oxen-core/src/common/string_util.cpp
Jason Rhinelander 48a0dc9eef More string_view niceties
- Adds a tools::trim that operates on a string_view to replace boost
string trim usage.

- Replaces some boost::split's with tools::split's

- updates vercmp to operate on string_views instead of c strings
2020-07-02 12:52:13 -03:00

78 lines
2.1 KiB
C++

#include "string_util.h"
#include <cassert>
namespace tools {
using namespace std::literals;
std::vector<std::string_view> split(std::string_view str, const std::string_view delim, bool trim)
{
std::vector<std::string_view> results;
// Special case for empty delimiter: splits on each character boundary:
if (delim.empty())
{
results.reserve(str.size());
for (size_t i = 0; i < str.size(); i++)
results.emplace_back(str.data() + i, 1);
return results;
}
for (size_t pos = str.find(delim); pos != std::string_view::npos; pos = str.find(delim))
{
if (!trim || !results.empty() || pos > 0)
results.push_back(str.substr(0, pos));
str.remove_prefix(pos + delim.size());
}
if (!trim || str.size())
results.push_back(str);
else
while (!results.empty() && results.back().empty())
results.pop_back();
return results;
}
std::vector<std::string_view> split_any(std::string_view str, const std::string_view delims, bool trim)
{
if (delims.empty())
return split(str, delims);
std::vector<std::string_view> results;
for (size_t pos = str.find_first_of(delims); pos != std::string_view::npos; pos = str.find_first_of(delims))
{
if (!trim || !results.empty() || pos > 0)
results.push_back(str.substr(0, pos));
size_t until = str.find_first_not_of(delims, pos+1);
if (until == std::string_view::npos)
str.remove_prefix(str.size());
else
str.remove_prefix(until);
}
if (!trim || str.size())
results.push_back(str);
else
while (!results.empty() && results.back().empty())
results.pop_back();
return results;
}
void trim(std::string_view& s)
{
constexpr auto simple_whitespace = " \t\r\n"sv;
auto pos = s.find_first_not_of(simple_whitespace);
if (pos == std::string_view::npos) { // whole string is whitespace
s.remove_prefix(s.size());
return;
}
s.remove_prefix(pos);
pos = s.find_last_not_of(simple_whitespace);
assert(pos != std::string_view::npos);
s.remove_suffix(s.size() - (pos + 1));
}
std::string lowercase_ascii_string(std::string src)
{
for (char &ch : src)
if (ch >= 'A' && ch <= 'Z') ch = ch + ('a' - 'A');
return src;
}
}