lily/stencil-expression.cc

   1 /*
   2   stencil-expression.cc -- keep track of which expressions are valid
   3   stencil exps.
   4
   5   source file of the GNU LilyPond music typesetter
   6
   7   (c) 2005--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
   8 */
   9
  10 #include "stencil.hh"
  11
  12 static SCM heads;
  13
  14 void register_stencil_head (SCM symbol)
  15 {
  16   if (!heads)
  17     heads = scm_permanent_object (scm_cons (SCM_EOL, SCM_EOL));
  18
  19   scm_set_object_property_x (symbol, ly_symbol2scm ("stencil-head?"), SCM_BOOL_T);
  20   scm_set_cdr_x (heads,  scm_cons (symbol, scm_cdr (heads)));
  21 }
  22
  23 bool
  24 is_stencil_head (SCM symbol)
  25 {
  26   return scm_object_property (symbol, ly_symbol2scm ("stencil-head?"))
  27     == SCM_BOOL_T;
  28 }
  29
  30 SCM
  31 all_stencil_heads ()
  32 {
  33   return scm_cdr (heads);
  34 }
  35