lily/music-function.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2004--2011 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "music-function.hh"
  21
  22 #include "music.hh"
  23
  24 static scm_t_bits music_function_tag;
  25
  26 /* Print a textual represenation of the smob to a given port.  */
  27 static int
  28 print_music_function (SCM b, SCM port, scm_print_state *)
  29 {
  30   SCM value = SCM_CELL_OBJECT_1 (b);
  31
  32   scm_puts ("#<Music function ", port);
  33   scm_write (value, port);
  34   scm_puts (">", port);
  35
  36   /* Non-zero means success.  */
  37   return 1;
  38 }
  39
  40 bool
  41 is_music_function (SCM music_function)
  42 {
  43   return (SCM_NIMP (music_function) && SCM_CELL_TYPE (music_function) == music_function_tag);
  44 }
  45
  46 SCM
  47 get_music_function_transform (SCM music_function)
  48 {
  49   if (!is_music_function (music_function))
  50     return SCM_UNDEFINED;
  51
  52   return SCM_CELL_OBJECT_1 (music_function);
  53 }
  54
  55 static void
  56 init_music_function (void)
  57 {
  58   music_function_tag = scm_make_smob_type ("music-function", 0);
  59   scm_set_smob_mark (music_function_tag, scm_markcdr);
  60   scm_set_smob_print (music_function_tag, print_music_function);
  61 }
  62
  63 SCM
  64 make_music_function (SCM signature, SCM func)
  65 {
  66   scm_set_object_property_x (func, ly_symbol2scm ("music-function-signature"),
  67                              signature);
  68
  69   SCM_RETURN_NEWSMOB (music_function_tag, func);
  70 }
  71
  72 ADD_SCM_INIT_FUNC (music_function_tag, init_music_function);
  73