include/AD/rewrite/b_item.h

   1 //////////////////////////////////////////////////////////////////////////////
   2 // NOTICE:
   3 //
   4 // ADLib, Prop and their related set of tools and documentation are in the
   5 // public domain.   The author(s) of this software reserve no copyrights on
   6 // the source code and any code generated using the tools.  You are encouraged
   7 // to use ADLib and Prop to develop software, in both academic and commercial
   8 // settings, and are welcomed to incorporate any part of ADLib and Prop into
   9 // your programs.
  10 //
  11 // Although you are under no obligation to do so, we strongly recommend that
  12 // you give away all software developed using our tools.
  13 //
  14 // We also ask that credit be given to us when ADLib and/or Prop are used in
  15 // your programs, and that this notice be preserved intact in all the source
  16 // code.
  17 //
  18 // This software is still under development and we welcome(read crave for)
  19 // any suggestions and help from the users.
  20 //
  21 // Allen Leung
  22 // 1994
  23 //////////////////////////////////////////////////////////////////////////////
  24
  25 #ifndef BURS_item_h
  26 #define BURS_item_h
  27
  28 #include <iostream>
  29 #include <AD/automata/treegram.h>  // tree grammar
  30 #include <AD/generic/ordering.h>   // hashing functions
  31
  32 //////////////////////////////////////////////////////////////////////////////
  33 //  Items used in the bottom up rewrite system (BURS) generator.
  34 //  An item encodes the following information:
  35 //     (1) A non-terminal,
  36 //     (2) The reduction rule used to arrive at this non-terminal, and
  37 //     (3) The reduction cost.
  38 //////////////////////////////////////////////////////////////////////////////
  39 class BURS_Item {
  40 public:
  41
  42    ///////////////////////////////////////////////////////////////////////////
  43    //  Import some types
  44    ///////////////////////////////////////////////////////////////////////////
  45    typedef TreeGrammar::State       State;
  46    typedef TreeGrammar::Functor     Functor;
  47    typedef TreeGrammar::Arity       Arity;
  48    typedef TreeGrammar::NonTerminal NonTerminal;
  49    typedef TreeGrammar::Cost        Cost;        // reduction cost
  50    typedef TreeGrammar::Rule        Rule;        // reduction rule
  51
  52 public:
  53
  54    ///////////////////////////////////////////////////////////////////////////
  55    //  The internal representation is visible.
  56    ///////////////////////////////////////////////////////////////////////////
  57    Cost cost;   // cost of reduction
  58    Rule rule;   // reduction rule
  59
  60 public:
  61
  62    ///////////////////////////////////////////////////////////////////////////
  63    //  Printing method.
  64    ///////////////////////////////////////////////////////////////////////////
  65    friend std::ostream& operator << (std::ostream&, const BURS_Item&);
  66 };
  67
  68 #endif