include/AD/automata/first_k.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 free 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 any suggestions
  19 // and help from the users.
  20 //
  21 // Allen Leung
  22 // 1994
  23 //////////////////////////////////////////////////////////////////////////////
  24
  25 #ifndef first_set_with_k_lookaheads_computation_h
  26 #define first_set_with_k_lookaheads_computation_h
  27
  28 #include <AD/automata/follow.h>
  29
  30 class FirstSet_k : public FollowSet {
  31
  32    FirstSet_k(const FirstSet_k&);       // no copy constructor
  33    void operator = (const FirstSet_k&); // no assignment
  34
  35 public:
  36
  37    ///////////////////////////////////////////////////////////////////////////
  38    //  Import some types
  39    ///////////////////////////////////////////////////////////////////////////
  40    typedef FollowSet             Super;
  41    typedef Super::Symbol         Symbol;
  42    typedef Super::Terminal       Terminal;
  43    typedef Super::NonTerminal    NonTerminal;
  44    typedef Super::Production     Production;
  45    typedef Super::ProductionList ProductionList;
  46
  47 protected:
  48
  49    ///////////////////////////////////////////////////////////////////////////
  50    //  Internals
  51    ///////////////////////////////////////////////////////////////////////////
  52    int K;     // the current number of lookaheads
  53    int max_K; // the maximum number of lookaheads
  54    BitSet *** first_set_k;
  55
  56 public:
  57
  58    ///////////////////////////////////////////////////////////////////////////
  59    //  Constructor and destructors
  60    ///////////////////////////////////////////////////////////////////////////
  61    FirstSet_k(const Grammar&, Mem&);
  62   ~FirstSet_k();
  63
  64    ///////////////////////////////////////////////////////////////////////////
  65    //  Compute the sets
  66    ///////////////////////////////////////////////////////////////////////////
  67    virtual void compute_sets(int k, int max_k);
  68
  69    ///////////////////////////////////////////////////////////////////////////
  70    //  Selectors
  71    ///////////////////////////////////////////////////////////////////////////
  72    inline int k()     const { return K; }
  73    inline int max_k() const { return max_K; }
  74    inline const BitSet& first (int k, NonTerminal A) const
  75       { return *first_set_k[k][A]; }
  76
  77    Bool first (int k, BitSet&, Production)        const;
  78    Bool first (int k, BitSet&, Production, Bool&) const;
  79 };
  80
  81 #endif