ch18ex08.pro

来自「prolog,人工智能推理程序,运行环境prolog」· PRO 代码 · 共 42 行

/*
   Turbo Prolog 2.0 Chapter 18, Example Program 8
   
   Copyright (c) 1986, 88 by Borland International, Inc
   
*/
   
domains
   key = cr; esc; break; tab; btab; del; bdel; ins; end; home;
   fkey(integer); up_arrow; down_arrow; left_arrow; right_arrow;
   char(CHAR); other

predicates
   readkey(key)
   key_code(key, char, integer)
   key_code2(key, integer)

/*
goal
   clearwindow,
   write("Keyboard test. Press a key!"),
   readkey(Key), nl,
   write("The ", Key, "-key was pressed").
*/

clauses
   readkey(Key) :-
      readchar(T), char_int(T, Val), key_code(Key, T, Val).

   key_code(Key, _, 0) :- readchar(T), char_int(T, Val),
   key_code2(Key, Val), !.
   key_code(break, _, 3) :- !.        key_code(bdel, _, 8) :- !.
   key_code(tab, _, 10) :- !.         key_code(cr, _, 13) :- !.
   key_code(esc, _, 27) :- !.         key_code(char(T), T, _).
   key_code2(btab, 15) :- !.          key_code2(home, 71) :- !.
   key_code2(up_arrow, 72) :- !.      key_code2(left_arrow, 75):- !.
   key_code2(right_arrow, 77) :- !.   key_code2(end, 79) :- !.
   key_code2(down_arrow, 80) :- !.    key_code2(ins, 82) :- !.
   key_code2(del, 83) :- !.
   key_code2(fkey(N), V) :- V>58, V<70, N=V-58, !.
   key_code2(other, _).