将重复语句的结果存储到std :: vector会导致编译错误:
/usr/include/boost/spirit/home/qi/detail/pass_container.hpp:172:12: error: ambiguous
class template instantiation for ‘struct boost::spirit::qi::detail::pass_through_container_base<std::vector<Vertex3d<float> >, Vertex3d<float>, Vertex3d<float>, mpl_::bool_<false>, void>’
/usr/include/boost/spirit/home/qi/detail/pass_container.hpp:103:12: error: candidates are: struct boost::spirit::qi::detail::pass_through_container_base<Container, ValueType, Attribute, Sequence, typename boost::enable_if<boost::fusion::traits::is_sequence<Attribute> >::type>
struct pass_through_container_base<Container, ValueType, Attribute
^
/usr/include/boost/spirit/home/qi/detail/pass_container.hpp:136:12: error: struct boost::spirit::qi::detail::pass_through_container_base<Container, ValueType, Attribute, Sequence, typename boost::enable_if<boost::spirit::traits::is_container<T2> >::type>
struct pass_through_container_base<
^
/usr/include/boost/spirit/home/qi/detail/pass_container.hpp:172:12: error: invalid use of incomplete type ‘struct boost::spirit::qi::detail::pass_through_container_base<std::vector<wc3lib::Vertex3d<float> >, wc3lib::Vertex3d<float>, wc3lib::Vertex3d<float>, mpl_::bool_<false>, void>’
struct pass_through_container
^
/usr/include/boost/spirit/home/qi/detail/pass_container.hpp:50:12: error: declaration of ‘struct boost::spirit::qi::detail::pass_through_container_base<std::vector<wc3lib::Vertex3d<float> >, wc3lib::Vertex3d<float>, wc3lib::Vertex3d<float>, mpl_::bool_<false>, void>’
struct pass_through_container_base
以下代码用于语法:
qi::rule<Iterator, long32(), Skipper> integer_literal;
qi::rule<Iterator, float32(), Skipper> real_literal;
qi::rule<Iterator, VertexReal3d(), Skipper> vertex_real_3d;
qi::rule<Iterator, Geoset::Vertices(), Skipper, qi::locals<long32> > vertices;
integer_literal %=
lexeme[
qi::int_parser<long32>()
]
;
real_literal %=
lexeme[
qi::real_parser<float32>()
]
;
vertex_real_3d =
lit('{')
>> real_literal[at_c<0>(_val) = _1]
>> lit(',')
>> real_literal[at_c<1>(_val) = _1]
>> lit(',')
>> real_literal[at_c<2>(_val) = _1]
>> lit('}')
;
vertices =
lit("Vertices")
>> integer_literal[_a = _1]
>> lit('{')
>> repeat(_a)[
vertex_real_3d
>> lit(',')
][_val = _1] // Does not work?
>> lit('}')
;
...
typedef Vertex3d<float32> VertexData;
typedef VertexData VertexReal3d;
typedef std::vector<VertexData> Vertices;
...
BOOST_FUSION_ADAPT_ADT(
wc3lib::mdlx::VertexData,
(wc3lib::float32, wc3lib::float32, obj[0], obj[0] = val)
(wc3lib::float32, wc3lib::float32, obj[1], obj[1] = val)
(wc3lib::float32, wc3lib::float32, obj[2], obj[2] = val)
)
...
template<typename T, typename std::size_t N>
class BasicVertex : public std::array<T, N>
{
public:
typedef std::array<T, N> Base;
BasicVertex() : Base()
{
}
BasicVertex(const BasicVertex<T, N> &other) : Base(other) {
}
};
template<typename T = float32>
class Vertex3d : public BasicVertex<T, 3>
{
public:
typedef BasicVertex<T, 3> Base;
Vertex3d() : Base()
{
}
Vertex3d(T x, T y, T z)
{
(*this)[0] = x;
(*this)[1] = y;
(*this)[2] = z;
}
Vertex3d(const Base &other) : Base(other) {
}
};
规则顶点应返回VertexData的std :: vector.因此,重复用于解析固定数量的顶点.金额在整理列表之前的解析文件中作为整数值存储在_a中.
编译错误提示它不能在"is_sequence"和"is_container"之间有所不同.我不是灵的专家,所以我无法回答它究竟意味着什么.
这是我自己制作的结果.
我选择了改编VectorData类型.(我注意到你可能没有太晚了).
这使得语法变得复杂.我不确定究竟什么不起作用,因为在代码编译它确实有效的时候......
因此,让我们在代码清理和示例中进行另一个练习:
删除了','这里所需的古怪:
'{' >> repeat(_a)[ vertex_real_3d >> (',' | &lit('}')) ] >> '}'
删除了多余的用途 operator%=
qi::lit()qi::locals<>在语法声明中公开(这是一个实现细节)现在代码时钟为77行(比以前减少25行):
//#define BOOST_SPIRIT_DEBUG
#include <boost/fusion/adapted/struct.hpp>
#include <boost/spirit/include/phoenix.hpp>
#include <boost/spirit/include/qi.hpp>
namespace qi = boost::spirit::qi;
using long32 = int32_t;
using float32 = float;
namespace Geoset {
template <typename T>
struct Vertex3d {
T a,b,c;
};
typedef Vertex3d<float32> VertexData;
typedef VertexData VertexReal3d;
typedef std::vector<VertexData> Vertices;
}
BOOST_FUSION_ADAPT_STRUCT(Geoset::VertexData, (float32, a)(float32, b)(float32, c))
template <typename Iterator, typename Skipper = qi::space_type>
struct grammar : qi::grammar<Iterator, Geoset::Vertices(), Skipper> {
grammar() : grammar::base_type(start) {
using namespace qi;
vertex_real_3d =
'{' >> real_literal >> ','
>> real_literal >> ','
>> real_literal >> '}'
;
vertices %=
"Vertices"
>> omit [ integer_literal[_a = _1] ]
>> '{' >> repeat(_a)[ vertex_real_3d >> (',' | &lit('}')) ] >> '}'
;
start = vertices;
BOOST_SPIRIT_DEBUG_NODES((start)(vertices)(vertex_real_3d))
}
private:
qi::int_parser<long32> integer_literal;
qi::real_parser<float32> real_literal;
qi::rule<Iterator, Geoset::VertexReal3d(), Skipper> vertex_real_3d;
qi::rule<Iterator, Geoset::Vertices(), Skipper, qi::locals<long32> > vertices;
qi::rule<Iterator, Geoset::Vertices(), Skipper> start;
};
int main() {
std::string const input = "Vertices 4 { \n"
" { 1, 2, 3 }, \n"
" { 4, 5, 6 }, \n"
" { 7, 8, 9 }, \n"
" { 10, 11, 12 } \n"
"}";
auto f(begin(input)), l(end(input));
grammar<std::string::const_iterator> g;
Geoset::Vertices vertices;
bool ok = qi::phrase_parse(f,l,g,qi::space,vertices);
if (ok) {
std::cout << "Parsed: " << vertices.size() << "\n";
for (auto& v : vertices)
std::cout << boost::fusion::as_vector(v) << "\n";
} else
std::cout << "Parse failed\n";
if (f!=l)
std::cout << "Remaining input: '" << std::string(f,l) << "'\n";
}