1 //  Copyright (c) 2001-2011 Hartmut Kaiser
2 //
3 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
4 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
5 
6 #if !defined(BOOST_SPIRIT_KARMA_COLUMNS_DEC_03_2009_0736AM)
7 #define BOOST_SPIRIT_KARMA_COLUMNS_DEC_03_2009_0736AM
8 
9 #if defined(_MSC_VER)
10 #pragma once
11 #endif
12 
13 #include <boost/spirit/home/karma/meta_compiler.hpp>
14 #include <boost/spirit/home/karma/generator.hpp>
15 #include <boost/spirit/home/karma/domain.hpp>
16 #include <boost/spirit/home/karma/delimit_out.hpp>
17 #include <boost/spirit/home/karma/detail/default_width.hpp>
18 #include <boost/spirit/home/karma/auxiliary/eol.hpp>
19 #include <boost/spirit/home/karma/auxiliary/lazy.hpp>
20 #include <boost/spirit/home/support/unused.hpp>
21 #include <boost/spirit/home/support/common_terminals.hpp>
22 #include <boost/spirit/home/support/has_semantic_action.hpp>
23 #include <boost/spirit/home/support/handles_container.hpp>
24 #include <boost/spirit/home/karma/detail/attributes.hpp>
25 #include <boost/spirit/home/support/info.hpp>
26 #include <boost/fusion/include/at.hpp>
27 #include <boost/fusion/include/vector.hpp>
28 #include <boost/integer_traits.hpp>
29 
30 namespace boost { namespace spirit
31 {
32     ///////////////////////////////////////////////////////////////////////////
33     // Enablers
34     ///////////////////////////////////////////////////////////////////////////
35     template <>
36     struct use_directive<karma::domain, tag::columns>   // enables columns[]
37       : mpl::true_ {};
38 
39     // enables columns(c)[g], where c provides the number of require columns
40     template <typename T>
41     struct use_directive<karma::domain
42           , terminal_ex<tag::columns, fusion::vector1<T> > >
43       : mpl::true_ {};
44 
45     // enables *lazy* columns(c)[g]
46     template <>
47     struct use_lazy_directive<karma::domain, tag::columns, 1>
48       : mpl::true_ {};
49 
50     // enables columns(c, d)[g], where c provides the number of require columns
51     // and d is the custom column-delimiter (default is karma::endl)
52     template <typename T1, typename T2>
53     struct use_directive<karma::domain
54           , terminal_ex<tag::columns, fusion::vector2<T1, T2> > >
55       : boost::spirit::traits::matches<karma::domain, T2> {};
56 
57     // enables *lazy* columns(c, d)[g]
58     template <>
59     struct use_lazy_directive<karma::domain, tag::columns, 2>
60       : mpl::true_ {};
61 
62 }}
63 
64 namespace boost { namespace spirit { namespace karma
65 {
66 #ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
67     using spirit::columns;
68 #endif
69     using spirit::columns_type;
70 
71     namespace detail
72     {
73         template <typename Delimiter, typename ColumnDelimiter>
74         struct columns_delimiter
75         {
columns_delimiterboost::spirit::karma::detail::columns_delimiter76             columns_delimiter(Delimiter const& delim
77                   , ColumnDelimiter const& cdelim, unsigned int const numcols)
78               : delimiter(delim), column_delimiter(cdelim)
79               , numcolumns(numcols), count(0) {}
80 
81             template <typename OutputIterator, typename Context
82               , typename Delimiter_, typename Attribute>
generateboost::spirit::karma::detail::columns_delimiter83             bool generate(OutputIterator& sink, Context&, Delimiter_ const&
84               , Attribute const&) const
85             {
86                 // first invoke the embedded delimiter
87                 if (!karma::delimit_out(sink, delimiter))
88                     return false;
89 
90                 // now we count the number of invocations and emit the column
91                 // delimiter if needed
92                 if ((++count % numcolumns) == 0)
93                     return karma::delimit_out(sink, column_delimiter);
94                 return true;
95             }
96 
97             // generate a final column delimiter if the last invocation didn't
98             // emit one
99             template <typename OutputIterator>
delimit_outboost::spirit::karma::detail::columns_delimiter100             bool delimit_out(OutputIterator& sink) const
101             {
102                 if (count % numcolumns)
103                     return karma::delimit_out(sink, column_delimiter);
104                 return true;
105             }
106 
107             Delimiter const& delimiter;
108             ColumnDelimiter const& column_delimiter;
109             unsigned int const numcolumns;
110             mutable unsigned int count;
111 
112             // silence MSVC warning C4512: assignment operator could not be generated
113             BOOST_DELETED_FUNCTION(columns_delimiter& operator= (columns_delimiter const&))
114         };
115     }
116 
117     ///////////////////////////////////////////////////////////////////////////
118     //  The columns_generator is used for columns(c, d)[...] directives.
119     ///////////////////////////////////////////////////////////////////////////
120     template <typename Subject, typename NumColumns, typename ColumnsDelimiter>
121     struct columns_generator
122       : unary_generator<columns_generator<Subject, NumColumns, ColumnsDelimiter> >
123     {
124         typedef Subject subject_type;
125         typedef ColumnsDelimiter delimiter_type;
126 
127         typedef mpl::int_<
128             subject_type::properties::value | delimiter_type::properties::value
129         > properties;
130 
131         template <typename Context, typename Iterator>
132         struct attribute
133           : traits::attribute_of<subject_type, Context, Iterator>
134         {};
135 
columns_generatorboost::spirit::karma::columns_generator136         columns_generator(Subject const& subject, NumColumns const& cols
137               , ColumnsDelimiter const& cdelimiter)
138           : subject(subject), numcolumns(cols), column_delimiter(cdelimiter)
139         {
140             // having zero number of columns doesn't make any sense
141             BOOST_ASSERT(numcolumns > 0);
142         }
143 
144         template <typename OutputIterator, typename Context
145           , typename Delimiter, typename Attribute>
generateboost::spirit::karma::columns_generator146         bool generate(OutputIterator& sink, Context& ctx
147           , Delimiter const& delimiter, Attribute const& attr) const
148         {
149             //  The columns generator dispatches to the embedded generator
150             //  while supplying a new delimiter to use, wrapping the outer
151             //  delimiter.
152             typedef detail::columns_delimiter<
153                 Delimiter, ColumnsDelimiter
154             > columns_delimiter_type;
155 
156             columns_delimiter_type d(delimiter, column_delimiter, numcolumns);
157             return subject.generate(sink, ctx, d, attr) && d.delimit_out(sink);
158         }
159 
160         template <typename Context>
whatboost::spirit::karma::columns_generator161         info what(Context& context) const
162         {
163             return info("columns", subject.what(context));
164         }
165 
166         Subject subject;
167         NumColumns numcolumns;
168         ColumnsDelimiter column_delimiter;
169     };
170 
171     ///////////////////////////////////////////////////////////////////////////
172     // Generator generators: make_xxx function (objects)
173     ///////////////////////////////////////////////////////////////////////////
174 
175     // creates columns[] directive
176     template <typename Subject, typename Modifiers>
177     struct make_directive<tag::columns, Subject, Modifiers>
178     {
179         typedef typename
180             result_of::compile<karma::domain, eol_type, Modifiers>::type
181         columns_delimiter_type;
182         typedef columns_generator<
183             Subject, detail::default_columns, columns_delimiter_type>
184         result_type;
185 
operator ()boost::spirit::karma::make_directive186         result_type operator()(unused_type, Subject const& subject
187           , unused_type) const
188         {
189 #if defined(BOOST_SPIRIT_NO_PREDEFINED_TERMINALS)
190             eol_type const eol = eol_type();
191 #endif
192             return result_type(subject, detail::default_columns()
193               , compile<karma::domain>(eol));
194         }
195     };
196 
197     // creates columns(c)[] directive generator (c is the number of columns)
198     template <typename T, typename Subject, typename Modifiers>
199     struct make_directive<
200         terminal_ex<tag::columns, fusion::vector1<T> >
201       , Subject, Modifiers
202       , typename enable_if_c<integer_traits<T>::is_integral>::type>
203     {
204         typedef typename
205             result_of::compile<karma::domain, eol_type, Modifiers>::type
206         columns_delimiter_type;
207         typedef columns_generator<
208             Subject, T, columns_delimiter_type
209         > result_type;
210 
211         template <typename Terminal>
operator ()boost::spirit::karma::make_directive212         result_type operator()(Terminal const& term, Subject const& subject
213           , unused_type) const
214         {
215 #if defined(BOOST_SPIRIT_NO_PREDEFINED_TERMINALS)
216             eol_type const eol = eol_type();
217 #endif
218             return result_type(subject, fusion::at_c<0>(term.args)
219               , compile<karma::domain>(eol));
220         }
221     };
222 
223     // creates columns(d)[] directive generator (d is the column delimiter)
224     template <typename T, typename Subject, typename Modifiers>
225     struct make_directive<
226         terminal_ex<tag::columns, fusion::vector1<T> >
227       , Subject, Modifiers
228       , typename enable_if<
229             mpl::and_<
230                 spirit::traits::matches<karma::domain, T>,
231                 mpl::not_<mpl::bool_<integer_traits<T>::is_integral> >
232             >
233         >::type>
234     {
235         typedef typename
236             result_of::compile<karma::domain, T, Modifiers>::type
237         columns_delimiter_type;
238         typedef columns_generator<
239             Subject, detail::default_columns, columns_delimiter_type
240         > result_type;
241 
242         template <typename Terminal>
operator ()boost::spirit::karma::make_directive243         result_type operator()(Terminal const& term, Subject const& subject
244           , unused_type) const
245         {
246             return result_type(subject, detail::default_columns()
247               , compile<karma::domain>(fusion::at_c<0>(term.args)));
248         }
249     };
250 
251     // creates columns(c, d)[] directive generator (c is the number of columns
252     // and d is the column delimiter)
253     template <typename T1, typename T2, typename Subject, typename Modifiers>
254     struct make_directive<
255         terminal_ex<tag::columns, fusion::vector2<T1, T2> >
256       , Subject, Modifiers>
257     {
258         typedef typename
259             result_of::compile<karma::domain, T2, Modifiers>::type
260         columns_delimiter_type;
261         typedef columns_generator<
262             Subject, T1, columns_delimiter_type
263         > result_type;
264 
265         template <typename Terminal>
operator ()boost::spirit::karma::make_directive266         result_type operator()(Terminal const& term, Subject const& subject
267           , unused_type) const
268         {
269             return result_type (subject, fusion::at_c<0>(term.args)
270               , compile<karma::domain>(fusion::at_c<1>(term.args)));
271         }
272     };
273 
274 }}}
275 
276 namespace boost { namespace spirit { namespace traits
277 {
278     ///////////////////////////////////////////////////////////////////////////
279     template <typename Subject, typename T1, typename T2>
280     struct has_semantic_action<karma::columns_generator<Subject, T1, T2> >
281       : unary_has_semantic_action<Subject> {};
282 
283     ///////////////////////////////////////////////////////////////////////////
284     template <typename Subject, typename T1, typename T2, typename Attribute
285       , typename Context, typename Iterator>
286     struct handles_container<
287             karma::columns_generator<Subject, T1, T2>, Attribute
288           , Context, Iterator>
289       : unary_handles_container<Subject, Attribute, Context, Iterator> {};
290 }}}
291 
292 #endif
293