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#include "sass.hpp" 
#include <string> 
#include <vector> 
#include <cstdlib> 
#include <cmath> 
 
#include "utf8.h" 
 
namespace Sass { 
  namespace UTF_8 { 
    using std::string; 
 
    // naming conventions: 
    // offset: raw byte offset (0 based) 
    // position: code point offset (0 based) 
    // index: code point offset (1 based or negative) 
 
    // function that will count the number of code points (utf-8 characters) from the given beginning to the given end 
    size_t code_point_count(const string& str, size_t start, size_t end) { 
      return utf8::distance(str.begin() + start, str.begin() + end); 
    } 
 
    size_t code_point_count(const string& str) { 
      return utf8::distance(str.begin(), str.end()); 
    } 
 
    // function that will return the byte offset at a code point position 
    size_t offset_at_position(const string& str, size_t position) { 
      string::const_iterator it = str.begin(); 
      utf8::advance(it, position, str.end()); 
      return std::distance(str.begin(), it); 
    } 
 
    // function that returns number of bytes in a character at offset 
    size_t code_point_size_at_offset(const string& str, size_t offset) { 
      // get iterator from string and forward by offset 
      string::const_iterator stop = str.begin() + offset; 
      // check if beyond boundary 
      if (stop == str.end()) return 0; 
      // advance by one code point 
      utf8::advance(stop, 1, str.end()); 
      // calculate offset for code point 
      return  stop - str.begin() - offset; 
    } 
 
    // function that will return a normalized index, given a crazy one 
    size_t normalize_index(int index, size_t len) { 
      long signed_len = static_cast<long>(len); 
      // assuming the index is 1-based 
      // we are returning a 0-based index 
      if (index > 0 && index <= signed_len) { 
        // positive and within string length 
        return index-1; 
      } 
      else if (index > signed_len) { 
        // positive and past string length 
        return len; 
      } 
      else if (index == 0) { 
        return 0; 
      } 
      else if (std::abs((double)index) <= signed_len) { 
        // negative and within string length 
        return index + signed_len; 
      } 
      else { 
        // negative and past string length 
        return 0; 
      } 
    } 
 
    #ifdef _WIN32 
 
    // utf16 functions 
    using std::wstring; 
 
    // convert from utf16/wide string to utf8 string 
    string convert_from_utf16(const wstring& utf16) 
    { 
      string utf8; 
      // pre-allocate expected memory 
      utf8.reserve(sizeof(utf16)/2); 
      utf8::utf16to8(utf16.begin(), utf16.end(), 
                     back_inserter(utf8)); 
      return utf8; 
    } 
 
    // convert from utf8 string to utf16/wide string 
    wstring convert_to_utf16(const string& utf8) 
    { 
      wstring utf16; 
      // pre-allocate expected memory 
      utf16.reserve(code_point_count(utf8)*2); 
      utf8::utf8to16(utf8.begin(), utf8.end(), 
                     back_inserter(utf16)); 
      return utf16; 
    } 
 
    #endif 
 
  } 
}