ceph/src/boost/libs/metaparse/doc/repeated_reject_incomplete1.qbk

   1 [#repeated_reject_incomplete1]
   2 [section repeated_reject_incomplete1]
   3
   4 [h1 Synopsis]
   5
   6   template <class P>
   7   struct repeated_reject_incomplete1;
   8
   9 This 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
  18 The same as [link repeated1 `repeated1`], but once `P` rejects the input,
  19 `repeated_reject_incomplete1` checks if `P` consumes any characters before
  20 rejecting the input. If so, `repeated_reject_incomplete1` rejects the input with
  21 the same error message this last application of `P` returned. Otherwise
  22 _reject_incomplete`repeated1` accepts the input and gives the same result as
  23 [link repeated1 `repeated1`].
  24
  25 [h1 Header]
  26
  27   #include <boost/metaparse/repeated_reject_incomplete1.hpp>
  28
  29 [h1 Expression semantics]
  30
  31 For any  `p` parser, `s` compile-time string and `pos` source position
  32
  33   repeated_reject_incomplete1<p>::apply<s, pos>
  34
  35 is equivalent to
  36
  37   first_of<repeated1<p>, fail_at_first_char_expected<p> >::apply<s, pos>
  38
  39 [h1 Example]
  40
  41   #include <boost/metaparse/repeated_reject_incomplete1.hpp>
  42   #include <boost/metaparse/lit_c.hpp>
  43   #include <boost/metaparse/last_of.hpp>
  44   #include <boost/metaparse/token.hpp>
  45   #include <boost/metaparse/int_.hpp>
  46   #include <boost/metaparse/string.hpp>
  47   #include <boost/metaparse/start.hpp>
  48   #include <boost/metaparse/get_result.hpp>
  49   #include <boost/metaparse/is_error.hpp>
  50
  51   #include <boost/mpl/equal.hpp>
  52   #include <boost/mpl/vector_c.hpp>
  53
  54   using namespace boost::metaparse;
  55
  56   using int_token = token<int_>;
  57   using plus_token = token<lit_c<'+'>>;
  58   using plus_int = last_of<plus_token, int_token>;
  59
  60   using ints = repeated_reject_incomplete1<plus_int>;
  61
  62   static_assert(
  63     boost::mpl::equal<
  64       boost::mpl::vector_c<int, 13, 3, 21>,
  65       get_result<
  66         ints::apply<BOOST_METAPARSE_STRING("+ 13 + 3 + 21"), start>
  67       >::type
  68     >::type::value,
  69     "ints should parse the numbers"
  70   );
  71
  72   static_assert(
  73     is_error<
  74       ints::apply<BOOST_METAPARSE_STRING("+ 13 + 3 +"), start>
  75     >::type::value,
  76     "when the last number is missing, it should be an error"
  77   );
  78
  79   static_assert(
  80     is_error<ints::apply<BOOST_METAPARSE_STRING(""), start>>::type::value,
  81     "when no numbers are provided, it should be an error"
  82   );
  83
  84 [endsect]
  85