1/*=============================================================================
2 Copyright (c) 2011 Jamboree
3 Copyright (c) 2014 Lee Clagett
4
5 Distributed under the Boost Software License, Version 1.0. (See accompanying
6 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7==============================================================================*/
8#if !defined(BOOST_SPIRIT_X3_SEEK_APRIL_13_2014_1920PM)
9#define BOOST_SPIRIT_X3_SEEK_APRIL_13_2014_1920PM
10
11#include <boost/spirit/home/x3/core/parser.hpp>
12
13namespace boost { namespace spirit { namespace x3
14{
15 template<typename Subject>
16 struct seek_directive : unary_parser<Subject, seek_directive<Subject>>
17 {
18 typedef unary_parser<Subject, seek_directive<Subject>> base_type;
19 static bool const is_pass_through_unary = true;
20 static bool const handles_container = Subject::handles_container;
21
22 constexpr seek_directive(Subject const& subject) :
23 base_type(subject) {}
24
25 template<typename Iterator, typename Context
26 , typename RContext, typename Attribute>
27 bool parse(
28 Iterator& first, Iterator const& last
29 , Context const& context, RContext& rcontext, Attribute& attr) const
30 {
31 for (Iterator current(first);; ++current)
32 {
33 if (this->subject.parse(current, last, context, rcontext, attr))
34 {
35 first = current;
36 return true;
37 }
38
39 // fail only after subject fails & no input
40 if (current == last)
41 return false;
42 }
43 }
44 };
45
46 struct seek_gen
47 {
48 template<typename Subject>
49 constexpr seek_directive<typename extension::as_parser<Subject>::value_type>
50 operator[](Subject const& subject) const
51 {
52 return { as_parser(subject) };
53 }
54 };
55
56 constexpr auto seek = seek_gen{};
57}}}
58
59#endif
60

source code of boost/libs/spirit/include/boost/spirit/home/x3/directive/seek.hpp