lily/nested-property.cc

   1 #include "context.hh"
   2 #include "grob.hh"
   3
   4 SCM
   5 evict_from_alist (SCM symbol,
   6                   SCM alist,
   7                   SCM alist_end)
   8 {
   9   SCM new_alist = SCM_EOL;
  10   SCM *tail = &new_alist;
  11
  12   while (alist != alist_end)
  13     {
  14       if (ly_is_equal (scm_caar (alist), symbol))
  15         {
  16           alist = scm_cdr (alist);
  17           break;
  18         }
  19
  20       *tail = scm_cons (scm_car (alist), SCM_EOL);
  21       tail = SCM_CDRLOC (*tail);
  22       alist = scm_cdr (alist);
  23     }
  24
  25   *tail = alist;
  26   return new_alist;
  27 }
  28
  29 /*
  30   PROP_PATH should be big-to-small ordering
  31  */
  32 SCM
  33 nested_property_alist (SCM alist, SCM prop_path, SCM value)
  34 {
  35   SCM new_value = SCM_BOOL_F;
  36   if (scm_is_pair (scm_cdr (prop_path)))
  37     {
  38       SCM sub_alist = ly_assoc_get (scm_car (prop_path), alist, SCM_EOL);
  39       new_value = nested_property_alist (sub_alist, scm_cdr (prop_path), value);
  40     }
  41   else
  42     {
  43         new_value = value;
  44     }
  45
  46   return scm_acons (scm_car (prop_path), new_value, alist);
  47 }
  48
  49 SCM
  50 nested_property_revert_alist (SCM alist, SCM prop_path)
  51 {
  52   SCM new_sub_alist = SCM_EOL;
  53   SCM sym = scm_car (prop_path);
  54   if (scm_is_pair (scm_cdr (prop_path)))
  55     {
  56       SCM sub_alist = ly_assoc_get (sym, alist, SCM_EOL);
  57       new_sub_alist = nested_property_revert_alist (sub_alist, scm_cdr (prop_path));
  58     }
  59   else
  60     {
  61       new_sub_alist = evict_from_alist (sym, alist, SCM_EOL);
  62     }
  63
  64   return scm_acons (sym, new_sub_alist, alist);
  65 }
  66
  67
  68 void
  69 set_nested_property (Grob *me, SCM big_to_small, SCM value)
  70 {
  71   SCM alist = me->get_property (scm_car (big_to_small));
  72
  73   alist = nested_property_alist (alist, scm_cdr (big_to_small), value);
  74
  75   me->set_property (scm_car (big_to_small),
  76                     alist);
  77 }
  78