parser.hpp

#pragma once
 
#include "ast.hpp"
#include <boost/fusion/include/std_pair.hpp>
#include <boost/fusion/include/vector.hpp>
#include <boost/spirit/home/x3.hpp>
 
namespace quetzal
{
using boost::spirit::x3::parse;
namespace format::newick::parser
{
namespace x3 = boost::spirit::x3;
 
static x3::rule<class branch, ast::node> const node{"node"};
 
static auto const name = x3::lexeme[x3::alpha >> *x3::alnum];
static auto const length = ':' >> x3::double_ | x3::attr(0.0);
static auto const leaf = name | x3::attr(std::string{});
static auto const children = '(' >> (node % ',') >> ')' | x3::attr(ast::nodes{});
static auto const node_def = children >> leaf >> -length;
static auto const tree = x3::skip(x3::blank)[node >> ';' >> x3::eoi];
 
BOOST_SPIRIT_DEFINE(node);
 
template <typename ExpectedAttributeType> void compatible(auto p)
{
    static_assert(
        std::is_same_v<ExpectedAttributeType,
                       typename x3::traits::attribute_of<decltype(x3::rule<struct _, ExpectedAttributeType>{} = p),
                                                         x3::unused_type>::type>);
};
 
void checks()
{
    compatible<double>(length);
    compatible<std::string>(leaf);
    compatible<std::string>(name);
    compatible<ast::nodes>(children);
    compatible<ast::node>(tree);
}
} // namespace format::newick::parser
 
} // namespace quetzal