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#include "exp.h"
#include "yaml-cpp/exceptions.h"
#include <sstream>
namespace YAML
{
namespace Exp
{
unsigned ParseHex(const std::string& str, const Mark& mark)
{
unsigned value = 0;
for(std::size_t i=0;i<str.size();i++) {
char ch = str[i];
int digit = 0;
if('a' <= ch && ch <= 'f')
digit = ch - 'a' + 10;
else if('A' <= ch && ch <= 'F')
digit = ch - 'A' + 10;
else if('0' <= ch && ch <= '9')
digit = ch - '0';
else
throw ParserException(mark, ErrorMsg::INVALID_HEX);
value = (value << 4) + digit;
}
return value;
}
std::string Str(unsigned ch)
{
return std::string(1, static_cast<char>(ch));
}
// Escape
// . Translates the next 'codeLength' characters into a hex number and returns the result.
// . Throws if it's not actually hex.
std::string Escape(Stream& in, int codeLength)
{
// grab string
std::string str;
for(int i=0;i<codeLength;i++)
str += in.get();
// get the value
unsigned value = ParseHex(str, in.mark());
// legal unicode?
if((value >= 0xD800 && value <= 0xDFFF) || value > 0x10FFFF) {
std::stringstream msg;
msg << ErrorMsg::INVALID_UNICODE << value;
throw ParserException(in.mark(), msg.str());
}
// now break it up into chars
if(value <= 0x7F)
return Str(value);
else if(value <= 0x7FF)
return Str(0xC0 + (value >> 6)) + Str(0x80 + (value & 0x3F));
else if(value <= 0xFFFF)
return Str(0xE0 + (value >> 12)) + Str(0x80 + ((value >> 6) & 0x3F)) + Str(0x80 + (value & 0x3F));
else
return Str(0xF0 + (value >> 18)) + Str(0x80 + ((value >> 12) & 0x3F)) +
Str(0x80 + ((value >> 6) & 0x3F)) + Str(0x80 + (value & 0x3F));
}
// Escape
// . Escapes the sequence starting 'in' (it must begin with a '\' or single quote)
// and returns the result.
// . Throws if it's an unknown escape character.
std::string Escape(Stream& in)
{
// eat slash
char escape = in.get();
// switch on escape character
char ch = in.get();
// first do single quote, since it's easier
if(escape == '\'' && ch == '\'')
return "\'";
// now do the slash (we're not gonna check if it's a slash - you better pass one!)
switch(ch) {
case '0': return std::string(1, '\x00');
case 'a': return "\x07";
case 'b': return "\x08";
case 't':
case '\t': return "\x09";
case 'n': return "\x0A";
case 'v': return "\x0B";
case 'f': return "\x0C";
case 'r': return "\x0D";
case 'e': return "\x1B";
case ' ': return "\x20";
case '\"': return "\"";
case '\'': return "\'";
case '\\': return "\\";
case '/': return "/";
case 'N': return "\x85";
case '_': return "\xA0";
case 'L': return "\xE2\x80\xA8"; // LS (#x2028)
case 'P': return "\xE2\x80\xA9"; // PS (#x2029)
case 'x': return Escape(in, 2);
case 'u': return Escape(in, 4);
case 'U': return Escape(in, 8);
}
std::stringstream msg;
throw ParserException(in.mark(), std::string(ErrorMsg::INVALID_ESCAPE) + ch);
}
}
}
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