kakoune/src/string.cc

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#include "string.hh"
2013-04-09 20:05:40 +02:00
#include "exception.hh"
#include "utils.hh"
#include "utf8_iterator.hh"
namespace Kakoune
{
bool operator<(StringView lhs, StringView rhs)
{
int cmp = strncmp(lhs.data(), rhs.data(), (int)std::min(lhs.length(), rhs.length()));
if (cmp == 0)
return lhs.length() < rhs.length();
return cmp < 0;
}
std::vector<String> split(StringView str, char separator, char escape)
{
std::vector<String> res;
auto it = str.begin();
while (it != str.end())
{
res.emplace_back();
String& element = res.back();
while (it != str.end())
{
auto c = *it;
if (c == escape and it + 1 != str.end() and *(it+1) == separator)
{
element += separator;
it += 2;
}
else if (c == separator)
{
++it;
break;
}
else
{
element += c;
++it;
}
}
}
return res;
}
std::vector<StringView> split(StringView str, char separator)
{
std::vector<StringView> res;
auto beg = str.begin();
for (auto it = beg; it != str.end(); ++it)
{
if (*it == separator)
{
res.emplace_back(beg, it);
beg = it + 1;
}
}
res.emplace_back(beg, str.end());
return res;
}
String escape(StringView str, char character, char escape)
{
String res;
for (auto& c : str)
{
if (c == character)
res += escape;
res += c;
}
return res;
}
String escape(StringView str, StringView characters, char escape)
{
String res;
for (auto& c : str)
{
if (contains(characters, c))
res += escape;
res += c;
}
return res;
}
int str_to_int(StringView str)
{
int res = 0;
if (sscanf(str.zstr(), "%i", &res) != 1)
throw runtime_error(str + "is not a number");
return res;
}
String to_string(int val)
{
char buf[16];
sprintf(buf, "%i", val);
return buf;
}
bool prefix_match(StringView str, StringView prefix)
{
auto it = str.begin();
for (auto& c : prefix)
{
if (it ==str.end() or *it++ != c)
return false;
}
return true;
}
bool subsequence_match(StringView str, StringView subseq)
{
auto it = str.begin();
for (auto& c : subseq)
{
if (it == str.end())
return false;
while (*it != c)
{
if (++it == str.end())
return false;
}
++it;
}
return true;
}
String expand_tabs(StringView line, CharCount tabstop, CharCount col)
{
String res;
using Utf8It = utf8::iterator<const char*>;
for (Utf8It it = line.begin(); it.base() < line.end(); ++it)
{
if (*it == '\t')
{
CharCount end_col = (col / tabstop + 1) * tabstop;
res += String{' ', end_col - col};
}
else
res += *it;
}
return res;
}
[[gnu::always_inline]]
static inline uint32_t rotl(uint32_t x, int8_t r)
{
return (x << r) | (x >> (32 - r));
}
[[gnu::always_inline]]
static inline uint32_t fmix(uint32_t h)
{
h ^= h >> 16;
h *= 0x85ebca6b;
h ^= h >> 13;
h *= 0xc2b2ae35;
h ^= h >> 16;
return h;
}
// murmur3 hash, based on https://github.com/PeterScott/murmur3
size_t hash_data(const char* input, size_t len)
{
const uint8_t* data = reinterpret_cast<const uint8_t*>(input);
uint32_t hash = 0x1235678;
constexpr uint32_t c1 = 0xcc9e2d51;
constexpr uint32_t c2 = 0x1b873593;
const int nblocks = len / 4;
const uint32_t* blocks = reinterpret_cast<const uint32_t*>(data + nblocks*4);
for (int i = -nblocks; i; ++i)
{
uint32_t key = blocks[i];
key *= c1;
key = rotl(key, 15);
key *= c2;
hash ^= key;
hash = rotl(hash, 13);
hash = hash * 5 + 0xe6546b64;
}
const uint8_t* tail = data + nblocks * 4;
uint32_t key = 0;
switch (len & 3)
{
case 3: key ^= tail[2] << 16;
case 2: key ^= tail[1] << 8;
case 1: key ^= tail[0];
key *= c1;
key = rotl(key,15);
key *= c2;
hash ^= key;
}
hash ^= len;
hash = fmix(hash);
return hash;
}
}