lisp_library.pl

   1 /*******************************************************************
   2  *
   3  * A Lisp compiler, written in Prolog
   4  *
   5  * (lisp_library.pl)
   6  *
   7  * (c) Neil Smith, 2001
   8  *
   9  * This program provides some built-in functionality for the
  10  * Lisp compiler.  It requires that the file lisp_compiler.pl has
  11  * already been successfully compiled.
  12  *
  13  * Definitions in this file are given in the Lisp-like syntax
  14  * read by this compiler.
  15  *
  16  *******************************************************************/
  17
  18
  19 second(l) <<==
  20         first(rest(l)).
  21
  22 third(l) <<==
  23         first(rest(rest(l))).
  24
  25
  26 % We don't support &rest parameters yet, so we need a different
  27 % definition of list for every different number of arguments
  28
  29 list_1(a) <<==
  30         cons(a, nil).
  31
  32 list_2(a, b) <<==
  33         cons(a, list_1(b)).
  34
  35 list_3(a, b, c) <<==
  36         cons(a, list_2(b,c)).
  37
  38
  39 lisp_append(l1, l2) <<==
  40         if( null(l1),
  41             l2,
  42             cons( first(l1),
  43                   lisp_append(rest(l1),
  44                               l2))).
  45
  46
  47 mapcar(func, l) <<==
  48         if( null(l),
  49                 nil,
  50                 cons( lisp_apply(func, list_1(first(l))),
  51                         mapcar(func, rest(l)))).
  52
  53