ch15ex02.pro

prolog,人工智能推理程序,运行环境prolog

/*
   Turbo Prolog 2.0 Chapter 15, Example Program 2
   
   Copyright (c) 1986, 88 by Borland International, Inc
   
*/
    
domains
   my_dom = f(string)
   db_selector = my_dba

predicates
   write_dba(integer)
   read_dba
   rd(Ref)
   count_dba(integer)
   count(Ref, integer, integer)
   replace_dba
   replace(Ref)
   double_dba
   double(Ref)
   half_dba
   half(Ref)
   mixture

clauses
   write_dba(0) :- !.
   write_dba(N) :-
      chain_inserta(my_dba, my_chain, my_dom, f("Prolog system"), _),
      chain_insertz(my_dba, my_chain, my_dom, f("Prolog Compiler"), _),
      N1=N-1,
      write_dba(N1).

   read_dba :-
      db_chains(my_dba, Chain),
      chain_terms(my_dba, Chain, my_dom, Term, Ref),
      write("\nRef=", Ref, ", Term=", Term),
      fail.
   read_dba :-
      db_chains(my_dba, Chain),
      chain_first(my_dba, Chain, Ref),
      rd(Ref),
      fail.
   read_dba.

   rd(Ref) :-
      ref_term(my_dba, my_dom, Ref, Term), nl, write(Term), fail.
   rd(Ref) :-
      chain_next(my_dba, Ref, Next), !, rd(Next).
   rd(_).

   replace_dba :-
      chain_first(my_dba, my_chain, Ref),
      replace(Ref).

   replace(Ref) :-
      term_replace(my_dba, my_dom, Ref, f("Prolog Toolbox")),
      chain_next(my_dba, Ref, NN),
      chain_next(my_dba, NN, Next), !,
      replace(Next).
   replace(_).

   half_dba :-
      chain_last(my_dba, my_chain, Ref),
      half(Ref).

   half(Ref) :-
      chain_prev(my_dba, Ref, PP),
      chain_prev(my_dba, PP, Prev), !,
      term_delete(my_dba, my_chain, Ref),
      half(Prev).
   half(_).

   double_dba :-
      chain_first(my_dba, my_chain, Ref),
      double(Ref).

   double(Ref) :-
      chain_next(my_dba, Ref, Next), !,
      chain_insertafter(my_dba, my_chain, my_dom, Ref,f("Programmers Guide"), _),
      double(Next).
   double(_).

   count_dba(N) :-
      chain_first(my_dba, my_chain, Ref),
      count(Ref, 1, N).

   count(Ref, N, N2) :-
      chain_next(my_dba, Ref, Next), !,
      N1=N+1,
      count(Next, N1, N2).
   count(_, N, N).

   mixture :-
      write("\nReplace every second term:"),
      replace_dba,
      write("\nDouble the number of terms:"),
      double_dba,
      write("\nErase every second term:"),
      half_dba,
      write("\nUse ref_term for all terms:"),
      read_dba,
      count_dba(N),
      write("\nThere are now ", N, " terms in the database"),
      db_statistics(my_dba, NoOfTerms, MemSize, DbaSize, FreSize),
      writef("\nNoOfTerms=%, MemSize=%, DbaSize=%, FreeSize=%", NoOfTerms, MemSize,DbaSize,FreSize).

goal
   write("\n\n\n\tTEST OF DATABASE SYSTEM\n\t***********************\n\n"),
   time(H1, M1, S1, D1),
   db_create(my_dba, "dd.dat", in_memory),
   write("\n\nWrite some terms in the database:"),
   write_dba(50),
   read_dba,
   mixture,

   write("\n\n\nCopy to file"),
   db_copy(my_dba, "dd.dat", in_file),
   db_close(my_dba),  db_delete("dd.dat", in_memory),
   db_open(my_dba, "dd.dat", in_file),
   mixture,
   db_close(my_dba),

   write("\n\n\nOpen the database on file"),
   db_open(my_dba, "dd.dat", in_file),
   mixture,
   db_close(my_dba),

   time(H2, M2, S2, D2),
   Time = (D2-D1)+100.0*((S2-S1)+60.0*((M2-M1)+ 60.0*(H2-H1))),
   write("\n\nTime = ", Time, "/100 Sec" ), nl.