lily/music-constructor.cc

   1 /*
   2   music-constructor.cc --  implement Music_constructor
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2001--2004  Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include <map>                  // UGH.
  11 #include <assert.h>
  12
  13 #include "warn.hh"
  14 #include "music-constructor.hh"
  15
  16 typedef Music* (*Music_ctor) ();
  17
  18 static std::map<String,Music_ctor> *ctors_map_;
  19
  20 void
  21 add_music_ctor (String s,  Music_ctor c)
  22 {
  23   if (!ctors_map_)
  24     ctors_map_ = new std::map<String, Music_ctor>;
  25
  26  (*ctors_map_)[s] = c;
  27 }
  28
  29
  30 Music_ctor
  31 get_music_ctor (String s)
  32 {
  33   if (ctors_map_->find (s) == ctors_map_->end ())
  34     return 0;
  35
  36   return (* ctors_map_)[s];
  37 }
  38
  39 Music*
  40 make_music (String s)
  41 {
  42   Music_ctor c = get_music_ctor (s);
  43   if (!c)
  44     programming_error (String ("No constructor for music: ") + s);
  45   assert (c);
  46
  47   return (*c) ();
  48 }
  49