EQ2EMu/EQ2/source/depends/boost_1_72_0/libs/metaparse/doc/repeated_one_of1.qbk

[#repeated_one_of1]
[section repeated_one_of1]

[h1 Synopsis]

  template <class... Ps>
  struct repeated_one_of1;

This is a [link parser_combinator parser combinator].

[table Arguments
  [[Name] [Type]]
  [[`Ps`] [[link parser parser]s]]
]

[h1 Description]

It applies the `Ps...` parsers repeatedly as long as any of them accepts the
input. In each iteration the parsers are tried in order and the first one
accepting the input is used, therefore in case of ambiguous grammars the result
of parsing depends on the order of the `Ps...` parsers. The result of parsing
with this [link parser_combinator parser combinator] is a sequence of the
individual parsing results.

When none of the `Ps...` parsers accept the input in the first iteration,
`repeated_one_of1` rejects the input.

On compilers, which are not C++11-compliant, the maximum number of accepted
parsers is defined by the `BOOST_METAPARSE_LIMIT_ONE_OF_SIZE` macro. Its default
value is 20.

[h1 Header]

  #include <boost/metaparse/repeated_one_of1.hpp>

[h1 Expression semantics]

For any `p1`, ..., `pn` parsers

  repeated_one_of1<p1, /* ... */, pn>

is equivalent to

  repeated1<one_of<p1, /* ... */, pn>>

[h1 Example]

  #include <boost/metaparse/repeated_one_of1.hpp>
  #include <boost/metaparse/lit_c.hpp>
  #include <boost/metaparse/start.hpp>
  #include <boost/metaparse/string.hpp>
  #include <boost/metaparse/get_result.hpp>
  #include <boost/metaparse/is_error.hpp>
  
  #include <boost/mpl/equal.hpp>
  #include <boost/mpl/vector.hpp>
  #include <boost/mpl/char.hpp>
  
  using namespace boost::metaparse;
  
  using as_and_bs = repeated_one_of1<lit_c<'a'>, lit_c<'b'>>;
  
  static_assert(
    boost::mpl::equal<
      get_result<as_and_bs::apply<BOOST_METAPARSE_STRING("abaab"), start>>::type,
      boost::mpl::vector<
        boost::mpl::char_<'a'>,
        boost::mpl::char_<'b'>,
        boost::mpl::char_<'a'>,
        boost::mpl::char_<'a'>,
        boost::mpl::char_<'b'>
      >
    >::type::value,
    "the result of parsing should be the list of results"
  );
  
  static_assert(
    is_error<as_and_bs::apply<BOOST_METAPARSE_STRING("x"), start>>::type::value,
    "repeated_one_of1 should reject the input when it"
    " can't parse anything with digit_val"
  );

[endsect]