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#pragma once
#include <vector>
#include <cybozu/itoa.hpp>
#include <cybozu/atoi.hpp>
#include <mcl/unit.hpp>
/**
@file
@brief utility of Fp
@author MITSUNARI Shigeo(@herumi)
@license modified new BSD license
http://opensource.org/licenses/BSD-3-Clause
*/
namespace mcl { namespace fp {
/*
convert x[0..n) to hex string
start "0x" if withPrefix
*/
template<class T>
void toStr16(std::string& str, const T *x, size_t n, bool withPrefix = false)
{
size_t fullN = 0;
if (n > 1) {
size_t pos = n - 1;
while (pos > 0) {
if (x[pos]) break;
pos--;
}
if (pos > 0) fullN = pos;
}
const T v = n == 0 ? 0 : x[fullN];
const size_t topLen = cybozu::getHexLength(v);
const size_t startPos = withPrefix ? 2 : 0;
const size_t lenT = sizeof(T) * 2;
str.resize(startPos + fullN * lenT + topLen);
if (withPrefix) {
str[0] = '0';
str[1] = 'x';
}
cybozu::itohex(&str[startPos], topLen, v, false);
for (size_t i = 0; i < fullN; i++) {
cybozu::itohex(&str[startPos + topLen + i * lenT], lenT, x[fullN - 1 - i], false);
}
}
/*
convert x[0..n) to bin string
start "0b" if withPrefix
*/
template<class T>
void toStr2(std::string& str, const T *x, size_t n, bool withPrefix)
{
size_t fullN = 0;
if (n > 1) {
size_t pos = n - 1;
while (pos > 0) {
if (x[pos]) break;
pos--;
}
if (pos > 0) fullN = pos;
}
const T v = n == 0 ? 0 : x[fullN];
const size_t topLen = cybozu::getBinLength(v);
const size_t startPos = withPrefix ? 2 : 0;
const size_t lenT = sizeof(T) * 8;
str.resize(startPos + fullN * lenT + topLen);
if (withPrefix) {
str[0] = '0';
str[1] = 'b';
}
cybozu::itobin(&str[startPos], topLen, v);
for (size_t i = 0; i < fullN; i++) {
cybozu::itobin(&str[startPos + topLen + i * lenT], lenT, x[fullN - 1 - i]);
}
}
/*
convert hex string to x[0..xn)
hex string = [0-9a-fA-F]+
*/
template<class T>
void fromStr16(T *x, size_t xn, const char *str, size_t strLen)
{
if (strLen == 0) throw cybozu::Exception("fp:fromStr16:strLen is zero");
const size_t unitLen = sizeof(T) * 2;
const size_t q = strLen / unitLen;
const size_t r = strLen % unitLen;
const size_t requireSize = q + (r ? 1 : 0);
if (xn < requireSize) throw cybozu::Exception("fp:fromStr16:short size") << xn << requireSize;
for (size_t i = 0; i < q; i++) {
bool b;
x[i] = cybozu::hextoi(&b, &str[r + (q - 1 - i) * unitLen], unitLen);
if (!b) throw cybozu::Exception("fp:fromStr16:bad char") << cybozu::exception::makeString(str, strLen);
}
if (r) {
bool b;
x[q] = cybozu::hextoi(&b, str, r);
if (!b) throw cybozu::Exception("fp:fromStr16:bad char") << cybozu::exception::makeString(str, strLen);
}
for (size_t i = requireSize; i < xn; i++) x[i] = 0;
}
} } // mcl::fp
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