Console/Parse.ih

   1 // $Id$
   2 //
   3 // Copyright (C) 2008
   4 // Fraunhofer Institute for Open Communication Systems (FOKUS)
   5 // Competence Center NETwork research (NET), St. Augustin, GERMANY
   6 //     Stefan Bund <g0dil@berlios.de>
   7 //
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 2 of the License, or
  11 // (at your option) any later version.
  12 //
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17 //
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the
  20 // Free Software Foundation, Inc.,
  21 // 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  22
  23 /** \file
  24     \brief Parse internal header */
  25
  26 #ifndef IH_Parse_
  27 #define IH_Parse_ 1
  28
  29 // Custom includes
  30 #include <vector>
  31 #include <boost/regex.hpp>
  32 #include <boost/spirit.hpp>
  33 #include <boost/spirit/utility/grammar_def.hpp>
  34 #include <boost/spirit/actor.hpp>
  35 #include <boost/bind.hpp>
  36 #include <boost/function.hpp>
  37 #include <boost/ref.hpp>
  38
  39 ///////////////////////////////ih.p////////////////////////////////////////
  40
  41 namespace senf {
  42 namespace console {
  43 namespace detail {
  44
  45 #ifndef DOXYGEN
  46
  47     ///////////////////////////////////////////////////////////////////////////
  48     // append_a
  49
  50     struct append_action
  51     {
  52         template <class T, class Value>
  53         void act(T & ref, Value const & value) const
  54             { ref += T(1, value); }
  55
  56         template <class T, class Iterator>
  57         void act(T & ref, Iterator const & f, Iterator const & l) const
  58             { ref += T(f,l); }
  59     };
  60
  61     template <class T>
  62     inline boost::spirit::ref_value_actor<T, append_action>
  63     append_a(T & ref)
  64     { return boost::spirit::ref_value_actor<T, append_action>(ref); }
  65
  66     template <class T, class Value>
  67     inline boost::spirit::ref_const_ref_actor<T, Value, append_action>
  68     append_a(T & ref, Value const & value)
  69     { return boost::spirit::ref_const_ref_actor<T, Value, append_action>(ref, value); }
  70
  71     ///////////////////////////////////////////////////////////////////////////
  72     // Grammar
  73
  74     template <class ParseDispatcher>
  75     struct CommandGrammar : boost::spirit::grammar<CommandGrammar<ParseDispatcher> >
  76     {
  77         ///////////////////////////////////////////////////////////////////////////
  78         // Start rules
  79
  80         enum { CommandParser, SkipParser };
  81
  82         ///////////////////////////////////////////////////////////////////////////
  83         // The parse context (variables needed while parsing)
  84
  85         struct Context {
  86             std::string str;
  87             std::vector<std::string> path;
  88             char ch;
  89         };
  90
  91         Context & context;
  92
  93         ///////////////////////////////////////////////////////////////////////////
  94         // Dispatching semantic actions
  95
  96         ParseDispatcher & dispatcher;
  97
  98         struct Dispatch_actor
  99         {
 100             Dispatch_actor(boost::function<void ()> fn_) : fn (fn_) {}
 101
 102             template <class Value>
 103             void operator()(Value const & value) const
 104                 { fn(); }
 105
 106             template <class Iterator>
 107             void operator()(Iterator const & f, Iterator const & l) const
 108                 { fn(); }
 109
 110             boost::function<void ()> fn;
 111         };
 112
 113         template <class Callback>
 114         Dispatch_actor dispatch(Callback cb) const
 115             { return Dispatch_actor(boost::bind(cb, boost::ref(dispatcher))); }
 116
 117         template <class Callback, class Arg>
 118         Dispatch_actor dispatch(Callback cb, Arg const & arg) const
 119             { return Dispatch_actor(boost::bind(cb, boost::ref(dispatcher), arg)); }
 120
 121         ///////////////////////////////////////////////////////////////////////////
 122
 123         CommandGrammar(ParseDispatcher & d, Context & c)
 124             : context(c), dispatcher(d) {}
 125
 126         template <class Scanner>
 127         struct definition
 128             : public boost::spirit::grammar_def< boost::spirit::rule<Scanner>,
 129                                                  boost::spirit::rule<Scanner> >
 130         {
 131             boost::spirit::rule<Scanner> command, path, argument, word, string, hexstring, token,
 132                 punctuation, hexbyte, balanced_tokens, simple_argument, complex_argument, builtin,
 133                 skip, commands, block, statement, relpath, abspath;
 134             boost::spirit::chset<> special_p, punctuation_p, space_p, invalid_p, word_p;
 135             boost::spirit::distinct_parser<> keyword_p;
 136
 137             definition(CommandGrammar const & self) :
 138
 139                 // Characters with a special meaning within the parser
 140                 special_p ("/(){};"),
 141
 142                 // Characters which are returned as punctuation tokens
 143                 punctuation_p (",="),
 144
 145                 // Whitespace characters
 146                 space_p (" \t\n\r"),
 147
 148                 // Invalid characters: All chars below \x20 (space) which are not space_p
 149                 // (don't put a \0 in the chset<> argument *string* ...)
 150                 invalid_p (
 151                     boost::spirit::chset<>('\0') | boost::spirit::chset<>("\x01-\x20") - space_p ),
 152
 153                 // Valid word characters
 154                 word_p (
 155                     boost::spirit::anychar_p - special_p - punctuation_p - space_p - invalid_p),
 156
 157                 // Keywords must not be followed by a word char or '/'
 158                 keyword_p ( word_p | boost::spirit::ch_p('/') )
 159
 160             {
 161                 using namespace boost::spirit;
 162                 typedef ParseDispatcher PD;
 163
 164                 ///////////////////////////////////////////////////////////////////
 165                 // Spirit grammar
 166                 //
 167                 // Syntax summary:
 168                 // This is EBNF with some minor tweaks to accommodate C++ syntax
 169                 //
 170                 //   * and +    like EBNF but they precede their argument
 171                 //   >>         is followed by
 172                 //   !          optional
 173                 //   a % b      match any number of a's separated by b
 174                 //   a - b      match a but not b
 175                 //
 176                 // Beside this, we use some special parsers (ch_p, eps_p, confix_p, lex_escape_ch_p,
 177                 // keyword_p, comment_p) and directives (lexeme_d), however, the parser should be
 178                 // quite readable.
 179                 //
 180                 //   ch_p             match character
 181                 //   eps_p            always matches nothing (to attach unconditional actions)
 182                 //   confix_p(a,b,c)  match b, preceded by a and terminated by c. Used to parse
 183                 //                    string literals and comments
 184                 //   lex_escape_ch_p  match a lex style escape char. This is like a C++ style
 185                 //                    literal string escape char, however \x will be replaced by 'x'
 186                 //                    for any char 'x' if it has no special meaning.
 187                 //   keyword_p        match a delimited keyword
 188                 //   comment_p(a,b)   match comment starting with a and terminated with b. b
 189                 //                    defaults to end-of-line
 190                 //
 191                 //   lexeme_d         don't skip whitespace (as defined by the skip parser)
 192                 //
 193                 // Aligned to the right at column 50 are semantic actions.
 194                 //
 195                 // For clarity, I have used 'ch_p' explicitly throughout even though it is optional
 196                 // in most cases.
 197                 //
 198                 // More info is in the Boost.Spirit documentation
 199
 200                 commands
 201                     =  * command
 202                     ;
 203
 204                 command
 205                     =    builtin >> (ch_p(';') | end_p)
 206                     |    path  >> ( block | statement )
 207                     |    ch_p(';') // Ignore empty commands
 208                     ;
 209
 210                 builtin
 211                     =    keyword_p("cd")
 212                       >> path
 213                       >> eps_p                    [ self.dispatch(&PD::builtin_cd,
 214                                                                   boost::ref(self.context.path)) ]
 215                     |    keyword_p("ls")
 216                       >> ! path
 217                       >> eps_p                    [ self.dispatch(&PD::builtin_ls,
 218                                                                   boost::ref(self.context.path)) ]
 219                     |    keyword_p("exit")        [ self.dispatch(&PD::builtin_exit) ]
 220
 221                     |    keyword_p("help")
 222                       >> ! path
 223                       >> eps_p                    [ self.dispatch(&PD::builtin_help,
 224                                                                   boost::ref(self.context.path)) ]
 225                     ;
 226
 227                 block
 228                     =    ch_p('{')                [ self.dispatch(&PD::pushDirectory,
 229                                                                   boost::ref(self.context.path)) ]
 230                       >> * command
 231                       >> ch_p('}')                [ self.dispatch(&PD::popDirectory) ]
 232                     ;
 233
 234                 statement
 235                     = eps_p                       [ self.dispatch(&PD::beginCommand,
 236                                                                   boost::ref(self.context.path)) ]
 237                       >> * argument
 238                       >> (ch_p(';') | end_p)
 239                       >> eps_p                    [ self.dispatch(&PD::endCommand) ]
 240                     ;
 241
 242                 argument
 243                     =    simple_argument          [ self.dispatch(&PD::pushArgument,
 244                                                                   boost::ref(self.context.str)) ]
 245                     |    complex_argument
 246                     ;
 247
 248                 simple_argument         // All these return their value in context.str
 249                     =    string
 250                     |    hexstring
 251                     |    word
 252                     ;
 253
 254                 complex_argument        // Argument consists of multiple tokens
 255                     =    ch_p('(')                [ self.dispatch(&PD::openGroup) ]
 256                       >> * token
 257                       >> ch_p(')')                [ self.dispatch(&PD::closeGroup) ]
 258                     ;
 259
 260                 string                  // Returns value in context.str
 261                     =    eps_p                    [ clear_a(self.context.str) ]
 262                       >> lexeme_d
 263                          [
 264                              ch_p('"')
 265                           >> * ( ( lex_escape_ch_p[ assign_a(self.context.ch) ]
 266                                    - '"'
 267                                  )                [ append_a(self.context.str,
 268                                                              self.context.ch) ]
 269                                )
 270                           >> ch_p('"')
 271                          ]
 272                     ;
 273
 274                 hexstring               // Returns value in context.str
 275                     =    eps_p                    [ clear_a(self.context.str) ]
 276                       >> confix_p( "x\"", * hexbyte, '"' )
 277                     ;
 278
 279                 path                    // Returns value in context.path
 280                     =    eps_p                    [ clear_a(self.context.path) ]
 281                       >> relpath | abspath
 282                     ;
 283
 284                 relpath
 285                     =    (   word                 [ push_back_a(self.context.path) ]
 286                            % ch_p('/') )
 287                       >> ( ! ch_p('/')            [ push_back_a(self.context.path,"") ] )
 288                     ;
 289
 290                 abspath
 291                     =    ch_p('/')                [ push_back_a(self.context.path, "") ]
 292                       >> ( relpath
 293                          | eps_p                  [ push_back_a(self.context.path, "") ] )
 294                     ;
 295
 296                 balanced_tokens
 297                     =    ch_p('(')                [ self.dispatch(&PD::pushPunctuation, "(") ]
 298                       >> * token
 299                       >> ch_p(')')                [ self.dispatch(&PD::pushPunctuation, ")") ]
 300                     ;
 301
 302                 token
 303                     =    simple_argument          [ self.dispatch(&PD::pushWord,
 304                                                                   boost::ref(self.context.str)) ]
 305                     |    punctuation              [ self.dispatch(&PD::pushPunctuation,
 306                                                                   boost::ref(self.context.str)) ]
 307                     |    balanced_tokens
 308                     ;
 309
 310                 punctuation             // Returns value in context.str
 311                     =    punctuation_p            [ assign_a(self.context.str) ]
 312                     ;
 313
 314                 word                    // Returns value in context.str
 315                     =    lexeme_d[ + word_p ]     [ assign_a(self.context.str) ]
 316                     ;
 317
 318                 hexbyte
 319                     =    uint_parser<char, 16, 2, 2>()
 320                                                   [ append_a(self.context.str) ]
 321                     ;
 322
 323                 skip
 324                     =    space_p | comment_p('#')
 325                     ;
 326
 327                 ///////////////////////////////////////////////////////////////////
 328
 329                 start_parsers(
 330                     commands,           // CommandParser
 331                     skip                // SkipParser
 332                 );
 333
 334                 BOOST_SPIRIT_DEBUG_TRACE_RULE(command,1);
 335                 BOOST_SPIRIT_DEBUG_TRACE_RULE(path,1);
 336                 BOOST_SPIRIT_DEBUG_TRACE_RULE(argument,1);
 337                 BOOST_SPIRIT_DEBUG_TRACE_RULE(word,1);
 338                 BOOST_SPIRIT_DEBUG_TRACE_RULE(string,1);
 339                 BOOST_SPIRIT_DEBUG_TRACE_RULE(hexstring,1);
 340                 BOOST_SPIRIT_DEBUG_TRACE_RULE(token,1);
 341                 BOOST_SPIRIT_DEBUG_TRACE_RULE(punctuation,1);
 342                 BOOST_SPIRIT_DEBUG_TRACE_RULE(hexbyte,1);
 343                 BOOST_SPIRIT_DEBUG_TRACE_RULE(balanced_tokens,1);
 344                 BOOST_SPIRIT_DEBUG_TRACE_RULE(simple_argument,1);
 345                 BOOST_SPIRIT_DEBUG_TRACE_RULE(complex_argument,1);
 346                 BOOST_SPIRIT_DEBUG_TRACE_RULE(builtin,1);
 347                 BOOST_SPIRIT_DEBUG_TRACE_RULE(commands,1);
 348                 BOOST_SPIRIT_DEBUG_TRACE_RULE(block,1);
 349                 BOOST_SPIRIT_DEBUG_TRACE_RULE(statement,1);
 350                 BOOST_SPIRIT_DEBUG_TRACE_RULE(relpath,1);
 351                 BOOST_SPIRIT_DEBUG_TRACE_RULE(abspath,1);
 352             }
 353         };
 354     };
 355
 356
 357
 358 #endif
 359
 360 }}}
 361
 362 ///////////////////////////////ih.e////////////////////////////////////////
 363 #endif
 364
 365 \f
 366 // Local Variables:
 367 // mode: c++
 368 // fill-column: 100
 369 // comment-column: 40
 370 // c-file-style: "senf"
 371 // indent-tabs-mode: nil
 372 // ispell-local-dictionary: "american"
 373 // compile-command: "scons -u test"
 374 // End: