1[#repeated_reject_incomplete] 2[section repeated_reject_incomplete] 3 4[h1 Synopsis] 5 6 template <class P> 7 struct repeated_reject_incomplete; 8 9This is a [link parser_combinator parser combinator]. 10 11[table Arguments 12 [[Name] [Type]] 13 [[`P`] [[link parser parser]]] 14] 15 16[h1 Description] 17 18The same as [link repeated `repeated`], but once `P` rejects the input, 19`repeated_reject_incomplete` checks if `P` consumes any characters before 20rejecting the input. If so, `repeated_reject_incomplete` rejects the input with 21the same error message this last application of `P` returned. Otherwise 22`repeated_reject_incomplete` accepts the input and gives the same result as 23[link repeated `repeated`]. 24 25Here is a diagram showing how `repeated_reject_incomplete` works by example: 26 27 using int_token = token<int_>; 28 using plus_token = token<lit_c<'+'>>; 29 using plus_int = last_of<plus_token, int_token>; 30 using sum_op = mpl::lambda<mpl::plus<mpl::_1, mpl::_2>>::type; 31 32[$images/metaparse/repeated_reject_incomplete_diag1.png [width 70%]] 33 34[h1 Header] 35 36 #include <boost/metaparse/repeated_reject_incomplete.hpp> 37 38[h1 Expression semantics] 39 40For any `p` parser, `s` compile-time string and `pos` source position 41 42 repeated_reject_incomplete<p>::apply<s, pos> 43 44is equivalent to 45 46 first_of<repeated<p>, fail_at_first_char_expected<p> >::apply<s, pos> 47 48[h1 Example] 49 50 #include <boost/metaparse/repeated_reject_incomplete.hpp> 51 #include <boost/metaparse/lit_c.hpp> 52 #include <boost/metaparse/last_of.hpp> 53 #include <boost/metaparse/token.hpp> 54 #include <boost/metaparse/int_.hpp> 55 #include <boost/metaparse/string.hpp> 56 #include <boost/metaparse/start.hpp> 57 #include <boost/metaparse/get_result.hpp> 58 #include <boost/metaparse/is_error.hpp> 59 60 #include <boost/mpl/equal.hpp> 61 #include <boost/mpl/vector_c.hpp> 62 63 using namespace boost::metaparse; 64 65 using int_token = token<int_>; 66 using plus_token = token<lit_c<'+'>>; 67 using plus_int = last_of<plus_token, int_token>; 68 69 using ints = repeated_reject_incomplete<plus_int>; 70 71 static_assert( 72 boost::mpl::equal< 73 boost::mpl::vector_c<int, 13, 3, 21>, 74 get_result< 75 ints::apply<BOOST_METAPARSE_STRING("+ 13 + 3 + 21"), start> 76 >::type 77 >::type::value, 78 "ints should parse the numbers" 79 ); 80 81 static_assert( 82 is_error< 83 ints::apply<BOOST_METAPARSE_STRING("+ 13 + 3 +"), start> 84 >::type::value, 85 "when the last number is missing, it should be an error" 86 ); 87 88[endsect] 89 90
