lily/music-function.cc

   1 /*
   2   music-function.cc -- implement music_function
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2004--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "music-function.hh"
  10
  11 #include "music.hh"
  12
  13 static scm_t_bits music_function_tag;
  14
  15 /* Print a textual represenation of the smob to a given port.  */
  16 static int
  17 print_music_function (SCM b, SCM port, scm_print_state *)
  18 {
  19   SCM value = SCM_CELL_OBJECT_1 (b);
  20
  21   scm_puts ("#<Music function ", port);
  22   scm_write (value, port);
  23   scm_puts (">", port);
  24
  25   /* Non-zero means success.  */
  26   return 1;
  27 }
  28
  29 bool
  30 is_music_function (SCM music_function)
  31 {
  32   return (SCM_NIMP (music_function) && SCM_CELL_TYPE (music_function) == music_function_tag);
  33 }
  34
  35 SCM
  36 get_music_function_transform (SCM music_function)
  37 {
  38   if (!is_music_function (music_function))
  39     return SCM_UNDEFINED;
  40
  41   return SCM_CELL_OBJECT_1 (music_function);
  42 }
  43
  44 static void
  45 init_music_function (void)
  46 {
  47   music_function_tag = scm_make_smob_type ("music-function", 0);
  48   scm_set_smob_mark (music_function_tag, scm_markcdr);
  49   scm_set_smob_print (music_function_tag, print_music_function);
  50 }
  51
  52 SCM
  53 make_music_function (SCM signature, SCM func)
  54 {
  55   scm_set_object_property_x (func, ly_symbol2scm ("music-function-signature"),
  56                              signature);
  57
  58   SCM_RETURN_NEWSMOB (music_function_tag, func);
  59 }
  60
  61 ADD_SCM_INIT_FUNC (music_function_tag, init_music_function);
  62