Added conditional restrictions grammar

2016-12-15 11:54:13 +01:00
parent 88eb9e5499
commit 7961fa8863
2 changed files with 149 additions and 0 deletions
@@ -0,0 +1,109 @@
+#ifndef OSRM_CONDITIONAL_RESTRICTIONS_HPP
+#define OSRM_CONDITIONAL_RESTRICTIONS_HPP
+
+#include <boost/fusion/include/adapt_struct.hpp>
+#include <boost/spirit/include/phoenix.hpp>
+#include <boost/spirit/include/qi.hpp>
+
+namespace osrm
+{
+namespace util
+{
+
+// Helper functions for OSM conditional restrictions
+// http://wiki.openstreetmap.org/wiki/Conditional_restrictions
+// Consitional restrictions is a vector of ConditionalRestriction
+// with a restriction value and a condition string
+struct ConditionalRestriction
+{
+    std::string value;
+    std::string condition;
+};
+
+#ifndef NDEBUG
+// Debug output stream operators for use with BOOST_SPIRIT_DEBUG
+inline std::ostream &operator<<(std::ostream &stream, const ConditionalRestriction &restriction)
+{
+    return stream << restriction.value << "=" << restriction.condition;
+}
+#endif
+}
+}
+
+BOOST_FUSION_ADAPT_STRUCT(osrm::util::ConditionalRestriction,
+                          (std::string, value)(std::string, condition))
+
+namespace osrm
+{
+namespace util
+{
+namespace detail
+{
+
+namespace
+{
+namespace ph = boost::phoenix;
+namespace qi = boost::spirit::qi;
+}
+
+template <typename Iterator, typename Skipper = qi::blank_type>
+struct conditional_restrictions_grammar
+    : qi::grammar<Iterator, Skipper, std::vector<ConditionalRestriction>()>
+{
+    // http://wiki.openstreetmap.org/wiki/Conditional_restrictions
+    conditional_restrictions_grammar() : conditional_restrictions_grammar::base_type(restrictions)
+    {
+        using qi::_1;
+        using qi::_val;
+        using qi::lit;
+
+        // clang-format off
+
+        restrictions
+            = restriction % ';'
+            ;
+
+        restriction
+            = value >> '@' >> condition
+            ;
+
+        value
+            = +(qi::char_ - '@')
+            ;
+
+        condition
+            = *qi::blank
+            >> (lit('(') >> qi::as_string[qi::no_skip[*~lit(')')]][_val = _1] >> lit(')')
+                | qi::as_string[qi::no_skip[*~lit(';')]][_val = _1]
+               )
+            ;
+
+        // clang-format on
+
+        BOOST_SPIRIT_DEBUG_NODES((restrictions)(restriction)(value)(condition));
+    }
+
+    qi::rule<Iterator, Skipper, std::vector<ConditionalRestriction>()> restrictions;
+    qi::rule<Iterator, Skipper, ConditionalRestriction()> restriction;
+    qi::rule<Iterator, Skipper, std::string()> value, condition;
+};
+}
+
+inline std::vector<ConditionalRestriction> ParseConditionalRestrictions(const std::string &str)
+{
+    auto it(str.begin()), end(str.end());
+    const detail::conditional_restrictions_grammar<decltype(it)> static grammar;
+
+    std::vector<ConditionalRestriction> result;
+    bool ok = boost::spirit::qi::phrase_parse(it, end, grammar, boost::spirit::qi::blank, result);
+
+    if (!ok || it != end)
+        return std::vector<ConditionalRestriction>();
+
+    return result;
+}
+
+} // util
+} // osrm
+
+#endif // OSRM_CONDITIONAL_RESTRICTIONS_HPP