTERNATE_FORM;
    format->typeName = printf_x;
    return doPrintfF(data, format, number, HEx_ALPHABET);
}

int printf_A(struct printf_data* data, struct printf_format_params* format, va_list args)
{
    double number = va_arg(args, double);
    if (isnan(number))
        return printfDecimalSpecial(data, signbit(number), "NAN");
    if (!isfinite(number))
        return printfDecimalSpecial(data, signbit(number), "INF");
    format->flags |= PRINTF_FLAG_ALTERNATE_FORM;
    format->typeName = printf_X;
    return doPrintfF(data, format, number, HEX_ALPHABET);
}