正在尝试为。fnt文件编写解析器:
int main()
{
const auto word = qi::lexeme [ + qi::alnum ];
const auto literal = qi::lexeme[ '"' >> + ( qi::char_ - '"' ) >> '"' ];
const auto value = literal | qi::double_;
const auto pair = word >> '=' >> value;
const auto line = word >> ( + pair ) >> qi::eol;
const auto document = + line;
std::ifstream in( "input.fnt" );
in.unsetf( std::ios::skipws );
boost::spirit::istream_iterator begin(in);
boost::spirit::istream_iterator end;
qi::parse( begin, end, document );
}
执行失败,在Boost::Spirit的deeps内出现分段错误错误。但是当我把文法改成不是由中间文法(规则?)-成功了。
在内部boost::spirit代码segfaults中说,解析复合语法时,表达式模板保留对临时语法的内部引用,但在qi::parse()调用期间,所有语法都存在。有什么问题吗?如何将复合语法分解成更有意义的部分?
附注。当将常量auto更改为define和remove=sign时-它成功:)(qi::parse()返回false,但至少返回ns。
给您一些除了重复之外的免费建议:将解析器赋给auto变量
让我们解析一下简单的FNT示例:
info face="Arial" size=32 bold=0 italic=0 charset="" unicode=1 stretchH=100 smooth=1 aa=1 padding=0,0,0,0 spacing=1,1 outline=0
common lineHeight=32 base=26 scaleW=256 scaleH=256 pages=0 packed=0 alphaChnl=1 redChnl=0 greenChnl=0 blueChnl=0
chars count=0
注意事项:
#define BOOST_SPIRIT_DEBUG
#include <boost/spirit/include/qi.hpp>
#include <fstream>
namespace qi = boost::spirit::qi;
int main() {
using It = boost::spirit::istream_iterator;
qi::rule<It>
word = +qi::alnum,
literal = '"' >> *(qi::char_ - '"') >> '"';
qi::rule<It, std::string()>
value = qi::raw[literal | qi::double_ % ','];
BOOST_SPIRIT_DEBUG_NODES((word)(literal)(value))
const auto pair = qi::copy(word >> '=' >> value);
const auto line = qi::copy(word >> ( + pair ) >> qi::eol);
const auto document = qi::copy(+ line);
std::ifstream in("input.fnt");
in.unsetf(std::ios::skipws);
It begin(in), end;
bool ok = qi::phrase_parse(begin, end, document, qi::blank);
std::cout << std::boolalpha << ok << '\n';
}
打印:
true
使用调试信息:
<word>
<try>info face="Arial" si</try>
<success> face="Arial" size=3</success>
<attributes>[]</attributes>
</word>
<word>
<try>face="Arial" size=32</try>
<success>="Arial" size=32 bol</success>
<attributes>[]</attributes>
</word>
<value>
<try>"Arial" size=32 bold</try>
<literal>
<try>"Arial" size=32 bold</try>
<success> size=32 bold=0 ital</success>
<attributes>[]</attributes>
</literal>
<success> size=32 bold=0 ital</success>
<attributes>[[", A, r, i, a, l, "]]</attributes>
</value>
<word>
<try>size=32 bold=0 itali</try>
<success>=32 bold=0 italic=0 </success>
<attributes>[]</attributes>
</word>
<value>
<try>32 bold=0 italic=0 c</try>
<literal>
<try>32 bold=0 italic=0 c</try>
<fail/>
</literal>
<success> bold=0 italic=0 cha</success>
<attributes>[[3, 2]]</attributes>
</value>
<word>
<try>bold=0 italic=0 char</try>
<success>=0 italic=0 charset=</success>
<attributes>[]</attributes>
</word>
<value>
<try>0 italic=0 charset="</try>
<literal>
<try>0 italic=0 charset="</try>
<fail/>
</literal>
<success> italic=0 charset=""</success>
<attributes>[[0]]</attributes>
</value>
<word>
<try>italic=0 charset="" </try>
<success>=0 charset="" unicod</success>
<attributes>[]</attributes>
</word>
<value>
<try>0 charset="" unicode</try>
<literal>
<try>0 charset="" unicode</try>
<fail/>
</literal>
<success> charset="" unicode=</success>
<attributes>[[0]]</attributes>
</value>
<word>
<try>charset="" unicode=1</try>
<success>="" unicode=1 stretc</success>
<attributes>[]</attributes>
</word>
<value>
<try>"" unicode=1 stretch</try>
<literal>
<try>"" unicode=1 stretch</try>
<success> unicode=1 stretchH=</success>
<attributes>[]</attributes>
</literal>
<success> unicode=1 stretchH=</success>
<attributes>[[", "]]</attributes>
</value>
<word>
<try>unicode=1 stretchH=1</try>
<success>=1 stretchH=100 smoo</success>
<attributes>[]</attributes>
</word>
<value>
<try>1 stretchH=100 smoot</try>
<literal>
<try>1 stretchH=100 smoot</try>
<fail/>
</literal>
<success> stretchH=100 smooth</success>
<attributes>[[1]]</attributes>
</value>
<word>
<try>stretchH=100 smooth=</try>
<success>=100 smooth=1 aa=1 p</success>
<attributes>[]</attributes>
</word>
<value>
<try>100 smooth=1 aa=1 pa</try>
<literal>
<try>100 smooth=1 aa=1 pa</try>
<fail/>
</literal>
<success> smooth=1 aa=1 paddi</success>
<attributes>[[1, 0, 0]]</attributes>
</value>
<word>
<try>smooth=1 aa=1 paddin</try>
<success>=1 aa=1 padding=0,0,</success>
<attributes>[]</attributes>
</word>
<value>
<try>1 aa=1 padding=0,0,0</try>
<literal>
<try>1 aa=1 padding=0,0,0</try>
<fail/>
</literal>
<success> aa=1 padding=0,0,0,</success>
<attributes>[[1]]</attributes>
</value>
<word>
<try>aa=1 padding=0,0,0,0</try>
<success>=1 padding=0,0,0,0 s</success>
<attributes>[]</attributes>
</word>
<value>
<try>1 padding=0,0,0,0 sp</try>
<literal>
<try>1 padding=0,0,0,0 sp</try>
<fail/>
</literal>
<success> padding=0,0,0,0 spa</success>
<attributes>[[1]]</attributes>
</value>
<word>
<try>padding=0,0,0,0 spac</try>
<success>=0,0,0,0 spacing=1,1</success>
<attributes>[]</attributes>
</word>
<value>
<try>0,0,0,0 spacing=1,1 </try>
<literal>
<try>0,0,0,0 spacing=1,1 </try>
<fail/>
</literal>
<success> spacing=1,1 outline</success>
<attributes>[[0, ,, 0, ,, 0, ,, 0]]</attributes>
</value>
<word>
<try>spacing=1,1 outline=</try>
<success>=1,1 outline=0\ncommo</success>
<attributes>[]</attributes>
</word>
<value>
<try>1,1 outline=0\ncommon</try>
<literal>
<try>1,1 outline=0\ncommon</try>
<fail/>
</literal>
<success> outline=0\ncommon li</success>
<attributes>[[1, ,, 1]]</attributes>
</value>
<word>
<try>outline=0\ncommon lin</try>
<success>=0\ncommon lineHeight</success>
<attributes>[]</attributes>
</word>
<value>
<try>0\ncommon lineHeight=</try>
<literal>
<try>0\ncommon lineHeight=</try>
<fail/>
</literal>
<success>\ncommon lineHeight=3</success>
<attributes>[[0]]</attributes>
</value>
<word>
<try>\ncommon lineHeight=3</try>
<fail/>
</word>
<word>
<try>common lineHeight=32</try>
<success> lineHeight=32 base=</success>
<attributes>[]</attributes>
</word>
<word>
<try>lineHeight=32 base=2</try>
<success>=32 base=26 scaleW=2</success>
<attributes>[]</attributes>
</word>
<value>
<try>32 base=26 scaleW=25</try>
<literal>
<try>32 base=26 scaleW=25</try>
<fail/>
</literal>
<success> base=26 scaleW=256 </success>
<attributes>[[3, 2]]</attributes>
</value>
<word>
<try>base=26 scaleW=256 s</try>
<success>=26 scaleW=256 scale</success>
<attributes>[]</attributes>
</word>
<value>
<try>26 scaleW=256 scaleH</try>
<literal>
<try>26 scaleW=256 scaleH</try>
<fail/>
</literal>
<success> scaleW=256 scaleH=2</success>
<attributes>[[2, 6]]</attributes>
</value>
<word>
<try>scaleW=256 scaleH=25</try>
<success>=256 scaleH=256 page</success>
<attributes>[]</attributes>
</word>
<value>
<try>256 scaleH=256 pages</try>
<literal>
<try>256 scaleH=256 pages</try>
<fail/>
</literal>
<success> scaleH=256 pages=0 </success>
<attributes>[[2, 5, 6]]</attributes>
</value>
<word>
<try>scaleH=256 pages=0 p</try>
<success>=256 pages=0 packed=</success>
<attributes>[]</attributes>
</word>
<value>
<try>256 pages=0 packed=0</try>
<literal>
<try>256 pages=0 packed=0</try>
<fail/>
</literal>
<success> pages=0 packed=0 al</success>
<attributes>[[2, 5, 6]]</attributes>
</value>
<word>
<try>pages=0 packed=0 alp</try>
<success>=0 packed=0 alphaChn</success>
<attributes>[]</attributes>
</word>
<value>
<try>0 packed=0 alphaChnl</try>
<literal>
<try>0 packed=0 alphaChnl</try>
<fail/>
</literal>
<success> packed=0 alphaChnl=</success>
<attributes>[[0]]</attributes>
</value>
<word>
<try>packed=0 alphaChnl=1</try>
<success>=0 alphaChnl=1 redCh</success>
<attributes>[]</attributes>
</word>
<value>
<try>0 alphaChnl=1 redChn</try>
<literal>
<try>0 alphaChnl=1 redChn</try>
<fail/>
</literal>
<success> alphaChnl=1 redChnl</success>
<attributes>[[0]]</attributes>
</value>
<word>
<try>alphaChnl=1 redChnl=</try>
<success>=1 redChnl=0 greenCh</success>
<attributes>[]</attributes>
</word>
<value>
<try>1 redChnl=0 greenChn</try>
<literal>
<try>1 redChnl=0 greenChn</try>
<fail/>
</literal>
<success> redChnl=0 greenChnl</success>
<attributes>[[1]]</attributes>
</value>
<word>
<try>redChnl=0 greenChnl=</try>
<success>=0 greenChnl=0 blueC</success>
<attributes>[]</attributes>
</word>
<value>
<try>0 greenChnl=0 blueCh</try>
<literal>
<try>0 greenChnl=0 blueCh</try>
<fail/>
</literal>
<success> greenChnl=0 blueChn</success>
<attributes>[[0]]</attributes>
</value>
<word>
<try>greenChnl=0 blueChnl</try>
<success>=0 blueChnl=0\nchars </success>
<attributes>[]</attributes>
</word>
<value>
<try>0 blueChnl=0\nchars c</try>
<literal>
<try>0 blueChnl=0\nchars c</try>
<fail/>
</literal>
<success> blueChnl=0\nchars co</success>
<attributes>[[0]]</attributes>
</value>
<word>
<try>blueChnl=0\nchars cou</try>
<success>=0\nchars count=0\n</success>
<attributes>[]</attributes>
</word>
<value>
<try>0\nchars count=0\n</try>
<literal>
<try>0\nchars count=0\n</try>
<fail/>
</literal>
<success>\nchars count=0\n</success>
<attributes>[[0]]</attributes>
</value>
<word>
<try>\nchars count=0\n</try>
<fail/>
</word>
<word>
<try>chars count=0\n</try>
<success> count=0\n</success>
<attributes>[]</attributes>
</word>
<word>
<try>count=0\n</try>
<success>=0\n</success>
<attributes>[]</attributes>
</word>
<value>
<try>0\n</try>
<literal>
<try>0\n</try>
<fail/>
</literal>
<success>\n</success>
<attributes>[[0]]</attributes>
</value>
<word>
<try>\n</try>
<fail/>
</word>
<word>
<try></try>
<fail/>
</word>