1/*
2  Copyright (C) 2008-2015, 2018-2021 Free Software Foundation, Inc.
3
4  This program is free software: you can redistribute it and/or modify
5  it under the terms of the GNU General Public License as published by
6  the Free Software Foundation, either version 3 of the License, or
7  (at your option) any later version.
8
9  This program is distributed in the hope that it will be useful,
10  but WITHOUT ANY WARRANTY; without even the implied warranty of
11  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  GNU General Public License for more details.
13
14  You should have received a copy of the GNU General Public License
15  along with this program.  If not, see <https://www.gnu.org/licenses/>.
16*/
17
18%require "3.2"
19%debug
20%language "c++"
21%define api.token.constructor
22%define api.value.type variant
23%define api.location.file none
24%define parse.assert
25%locations
26
27%code requires // *.hh
28{
29#include <string>
30#include <vector>
31typedef std::vector<std::string> strings_type;
32}
33
34%code // *.cc
35{
36#include <iostream>
37#include <sstream>
38
39  namespace yy
40  {
41    // Prototype of the yylex function providing subsequent tokens.
42    static parser::symbol_type yylex ();
43
44    // Print a vector of strings.
45    std::ostream&
46    operator<< (std::ostream& o, const strings_type& ss)
47    {
48      o << '{';
49      const char *sep = "";
50      for (strings_type::const_iterator i = ss.begin (), end = ss.end ();
51           i != end; ++i)
52        {
53          o << sep << *i;
54          sep = ", ";
55        }
56      return o << '}';
57    }
58  }
59
60  // Convert to string.
61  template <typename T>
62    std::string
63    to_string (const T& t)
64  {
65    std::ostringstream o;
66    o << t;
67    return o.str ();
68  }
69}
70
71%token <::std::string> TEXT;
72%token <int> NUMBER;
73%printer { yyo << '(' << &$$ << ") " << $$; } <*>;
74%token END_OF_FILE 0;
75
76%type <::std::string> item;
77%type <::std::vector<std::string>> list;
78
79%%
80
81result:
82  list  { std::cout << $1 << '\n'; }
83;
84
85list:
86  %empty     { /* Generates an empty string list */ }
87| list item  { std::swap ($$, $1); $$.push_back ($2); }
88;
89
90item:
91  TEXT
92| NUMBER  { $$ = to_string ($1); }
93;
94%%
95
96namespace yy
97{
98  // Use nullptr with pre-C++11.
99#if !defined __cplusplus || __cplusplus < 201103L
100# define NULLPTR 0
101#else
102# define NULLPTR nullptr
103#endif
104
105  // The yylex function providing subsequent tokens:
106  // TEXT         "I have three numbers for you."
107  // NUMBER       1
108  // NUMBER       2
109  // NUMBER       3
110  // TEXT         "And that's all!"
111  // END_OF_FILE
112
113  static
114  parser::symbol_type
115  yylex ()
116  {
117    static int count = 0;
118    const int stage = count;
119    ++count;
120    parser::location_type loc (NULLPTR, stage + 1, stage + 1);
121    switch (stage)
122      {
123      case 0:
124        return parser::make_TEXT ("I have three numbers for you.", loc);
125      case 1:
126      case 2:
127      case 3:
128        return parser::make_NUMBER (stage, loc);
129      case 4:
130        return parser::make_TEXT ("And that's all!", loc);
131      default:
132        return parser::make_END_OF_FILE (loc);
133      }
134  }
135
136  // Mandatory error function
137  void
138  parser::error (const parser::location_type& loc, const std::string& msg)
139  {
140    std::cerr << loc << ": " << msg << '\n';
141  }
142}
143
144int
145main ()
146{
147  yy::parser p;
148  p.set_debug_level (!!getenv ("YYDEBUG"));
149  return p.parse ();
150}
151
152// Local Variables:
153// mode: C++
154// End:
155