lily/music-iterator-ctor.cc

   1 /*
   2   grob-callback.cc --  implement Callback smob.
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "music-iterator-ctor.hh"
  11 #include "ly-smobs.icc"
  12
  13 static long callback_tag;
  14
  15 static
  16 SCM mark_smob (SCM)
  17 {
  18   return SCM_EOL;
  19 }
  20
  21 static int
  22 print_smob (SCM, SCM port, scm_print_state *)
  23 {
  24   scm_puts ("#<encapsulated C++ function>", port);
  25   return 1;
  26 }
  27
  28 static
  29 scm_sizet free_smob (SCM)
  30 {
  31   return 0;
  32 }
  33
  34
  35 void init_cxx_function_smobs()
  36 {
  37   callback_tag = scm_make_smob_type_mfpe ("callback", 0,
  38                                           mark_smob, free_smob,
  39                                           print_smob, 0);
  40 }
  41
  42 SCM
  43 smobify_cxx_function (Cxx_function cb )
  44 {
  45   SCM z;
  46
  47   SCM_NEWCELL(z);
  48   SCM_SETCDR (z, (SCM)cb);
  49   SCM_SETCAR (z, (SCM)callback_tag);
  50
  51   return z;
  52 }
  53
  54
  55 Cxx_function
  56 unsmob_cxx_function (SCM x)
  57 {
  58   if (SCM_CELL_TYPE(x) == callback_tag)
  59     return (Cxx_function) SCM_CELL_WORD_1(x);
  60   else
  61     return 0;
  62 }
  63
  64
  65