banan-os/BAN/include/BAN/Formatter.h

250 lines
6.0 KiB
C++

#pragma once
#include <BAN/Move.h>
#include <stdint.h>
#include <stddef.h>
namespace BAN::Formatter
{
struct ValueFormat;
template<typename F>
static void print(F putc, const char* format);
template<typename F, typename Arg, typename... Args>
static void print(F putc, const char* format, Arg&& arg, Args&&... args);
template<typename F, typename... Args>
static void println(F putc, const char* format, Args&&... args);
template<typename F, typename T>
static void print_argument(F putc, T value, const ValueFormat& format);
namespace detail
{
template<typename F, typename T>
static size_t parse_format_and_print_argument(F putc, const char* format, T&& arg);
}
/*
IMPLEMENTATION
*/
struct ValueFormat
{
int base = 10;
int percision = 3;
int fill = 0;
bool upper = false;
};
template<typename F>
void print(F putc, const char* format)
{
while (*format)
{
putc(*format);
format++;
}
}
template<typename F, typename Arg, typename... Args>
void print(F putc, const char* format, Arg&& arg, Args&&... args)
{
while (*format && *format != '{')
{
putc(*format);
format++;
}
if (*format == '{')
{
size_t arg_len = detail::parse_format_and_print_argument(putc, format, forward<Arg>(arg));
if (arg_len == size_t(-1))
return print(putc, format);
print(putc, format + arg_len, forward<Args>(args)...);
}
}
template<typename F, typename... Args>
void println(F putc, const char* format, Args&&... args)
{
print(putc, format, args...);
putc('\n');
}
namespace detail
{
template<typename F, typename Arg>
size_t parse_format_and_print_argument(F putc, const char* format, Arg&& argument)
{
ValueFormat value_format;
if (format[0] != '{')
return size_t(-1);
size_t i = 1;
do
{
if (!format[i] || format[i] == '}')
break;
if ('0' <= format[i] && format[i] <= '9')
{
int fill = 0;
while ('0' <= format[i] && format[i] <= '9')
{
fill = (fill * 10) + (format[i] - '0');
i++;
}
value_format.fill = fill;
}
switch (format[i])
{
case 'b': value_format.base = 2; value_format.upper = false; i++; break;
case 'B': value_format.base = 2; value_format.upper = true; i++; break;
case 'o': value_format.base = 8; value_format.upper = false; i++; break;
case 'O': value_format.base = 8; value_format.upper = true; i++; break;
case 'd': value_format.base = 10; value_format.upper = false; i++; break;
case 'D': value_format.base = 10; value_format.upper = true; i++; break;
case 'h': value_format.base = 16; value_format.upper = false; i++; break;
case 'H': value_format.base = 16; value_format.upper = true; i++; break;
default: break;
}
if (!format[i] || format[i] == '}')
break;
if (format[i] == '.')
{
i++;
int percision = 0;
while ('0' <= format[i] && format[i] <= '9')
{
percision = (percision * 10) + (format[i] - '0');
i++;
}
value_format.percision = percision;
}
} while(false);
if (format[i] != '}')
return size_t(-1);
print_argument(putc, forward<Arg>(argument), value_format);
return i + 1;
}
static char value_to_base_char(uint8_t value, int base, bool upper)
{
if (base <= 10)
return value + '0';
if (base <= 36)
{
if (value < 10)
return value + '0';
return value + (upper ? 'A' : 'a') - 10;
}
return '?';
}
template<typename F, typename T>
void print_integer(F putc, T value, const ValueFormat& format)
{
if (value == 0)
{
for (int i = 0; i < format.fill || i < 1; i++)
putc('0');
return;
}
bool sign = false;
// Fits signed 64-bit binary number and null
char buffer[66];
char* ptr = buffer + sizeof(buffer);
*(--ptr) = '\0';
if (value < 0)
{
sign = true;
T digit = (format.base - (value % format.base)) % format.base;
*(--ptr) = value_to_base_char(digit, format.base, format.upper);
value = -(value / format.base);
}
while (value)
{
*(--ptr) = value_to_base_char(value % format.base, format.base, format.upper);
value /= format.base;
}
while (ptr >= buffer + sizeof(buffer) - format.fill)
*(--ptr) = '0';
if (sign)
*(--ptr) = '-';
print(putc, ptr);
}
template<typename F, typename T>
void print_floating(F putc, T value, const ValueFormat& format)
{
int64_t int_part = (int64_t)value;
T frac_part = value - (T)int_part;
if (frac_part < 0)
frac_part = -frac_part;
print_integer(putc, int_part, format);
if (format.percision > 0)
putc('.');
for (int i = 0; i < format.percision; i++)
{
frac_part *= format.base;
if (i == format.percision - 1)
frac_part += 0.5;
putc(value_to_base_char((uint8_t)frac_part % format.base, format.base, format.upper));
}
}
template<typename F>
void print_pointer(F putc, void* ptr, const ValueFormat& format)
{
uintptr_t value = (uintptr_t)ptr;
print(putc, "0x");
for (int i = sizeof(void*) * 8 - 4; i >= 0; i -= 4)
putc(value_to_base_char((value >> i) & 0xF, 16, format.upper));
}
}
/*
TEMPLATE SPECIALIZATIONS
*/
template<typename F, integral T> void print_argument(F putc, T value, const ValueFormat& format) { detail::print_integer(putc, value, format); }
template<typename F, floating_point T> void print_argument(F putc, T value, const ValueFormat& format) { detail::print_floating(putc, value, format); }
template<typename F, pointer T> void print_argument(F putc, T value, const ValueFormat& format) { detail::print_pointer(putc, (void*)value, format); }
template<typename F> void print_argument(F putc, char value, const ValueFormat&) { putc(value); }
template<typename F> void print_argument(F putc, bool value, const ValueFormat&) { print(putc, value ? "true" : "false"); }
template<typename F> void print_argument(F putc, const char* value, const ValueFormat&) { print(putc, value); }
template<typename F> void print_argument(F putc, char* value, const ValueFormat&) { print(putc, value); }
}