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Commit | Line | Data |
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1 | %debug | |
2 | %skeleton "lalr1.cc" | |
3 | %defines | |
4 | %define variant | |
5 | %define lex_symbol | |
6 | ||
7 | %code requires // *.hh | |
8 | { | |
9 | #include <list> | |
10 | #include <string> | |
11 | typedef std::list<std::string> strings_type; | |
12 | } | |
13 | ||
14 | %code // *.cc | |
15 | { | |
16 | #include <algorithm> | |
17 | #include <iostream> | |
18 | #include <iterator> | |
19 | #include <sstream> | |
20 | ||
21 | // Prototype of the yylex function providing subsequent tokens. | |
22 | static yy::parser::symbol_type yylex (); | |
23 | ||
24 | // Printing a list of strings. | |
25 | // Koening look up will look into std, since that's an std::list. | |
26 | namespace std | |
27 | { | |
28 | std::ostream& | |
29 | operator<< (std::ostream& o, const strings_type& s) | |
30 | { | |
31 | std::copy (s.begin (), s.end (), | |
32 | std::ostream_iterator<strings_type::value_type> (o, "\n")); | |
33 | return o; | |
34 | } | |
35 | } | |
36 | ||
37 | // Conversion to string. | |
38 | template <typename T> | |
39 | inline | |
40 | std::string | |
41 | string_cast (const T& t) | |
42 | { | |
43 | std::ostringstream o; | |
44 | o << t; | |
45 | return o.str (); | |
46 | } | |
47 | } | |
48 | ||
49 | %token <::std::string> TEXT; | |
50 | %token <int> NUMBER; | |
51 | %printer { debug_stream () << $$; } | |
52 | <int> <::std::string> <::std::list<std::string>>; | |
53 | %token END_OF_FILE 0; | |
54 | ||
55 | %type <::std::string> item; | |
56 | %type <::std::list<std::string>> list; | |
57 | ||
58 | %% | |
59 | ||
60 | result: | |
61 | list { std::cout << $1 << std::endl; } | |
62 | ; | |
63 | ||
64 | list: | |
65 | /* nothing */ { /* Generates an empty string list */ } | |
66 | | list item { std::swap ($$, $1); $$.push_back ($2); } | |
67 | ; | |
68 | ||
69 | item: | |
70 | TEXT { std::swap ($$, $1); } | |
71 | | NUMBER { $$ = string_cast ($1); } | |
72 | ; | |
73 | %% | |
74 | ||
75 | // The yylex function providing subsequent tokens: | |
76 | // TEXT "I have three numbers for you:" | |
77 | // NUMBER 1 | |
78 | // NUMBER 2 | |
79 | // NUMBER 3 | |
80 | // TEXT " and that's all!" | |
81 | // END_OF_FILE | |
82 | ||
83 | static | |
84 | yy::parser::symbol_type | |
85 | yylex () | |
86 | { | |
87 | static int stage = -1; | |
88 | switch (++stage) | |
89 | { | |
90 | case 0: | |
91 | return yy::parser::make_TEXT ("I have three numbers for you."); | |
92 | case 1: | |
93 | case 2: | |
94 | case 3: | |
95 | return yy::parser::make_NUMBER (stage); | |
96 | case 4: | |
97 | return yy::parser::make_TEXT ("And that's all!"); | |
98 | default: | |
99 | return yy::parser::make_END_OF_FILE (); | |
100 | } | |
101 | } | |
102 | ||
103 | // Mandatory error function | |
104 | void | |
105 | yy::parser::error (const std::string& message) | |
106 | { | |
107 | std::cerr << message << std::endl; | |
108 | } | |
109 | ||
110 | int | |
111 | main () | |
112 | { | |
113 | yy::parser p; | |
114 | p.set_debug_level (!!getenv ("YYDEBUG")); | |
115 | return p.parse (); | |
116 | } | |
117 | ||
118 | // Local Variables: | |
119 | // mode: C++ | |
120 | // End: |