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Merged
chaoticgd merged 2 commits into from
Aug 13, 2025
Merged

Rewrite 128 bit integer string functions #276

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bc189d1
Deduplicate 128 bit integer to_string/from_string functions
chaoticgd Aug 13, 2025
951f574
Rewrite u128::from_string to be more permissive
chaoticgd Aug 13, 2025
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91 changes: 39 additions & 52 deletions src/ccc/int128.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -132,33 +132,48 @@ std::string u128::to_string()
return result;
}

std::optional<u128> u128::from_string(const std::string&& hex)
std::optional<u128> u128::from_string(const std::string& hex)
{
size_t end_of_number = hex.size();
for (size_t i = 0; i < hex.size(); i++) {
if ((hex[i] < '0' || hex[i] > '9') && (hex[i] < 'A' || hex[i] > 'F') && (hex[i] < 'a' || hex[i] > 'f')) {
end_of_number = i;
break;
}
}

if (end_of_number == 0) {
return std::nullopt;
}

u128 result;
for (u32 i = 0; i < 16; i++) {
char c = hex[i];

for (size_t i = 0; i < std::min(end_of_number, static_cast<size_t>(16)); i++) {
char c = hex[end_of_number - i - 1];
if (c >= '0' && c <= '9') {
result.high |= static_cast<u64>(c - '0') << ((15 - i) * 4);
result.low |= static_cast<u64>(c - '0') << (i * 4);
} else if (c >= 'A' && c <= 'F') {
result.high |= static_cast<u64>(10 + c - 'A') << ((15 - i) * 4);
result.low |= static_cast<u64>(10 + c - 'A') << (i * 4);
} else if (c >= 'a' && c <= 'f') {
result.high |= static_cast<u64>(10 + c - 'a') << ((15 - i) * 4);
} else {
return std::nullopt;
}
result.low |= static_cast<u64>(10 + c - 'a') << (i * 4);
}
}
for (u32 i = 0; i < 16; i++) {
char c = hex[16 + i];

if (end_of_number <= 16) {
return result;
}

for (size_t i = 0; i < std::min(end_of_number - 16, static_cast<size_t>(16)); i++) {
char c = hex[end_of_number - i - 17];
if (c >= '0' && c <= '9') {
result.low |= static_cast<u64>(c - '0') << ((15 - i) * 4);
result.high |= static_cast<u64>(c - '0') << (i * 4);
} else if (c >= 'A' && c <= 'F') {
result.low |= static_cast<u64>(10 + c - 'A') << ((15 - i) * 4);
result.high |= static_cast<u64>(10 + c - 'A') << (i * 4);
} else if (c >= 'a' && c <= 'f') {
result.low |= static_cast<u64>(10 + c - 'a') << ((15 - i) * 4);
} else {
return std::nullopt;
}
result.high |= static_cast<u64>(10 + c - 'a') << (i * 4);
}
}

return result;
}

Expand Down Expand Up @@ -283,44 +298,16 @@ s128 s128::operator>>(u64 bits)

std::string s128::to_string()
{
std::string result(32, '\0');
for (u32 i = 0; i < 16; i++) {
result[i] = HEX_DIGITS[(high >> ((15 - i) * 4)) & 0xf];
}
for (u32 i = 0; i < 16; i++) {
result[16 + i] = HEX_DIGITS[(low >> ((15 - i) * 4)) & 0xf];
}
return result;
return u128(*this).to_string();
}

std::optional<s128> s128::from_string(const std::string&& hex)
std::optional<s128> s128::from_string(const std::string& hex)
{
s128 result;
for (u32 i = 0; i < 16; i++) {
char c = hex[i];
if (c >= '0' && c <= '9') {
result.high |= static_cast<u64>(c - '0') << ((15 - i) * 4);
} else if (c >= 'A' && c <= 'F') {
result.high |= static_cast<u64>(10 + c - 'A') << ((15 - i) * 4);
} else if (c >= 'a' && c <= 'f') {
result.high |= static_cast<u64>(10 + c - 'a') << ((15 - i) * 4);
} else {
return std::nullopt;
}
}
for (u32 i = 0; i < 16; i++) {
char c = hex[16 + i];
if (c >= '0' && c <= '9') {
result.low |= static_cast<u64>(c - '0') << ((15 - i) * 4);
} else if (c >= 'A' && c <= 'F') {
result.low |= static_cast<u64>(10 + c - 'A') << ((15 - i) * 4);
} else if (c >= 'a' && c <= 'f') {
result.low |= static_cast<u64>(10 + c - 'a') << ((15 - i) * 4);
} else {
return std::nullopt;
}
}
return result;
std::optional<u128> value = u128::from_string(hex);
if (!value.has_value())
return std::nullopt;

return s128(*value);
}

}
4 changes: 2 additions & 2 deletions src/ccc/int128.h
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Original file line number Diff line number Diff line change
Expand Up @@ -38,7 +38,7 @@ struct u128 {
friend bool operator!=(const u128& lhs, const u128& rhs) = default;

std::string to_string();
static std::optional<u128> from_string(const std::string&& hex);
static std::optional<u128> from_string(const std::string& hex);
};

struct s128 {
Expand Down Expand Up @@ -69,7 +69,7 @@ struct s128 {
friend bool operator!=(const s128& lhs, const s128& rhs) = default;

std::string to_string();
static std::optional<s128> from_string(const std::string&& hex);
static std::optional<s128> from_string(const std::string& hex);
};

}
32 changes: 24 additions & 8 deletions test/ccc/int128_tests.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -97,10 +97,18 @@ TEST(CCCInt128, UnsignedToString)

TEST(CCCInt128, UnsignedFromString)
{
std::optional<u128> a(u128(0x123456789abcdef0, 0xffeeddccbbaa9988));
std::optional<u128> b(std::nullopt);
EXPECT_EQ(a, u128::from_string("123456789abcdef0ffEEddCCbbAA9988"));
EXPECT_EQ(b, u128::from_string("hello"));
std::optional<u128> a(u128(0x0, 0x123));
std::optional<u128> b(u128(0x1, 0x123));
std::optional<u128> c(u128(0x123456789abcdef0, 0xffeeddccbbaa9988));
std::optional<u128> d(std::nullopt);
EXPECT_EQ(a, u128::from_string("123"));
EXPECT_EQ(a, u128::from_string("123hello"));
EXPECT_EQ(a, u128::from_string("00000000000000000000000000000123"));
EXPECT_EQ(b, u128::from_string("10000000000000123"));
EXPECT_EQ(b, u128::from_string("00000000000000010000000000000123"));
EXPECT_EQ(c, u128::from_string("123456789abcdef0ffEEddCCbbAA9988"));
EXPECT_EQ(c, u128::from_string("ffffffff123456789abcdef0ffEEddCCbbAA9988"));
EXPECT_EQ(d, u128::from_string("hello"));
}

TEST(CCCInt128, SignedAdd)
Expand Down Expand Up @@ -208,8 +216,16 @@ TEST(CCCInt128, SignedToString)

TEST(CCCInt128, SignedFromString)
{
std::optional<s128> a(s128(0x123456789abcdef0, 0xffeeddccbbaa9988));
std::optional<s128> b(std::nullopt);
EXPECT_EQ(a, s128::from_string("123456789abcdef0ffEEddCCbbAA9988"));
EXPECT_EQ(b, s128::from_string("hello"));
std::optional<u128> a(u128(0x0, 0x123));
std::optional<u128> b(u128(0x1, 0x123));
std::optional<u128> c(u128(0x123456789abcdef0, 0xffeeddccbbaa9988));
std::optional<u128> d(std::nullopt);
EXPECT_EQ(a, u128::from_string("123"));
EXPECT_EQ(a, u128::from_string("123hello"));
EXPECT_EQ(a, u128::from_string("00000000000000000000000000000123"));
EXPECT_EQ(b, u128::from_string("10000000000000123"));
EXPECT_EQ(b, u128::from_string("00000000000000010000000000000123"));
EXPECT_EQ(c, u128::from_string("123456789abcdef0ffEEddCCbbAA9988"));
EXPECT_EQ(c, u128::from_string("ffffffff123456789abcdef0ffEEddCCbbAA9988"));
EXPECT_EQ(d, u128::from_string("hello"));;
}
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