lily/score-element.cc

   1 /*
   2   score-elem.cc -- implement Score_element
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--2000 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9
  10 #include <string.h>
  11 #include <math.h>
  12
  13 #include "input-smob.hh"
  14 #include "libc-extension.hh"
  15 #include "group-interface.hh"
  16 #include "misc.hh"
  17 #include "paper-score.hh"
  18 #include "paper-def.hh"
  19 #include "lookup.hh"
  20 #include "molecule.hh"
  21 #include "score-element.hh"
  22 #include "debug.hh"
  23 #include "spanner.hh"
  24 #include "line-of-score.hh"
  25 #include "item.hh"
  26 #include "paper-column.hh"
  27 #include "molecule.hh"
  28 #include "misc.hh"
  29 #include "paper-outputter.hh"
  30 #include "dimension-cache.hh"
  31 #include "side-position-interface.hh"
  32 #include "item.hh"
  33
  34 /*
  35 TODO:
  36
  37 remove dynamic_cast<Spanner,Item> and put this code into respective
  38   subclass.
  39 */
  40
  41
  42 #define INFINITY_MSG "Infinity or NaN encountered"
  43
  44 Score_element::Score_element(SCM basicprops)
  45 {
  46   set_extent_callback (molecule_extent, X_AXIS);
  47   set_extent_callback (molecule_extent, Y_AXIS);
  48
  49   pscore_l_=0;
  50   lookup_l_ =0;
  51   status_i_ = 0;
  52   self_scm_ = SCM_EOL;
  53   original_l_ = 0;
  54   immutable_property_alist_ =  basicprops;
  55   mutable_property_alist_ = SCM_EOL;
  56
  57   smobify_self ();
  58   set_elt_property ("dependencies", SCM_EOL);
  59
  60   if (get_elt_property ("interfaces") == SCM_UNDEFINED)
  61     set_elt_property ("interfaces", SCM_EOL);
  62 }
  63
  64
  65 Score_element::Score_element (Score_element const&s)
  66    : dim_cache_ (s.dim_cache_)
  67 {
  68   self_scm_ = SCM_EOL;
  69   original_l_ =(Score_element*) &s;
  70   immutable_property_alist_ = s.immutable_property_alist_;
  71   mutable_property_alist_ = SCM_EOL;
  72
  73   status_i_ = s.status_i_;
  74   lookup_l_ = s.lookup_l_;
  75   pscore_l_ = s.pscore_l_;
  76
  77   smobify_self ();
  78 }
  79
  80 Score_element::~Score_element()
  81 {
  82   /*
  83     do nothing scm-ish and no unprotecting here.
  84    */
  85 }
  86
  87
  88 SCM
  89 Score_element::get_elt_property (const char *nm) const
  90 {
  91   SCM sym = ly_symbol2scm (nm);
  92   return get_elt_property (sym);
  93 }
  94
  95 SCM
  96 Score_element::get_elt_property (SCM sym) const
  97 {
  98   SCM s = scm_sloppy_assq(sym, mutable_property_alist_);
  99   if (s != SCM_BOOL_F)
 100     return gh_cdr (s);
 101
 102   s = scm_sloppy_assq (sym, immutable_property_alist_);
 103   return (s == SCM_BOOL_F) ? SCM_EOL : gh_cdr (s);
 104 }
 105
 106 /*
 107   Remove the value associated with KEY, and return it. The result is
 108   that a next call will yield SCM_UNDEFINED (and not the underlying
 109   `basic' property.
 110 */
 111 SCM
 112 Score_element::remove_elt_property (const char* key)
 113 {
 114   SCM val = get_elt_property (key);
 115   if (val != SCM_EOL)
 116     set_elt_property (key, SCM_EOL);
 117   return val;
 118 }
 119
 120 void
 121 Score_element::set_elt_property (const char* k, SCM v)
 122 {
 123   SCM s = ly_symbol2scm (k);
 124   set_elt_property (s, v);
 125 }
 126
 127 /*
 128   Puts the k, v in the immutable_property_alist_, which is convenient for
 129   storing variables that are needed during the breaking process. (eg.
 130   Line_of_score::rank : int )
 131  */
 132 void
 133 Score_element::set_immutable_elt_property (const char*k, SCM v)
 134 {
 135   SCM s = ly_symbol2scm (k);
 136   set_immutable_elt_property (s, v);
 137 }
 138
 139 void
 140 Score_element::set_immutable_elt_property (SCM s, SCM v)
 141 {
 142   immutable_property_alist_ = gh_cons (gh_cons (s,v), mutable_property_alist_);
 143   mutable_property_alist_ = scm_assq_remove_x (mutable_property_alist_, s);
 144 }
 145 void
 146 Score_element::set_elt_property (SCM s, SCM v)
 147 {
 148   mutable_property_alist_ = scm_assq_set_x (mutable_property_alist_, s, v);
 149 }
 150
 151
 152 Interval
 153 Score_element::molecule_extent (Score_element *s, Axis a)
 154 {
 155   Molecule m = s->get_molecule ();
 156   return m.extent(a);
 157 }
 158
 159 Interval
 160 Score_element::preset_extent (Score_element  *s , Axis a)
 161 {
 162   SCM ext = s->get_elt_property ((a == X_AXIS)
 163                                  ? "extent-X"
 164                                  : "extent-Y");
 165
 166   if (gh_pair_p (ext))
 167     {
 168       Real l = gh_scm2double (gh_car (ext));
 169       Real r = gh_scm2double (gh_cdr (ext));
 170       l *= s->paper_l ()->get_var ("staffspace");
 171       r *= s->paper_l ()->get_var ("staffspace");
 172       return Interval (l, r);
 173     }
 174
 175   return Interval ();
 176 }
 177
 178
 179
 180 Paper_def*
 181 Score_element::paper_l ()  const
 182 {
 183  return pscore_l_ ? pscore_l_->paper_l_ : 0;
 184 }
 185
 186 Lookup const *
 187 Score_element::lookup_l () const
 188 {
 189   if (!lookup_l_)
 190     {
 191       Score_element * urg = (Score_element*)this;
 192       SCM sz = urg->remove_elt_property ("fontsize");
 193       int i = (gh_number_p (sz))
 194         ? gh_scm2int  (sz)
 195         : 0;
 196
 197       urg->lookup_l_ =  (Lookup*)pscore_l_->paper_l_->lookup_l (i);
 198     }
 199   return lookup_l_;
 200 }
 201
 202 void
 203 Score_element::add_processing()
 204 {
 205   assert (status_i_ >=0);
 206   if (status_i_)
 207     return;
 208   status_i_ ++;
 209
 210   do_add_processing();
 211 }
 212
 213 void
 214 Score_element::calculate_dependencies (int final, int busy, SCM funcname)
 215 {
 216   assert (status_i_ >=0);
 217
 218   if (status_i_ >= final)
 219     return;
 220
 221   if (status_i_== busy)
 222     {
 223       programming_error ("Element is busy, come back later");
 224       return;
 225     }
 226
 227   status_i_= busy;
 228
 229   for (SCM d=  get_elt_property ("dependencies"); gh_pair_p (d); d = gh_cdr (d))
 230     {
 231       unsmob_element (gh_car (d))
 232         ->calculate_dependencies (final, busy, funcname);
 233     }
 234
 235   // ughugh.
 236   String s = ly_symbol2string (funcname);
 237   SCM proc = get_elt_property (s.ch_C());
 238   if (gh_procedure_p (proc))
 239     gh_call1 (proc, this->self_scm_);
 240
 241   status_i_= final;
 242
 243 }
 244
 245 Molecule
 246 Score_element::get_molecule ()  const
 247 {
 248   SCM proc = get_elt_property ("molecule-callback");
 249
 250   SCM mol = SCM_EOL;
 251   if (gh_procedure_p (proc))
 252     mol = gh_apply (proc, gh_list (this->self_scm_, SCM_UNDEFINED));
 253
 254
 255   SCM origin =get_elt_property ("origin");
 256   if (!unsmob_input (origin))
 257     origin =ly_symbol2scm ("no-origin");
 258
 259   if (gh_pair_p (mol))
 260     {
 261       // ugr.
 262         mol = gh_cons (gh_list (origin, gh_car (mol), SCM_UNDEFINED), gh_cdr (mol));
 263     }
 264
 265
 266   return create_molecule (mol);
 267 }
 268
 269
 270 /*
 271
 272   VIRTUAL STUBS
 273
 274  */
 275 void
 276 Score_element::do_break_processing()
 277 {
 278 }
 279
 280
 281 void
 282 Score_element::do_add_processing()
 283 {
 284 }
 285
 286
 287 MAKE_SCHEME_CALLBACK(Score_element,brew_molecule)
 288
 289 /*
 290   ugh.
 291  */
 292 SCM
 293 Score_element::brew_molecule (SCM smob)
 294 {
 295   Score_element * sc = unsmob_element (smob);
 296   SCM glyph = sc->get_elt_property ("glyph");
 297   if (gh_string_p (glyph))
 298     {
 299       return sc->lookup_l ()->afm_find (String (ly_scm2string (glyph))).create_scheme ();
 300     }
 301   else
 302     {
 303       return SCM_EOL;
 304     }
 305 }
 306
 307
 308 Line_of_score *
 309 Score_element::line_l() const
 310 {
 311   return 0;
 312 }
 313
 314 void
 315 Score_element::add_dependency (Score_element*e)
 316 {
 317   if (e)
 318     {
 319       Pointer_group_interface gi (this, "dependencies");
 320       gi.add_element (e);
 321     }
 322   else
 323     programming_error ("Null dependency added");
 324 }
 325
 326
 327
 328
 329 /**
 330       Do break substitution in S, using CRITERION. Return new value.
 331       CRITERION is either a SMOB pointer to the desired line, or a number
 332       representing the break direction. Do not modify SRC.
 333 */
 334 SCM
 335 Score_element::handle_broken_smobs (SCM src, SCM criterion)
 336 {
 337  again:
 338   Score_element *sc = unsmob_element (src);
 339   if (sc)
 340     {
 341       if (gh_number_p (criterion))
 342         {
 343           Item * i = dynamic_cast<Item*> (sc);
 344           Direction d = to_dir (criterion);
 345           if (i && i->break_status_dir () != d)
 346             {
 347               Item *br = i->find_prebroken_piece (d);
 348               return  (br) ? br->self_scm_ : SCM_UNDEFINED;
 349             }
 350         }
 351       else
 352         {
 353           Line_of_score * line
 354             = dynamic_cast<Line_of_score*> (unsmob_element (criterion));
 355           if (sc->line_l () != line)
 356             {
 357               sc = sc->find_broken_piece (line);
 358
 359             }
 360
 361           /* now: !sc || (sc && sc->line_l () == line) */
 362           if (!sc)
 363             return SCM_UNDEFINED;
 364
 365           /* now: sc && sc->line_l () == line */
 366           if (!line
 367               || (sc->common_refpoint (line, X_AXIS)
 368                   && sc->common_refpoint (line, Y_AXIS)))
 369             {
 370               return sc->self_scm_;
 371             }
 372           return SCM_UNDEFINED;
 373         }
 374     }
 375   else if (gh_pair_p (src))
 376     {
 377       SCM oldcar =gh_car (src);
 378       /*
 379         UGH! breaks on circular lists.
 380       */
 381       SCM newcar = handle_broken_smobs (oldcar, criterion);
 382       SCM oldcdr = gh_cdr (src);
 383
 384       if (newcar == SCM_UNDEFINED
 385           && (gh_pair_p (oldcdr) || oldcdr == SCM_EOL))
 386         {
 387           /*
 388             This is tail-recursion, ie.
 389
 390             return handle_broken_smobs (cdr, criterion);
 391
 392             We don't want to rely on the compiler to do this.  Without
 393             tail-recursion, this easily crashes with a stack overflow.  */
 394           src =  oldcdr;
 395           goto again;
 396         }
 397
 398       SCM newcdr = handle_broken_smobs (oldcdr, criterion);
 399       return gh_cons (newcar, newcdr);
 400     }
 401   else
 402     return src;
 403
 404   return src;
 405 }
 406
 407 void
 408 Score_element::handle_broken_dependencies()
 409 {
 410   Spanner * s= dynamic_cast<Spanner*> (this);
 411   if (original_l_ && s)
 412     return;
 413
 414   if (s)
 415     {
 416       for (int i = 0;  i< s->broken_into_l_arr_ .size (); i++)
 417         {
 418           Score_element * sc = s->broken_into_l_arr_[i];
 419           Line_of_score * l = sc->line_l ();
 420           sc->mutable_property_alist_ =
 421             handle_broken_smobs (mutable_property_alist_,
 422                                  l ? l->self_scm_ : SCM_UNDEFINED);
 423         }
 424     }
 425
 426
 427   Line_of_score *line = line_l();
 428
 429   if (line && common_refpoint (line, X_AXIS) && common_refpoint (line, Y_AXIS))
 430     {
 431       mutable_property_alist_
 432         = handle_broken_smobs (mutable_property_alist_,
 433                                line ? line->self_scm_ : SCM_UNDEFINED);
 434     }
 435   else if (dynamic_cast <Line_of_score*> (this))
 436     {
 437       mutable_property_alist_ = handle_broken_smobs (mutable_property_alist_,
 438                                             SCM_UNDEFINED);
 439     }
 440   else
 441     {
 442       /*
 443         This element is `invalid'; it has been removed from all
 444         dependencies, so let's junk the element itself.
 445
 446         do not do this for Line_of_score, since that would remove
 447         references to the originals of score-elts, which get then GC'd
 448         (a bad thing.)
 449       */
 450       suicide();
 451     }
 452 }
 453
 454 /*
 455  Note that we still want references to this element to be
 456  rearranged, and not silently thrown away, so we keep pointers
 457  like {broken_into_{drul,array}, original}
 458 */
 459 void
 460 Score_element::suicide ()
 461 {
 462   mutable_property_alist_ = SCM_EOL;
 463   immutable_property_alist_ = SCM_EOL;
 464   set_extent_callback (0, Y_AXIS);
 465   set_extent_callback (0, X_AXIS);
 466
 467   for (int a= X_AXIS; a <= Y_AXIS; a++)
 468     {
 469       dim_cache_[a].off_callbacks_.clear ();
 470     }
 471 }
 472
 473 void
 474 Score_element::handle_prebroken_dependencies()
 475 {
 476 }
 477
 478 Score_element*
 479 Score_element::find_broken_piece (Line_of_score*) const
 480 {
 481   return 0;
 482 }
 483
 484 void
 485 Score_element::translate_axis (Real y, Axis a)
 486 {
 487   if (isinf (y) || isnan (y))
 488     programming_error (_(INFINITY_MSG));
 489   else
 490     {
 491       dim_cache_[a].offset_ += y;
 492     }
 493 }
 494
 495 Real
 496 Score_element::relative_coordinate (Score_element const*refp, Axis a) const
 497 {
 498   if (refp == this)
 499     return 0.0;
 500
 501   /*
 502     We catch PARENT_L_ == nil case with this, but we crash if we did
 503     not ask for the absolute coordinate (ie. REFP == nil.)
 504
 505    */
 506   if (refp == dim_cache_[a].parent_l_)
 507     return get_offset (a);
 508   else
 509     return get_offset (a) + dim_cache_[a].parent_l_->relative_coordinate (refp, a);
 510 }
 511
 512 Real
 513 Score_element::get_offset (Axis a) const
 514 {
 515   Score_element *me = (Score_element*) this;
 516   while (dim_cache_[a].off_callbacks_.size ())
 517     {
 518       Offset_callback c = dim_cache_[a].off_callbacks_[0];
 519       me->dim_cache_[a].off_callbacks_.del (0);
 520       Real r =  (*c) (me,a );
 521       if (isinf (r) || isnan (r))
 522         {
 523           r = 0.0;
 524           programming_error (INFINITY_MSG);
 525         }
 526       me->dim_cache_[a].offset_ +=r;
 527     }
 528   return dim_cache_[a].offset_;
 529 }
 530
 531
 532 Interval
 533 Score_element::point_dimension_callback (Score_element* , Axis)
 534 {
 535   return Interval (0,0);
 536 }
 537
 538 bool
 539 Score_element::empty_b (Axis a)const
 540 {
 541   return !dim_cache_[a].extent_callback_l_;
 542 }
 543
 544 Interval
 545 Score_element::extent (Axis a) const
 546 {
 547   Dimension_cache * d = (Dimension_cache *)&dim_cache_[a];
 548   if (!d->extent_callback_l_)
 549     {
 550       d->dim_.set_empty ();
 551     }
 552   else if (!d->valid_b_)
 553     {
 554       d->dim_= (*d->extent_callback_l_ ) ((Score_element*)this, a);
 555       d->valid_b_ = true;
 556     }
 557
 558   Interval ext = d->dim_;
 559
 560   if (empty_b (a))
 561     return ext;
 562
 563   SCM extra = get_elt_property (a == X_AXIS
 564                                 ? "extra-extent-X"
 565                                 : "extra-extent-Y");
 566
 567   /*
 568     signs ?
 569    */
 570   Real s = paper_l ()->get_var ("staffspace");
 571   if (gh_pair_p (extra))
 572     {
 573       ext[BIGGER] +=  s * gh_scm2double (gh_cdr (extra));
 574       ext[SMALLER] +=  s * gh_scm2double (gh_car (extra));
 575     }
 576
 577   extra = get_elt_property (a == X_AXIS
 578                                 ? "minimum-extent-X"
 579                                 : "minimum-extent-Y");
 580   if (gh_pair_p (extra))
 581     {
 582       ext.unite (Interval (s * gh_scm2double (gh_car (extra)),
 583                            s * gh_scm2double (gh_cdr (extra))));
 584     }
 585
 586   return ext;
 587 }
 588
 589
 590 Score_element*
 591 Score_element::parent_l (Axis a) const
 592 {
 593   return  dim_cache_[a].parent_l_;
 594 }
 595
 596 Score_element *
 597 Score_element::common_refpoint (Score_element const* s, Axis a) const
 598 {
 599   /*
 600     I don't like the quadratic aspect of this code, but I see no other
 601     way. The largest chain of parents might be 10 high or so, so
 602     it shouldn't be a real issue. */
 603   for (Score_element const *c = this; c; c = c->dim_cache_[a].parent_l_)
 604     for (Score_element const * d = s; d; d = d->dim_cache_[a].parent_l_)
 605       if (d == c)
 606         return (Score_element*)d;
 607
 608   return 0;
 609 }
 610
 611
 612 Score_element *
 613 Score_element::common_refpoint (SCM elist, Axis a) const
 614 {
 615   Score_element * common = (Score_element*) this;
 616   for (; gh_pair_p (elist); elist = gh_cdr (elist))
 617     {
 618       Score_element * s = unsmob_element (gh_car (elist));
 619       if (s)
 620         common = common->common_refpoint (s, a);
 621     }
 622
 623   return common;
 624 }
 625
 626 char const *
 627 Score_element::name () const
 628 {
 629   return classname (this);
 630 }
 631
 632 void
 633 Score_element::add_offset_callback (Offset_callback cb, Axis a)
 634 {
 635   dim_cache_[a].off_callbacks_.push (cb);
 636 }
 637
 638 bool
 639 Score_element::has_extent_callback_b (Extent_callback cb, Axis a)const
 640 {
 641   return cb == dim_cache_[a].extent_callback_l_;
 642 }
 643
 644 bool
 645 Score_element::has_offset_callback_b (Offset_callback cb, Axis a)const
 646 {
 647   for (int i= dim_cache_[a].off_callbacks_.size (); i--;)
 648     {
 649       if (dim_cache_[a].off_callbacks_[i] == cb)
 650         return true;
 651     }
 652   return false;
 653 }
 654
 655 void
 656 Score_element::set_extent_callback (Dim_cache_callback dc, Axis a)
 657 {
 658   dim_cache_[a].extent_callback_l_ = dc ;
 659 }
 660
 661
 662 void
 663 Score_element::set_parent (Score_element *g, Axis a)
 664 {
 665   dim_cache_[a].parent_l_ = g;
 666 }
 667
 668 MAKE_SCHEME_CALLBACK(Score_element,fixup_refpoint);
 669 SCM
 670 Score_element::fixup_refpoint (SCM smob)
 671 {
 672   Score_element *me = unsmob_element (smob);
 673   for (int a = X_AXIS; a < NO_AXES; a ++)
 674     {
 675       Axis ax = (Axis)a;
 676       Score_element * parent = me->parent_l (ax);
 677
 678       if (!parent)
 679         continue;
 680
 681       if (parent->line_l () != me->line_l () && me->line_l ())
 682         {
 683           Score_element * newparent = parent->find_broken_piece (me->line_l ());
 684           me->set_parent (newparent, ax);
 685         }
 686
 687       if (Item * i  = dynamic_cast<Item*> (me))
 688         {
 689           Item *parenti = dynamic_cast<Item*> (parent);
 690
 691           if (parenti && i)
 692             {
 693               Direction  my_dir = i->break_status_dir () ;
 694               if (my_dir!= parenti->break_status_dir())
 695                 {
 696                   Item *newparent =  parenti->find_prebroken_piece (my_dir);
 697                   me->set_parent (newparent, ax);
 698                 }
 699             }
 700         }
 701     }
 702   return smob;
 703 }
 704
 705
 706
 707 /****************************************************
 708   SMOB funcs
 709  ****************************************************/
 710
 711 #include "ly-smobs.icc"
 712
 713 IMPLEMENT_UNSMOB(Score_element, element);
 714 IMPLEMENT_SMOBS(Score_element);
 715
 716 SCM
 717 Score_element::mark_smob (SCM ses)
 718 {
 719   Score_element * s = SMOB_TO_TYPE (Score_element, ses);
 720   if (s->self_scm_ != ses)
 721     {
 722       programming_error ("SMOB marking gone awry");
 723       return SCM_EOL;
 724     }
 725   scm_gc_mark (s->immutable_property_alist_);
 726   scm_gc_mark (s->mutable_property_alist_);
 727
 728   if (s->parent_l (Y_AXIS))
 729     scm_gc_mark (s->parent_l (Y_AXIS)->self_scm_);
 730   if (s->parent_l (X_AXIS))
 731     scm_gc_mark (s->parent_l (X_AXIS)->self_scm_);
 732
 733   if (s->original_l_)
 734     scm_gc_mark (s->original_l_->self_scm_);
 735   return s->do_derived_mark ();
 736 }
 737
 738 int
 739 Score_element::print_smob (SCM s, SCM port, scm_print_state *)
 740 {
 741   Score_element *sc = (Score_element *) gh_cdr (s);
 742
 743   scm_puts ("#<Score_element ", port);
 744   scm_puts ((char *)sc->name (), port);
 745
 746   /*
 747     don't try to print properties, that is too much hassle.
 748    */
 749   scm_puts (" >", port);
 750   return 1;
 751 }
 752
 753 SCM
 754 Score_element::do_derived_mark ()
 755 {
 756   return SCM_EOL;
 757 }
 758
 759 void
 760 Score_element::do_smobify_self ()
 761 {
 762 }
 763
 764 SCM
 765 Score_element::equal_p (SCM a, SCM b)
 766 {
 767   return gh_cdr(a) == gh_cdr(b) ? SCM_BOOL_T : SCM_BOOL_F;
 768 }
 769
 770
 771 SCM
 772 ly_set_elt_property (SCM elt, SCM sym, SCM val)
 773 {
 774   Score_element * sc = unsmob_element (elt);
 775
 776   if (!gh_symbol_p (sym))
 777     {
 778       error ("Not a symbol");
 779       ly_display_scm (sym);
 780       return SCM_UNSPECIFIED;
 781     }
 782
 783   if (sc)
 784     {
 785       sc->set_elt_property (sym, val);
 786     }
 787   else
 788     {
 789       error ("Not a score element");
 790       ly_display_scm (elt);
 791     }
 792
 793   return SCM_UNSPECIFIED;
 794 }
 795
 796
 797 SCM
 798 ly_get_elt_property (SCM elt, SCM sym)
 799 {
 800   Score_element * sc = unsmob_element (elt);
 801
 802   if (sc)
 803     {
 804       return sc->get_elt_property (sym);
 805     }
 806   else
 807     {
 808       error ("Not a score element");
 809       ly_display_scm (elt);
 810     }
 811   return SCM_UNSPECIFIED;
 812 }
 813
 814
 815 void
 816 Score_element::discretionary_processing()
 817 {
 818 }
 819
 820
 821
 822 SCM
 823 spanner_get_bound (SCM slur, SCM dir)
 824 {
 825   return dynamic_cast<Spanner*> (unsmob_element (slur))->get_bound (to_dir (dir))->self_scm_;
 826 }
 827
 828
 829
 830 static SCM interfaces_sym;
 831
 832 static void
 833 init_functions ()
 834 {
 835   interfaces_sym = scm_permanent_object (ly_symbol2scm ("interfaces"));
 836
 837   scm_make_gsubr ("ly-get-elt-property", 2, 0, 0, (SCM(*)(...))ly_get_elt_property);
 838   scm_make_gsubr ("ly-set-elt-property", 3, 0, 0, (SCM(*)(...))ly_set_elt_property);
 839   scm_make_gsubr ("ly-get-spanner-bound", 2 , 0, 0, (SCM(*)(...)) spanner_get_bound);
 840 }
 841
 842 bool
 843 Score_element::has_interface (SCM k)
 844 {
 845   if (mutable_property_alist_ == SCM_EOL)
 846     return false;
 847
 848   SCM ifs = get_elt_property (interfaces_sym);
 849
 850   return scm_memq (k, ifs) != SCM_BOOL_F;
 851 }
 852
 853 void
 854 Score_element::set_interface (SCM k)
 855 {
 856   if (has_interface (k))
 857     return ;
 858   else
 859     {
 860       set_elt_property (interfaces_sym,
 861                         gh_cons  (k, get_elt_property (interfaces_sym)));
 862     }
 863 }
 864
 865
 866 ADD_SCM_INIT_FUNC(scoreelt, init_functions);
 867