interpretor/faust-0.9.47mr3/compiler/evaluate/eval.cpp

   1 /************************************************************************
   2  ************************************************************************
   3     FAUST compiler
   4         Copyright (C) 2003-2004 GRAME, Centre National de Creation Musicale
   5     ---------------------------------------------------------------------
   6     This program 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 2 of the License, or
   9     (at your option) any later version.
  10
  11     This program 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 this program; if not, write to the Free Software
  18     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  ************************************************************************
  20  ************************************************************************/
  21  #define TRACE
  22
  23 /**
  24  * \file eval.cpp
  25  * Implementation of the Block diagram evaluator.
  26  *
  27  * A strict lambda-calculus evaluator for block diagram expressions.
  28  *
  29  **/
  30
  31
  32 #include "eval.hh"
  33 #include <stdio.h>
  34 #include "errormsg.hh"
  35 #include "ppbox.hh"
  36 #include "simplify.hh"
  37 #include "propagate.hh"
  38 #include "patternmatcher.hh"
  39 #include "signals.hh"
  40 #include "xtended.hh"
  41 #include "loopDetector.hh"
  42 #include "property.hh"
  43 #include "names.hh"
  44 #include "compatibility.hh"
  45
  46
  47 #include <assert.h>
  48 extern SourceReader     gReader;
  49 extern int  gMaxNameSize;
  50 extern bool     gSimpleNames;
  51 extern bool gSimplifyDiagrams;
  52 // History
  53 // 23/05/2005 : New environment management
  54
  55
  56 //-------------- prototypes ---------------------------------------------------------
  57 static Tree     a2sb(Tree exp);
  58 static Tree     eval (Tree exp, Tree visited, Tree localValEnv);
  59 static Tree     realeval (Tree exp, Tree visited, Tree localValEnv);
  60 static Tree     revEvalList (Tree lexp, Tree visited, Tree localValEnv);
  61 static Tree     applyList (Tree fun, Tree larg);
  62 static Tree     iteratePar (Tree var, int num, Tree body, Tree visited, Tree localValEnv);
  63 static Tree     iterateSeq (Tree id, int num, Tree body, Tree visited, Tree localValEnv);
  64 static Tree     iterateSum (Tree id, int num, Tree body, Tree visited, Tree localValEnv);
  65 static Tree     iterateProd (Tree id, int num, Tree body, Tree visited, Tree localValEnv);
  66 static Tree     larg2par (Tree larg);
  67 static int              eval2int (Tree exp, Tree visited, Tree localValEnv);
  68 static double   eval2double (Tree exp, Tree visited, Tree localValEnv);
  69 static const char * evalLabel (const char* l, Tree visited, Tree localValEnv);
  70
  71 static Tree             evalIdDef(Tree id, Tree visited, Tree env);
  72
  73
  74
  75 static Tree             evalCase(Tree rules, Tree env);
  76 static Tree             evalRuleList(Tree rules, Tree env);
  77 static Tree             evalRule(Tree rule, Tree env);
  78 static Tree             evalPatternList(Tree patterns, Tree env);
  79 static Tree             evalPattern(Tree pattern, Tree env);
  80
  81 static Tree     patternSimplification (Tree pattern);
  82 static bool     isBoxNumeric (Tree in, Tree& out);
  83
  84 static Tree     vec2list(const vector<Tree>& v);
  85 static void     list2vec(Tree l, vector<Tree>& v);
  86 static Tree     listn (int n, Tree e);
  87
  88 static Tree     boxSimplification(Tree box);
  89
  90 // Public Interface
  91 //----------------------
  92
  93
  94 /**
  95  * Eval "process" from a list of definitions.
  96  *
  97  * Strict evaluation of a block diagram expression by applying beta reduction.
  98  * @param eqlist a list of faust defintions forming the the global environment
  99  * @return the process block diagram in normal form
 100  */
 101 Tree evalprocess (Tree eqlist)
 102 {
 103     Tree b = a2sb(eval(boxIdent("process"), nil, pushMultiClosureDefs(eqlist, nil, nil)));
 104
 105     if (gSimplifyDiagrams) {
 106         b = boxSimplification(b);
 107     }
 108
 109     return b;
 110 }
 111
 112
 113 /* Eval a documentation expression. */
 114
 115 Tree evaldocexpr (Tree docexpr, Tree eqlist)
 116 {
 117         return a2sb(eval(docexpr, nil, pushMultiClosureDefs(eqlist, nil, nil)));
 118 }
 119
 120
 121
 122 // Private Implementation
 123 //------------------------
 124
 125 /**
 126  * Transform unused (unapplied) closures into symbolic boxes
 127  *
 128  * @param exp the expression to transform
 129  * @return an expression where abstractions have been replaced by symbolic boxes
 130  */
 131
 132 property<Tree> gSymbolicBoxProperty;
 133
 134 static Tree real_a2sb(Tree exp);
 135
 136 static Tree a2sb(Tree exp)
 137 {
 138     Tree    result;
 139     Tree    id;
 140
 141     if (gSymbolicBoxProperty.get(exp, result)) {
 142         return result;
 143     }
 144
 145         result = real_a2sb(exp);
 146         if (result != exp && getDefNameProperty(exp, id)) {
 147                 setDefNameProperty(result, id);         // propagate definition name property when needed
 148         }
 149     gSymbolicBoxProperty.set(exp, result);
 150         return result;
 151 }
 152
 153 static int      gBoxSlotNumber = 0;             ///< counter for unique slot number
 154
 155 static Tree real_a2sb(Tree exp)
 156 {
 157         Tree abstr, visited, unusedEnv, localValEnv, var, name, body;
 158
 159         if (isClosure(exp, abstr, unusedEnv, visited, localValEnv)) {
 160
 161                 if (isBoxIdent(abstr)) {
 162                         // special case introduced with access and components
 163                         Tree result = a2sb(eval(abstr, visited, localValEnv));
 164
 165                         // propagate definition name property when needed
 166                         if (getDefNameProperty(exp, name))      setDefNameProperty(result, name);
 167                         return result;
 168
 169                 } else if (isBoxAbstr(abstr, var, body)) {
 170                         // Here we have remaining abstraction that we will try to
 171                         // transform in a symbolic box by applying it to a slot
 172
 173                         Tree slot = boxSlot(++gBoxSlotNumber);
 174                         stringstream s; s << boxpp(var);
 175                         setDefNameProperty(slot, s.str() ); // ajout YO
 176
 177                         // Apply the abstraction to the slot
 178                         Tree result = boxSymbolic(slot, a2sb(eval(body, visited, pushValueDef(var, slot, localValEnv))));
 179
 180                         // propagate definition name property when needed
 181                         if (getDefNameProperty(exp, name)) setDefNameProperty(result, name);
 182                         return result;
 183
 184         } else if (isBoxEnvironment(abstr)) {
 185             return abstr;
 186
 187                 } else {
 188                         evalerror(yyfilename, -1, " a2sb : internal error : not an abstraction inside closure ", exp);
 189                         exit(1);
 190                 }
 191
 192         } else if (isBoxPatternMatcher(exp)) {
 193                 // Here we have remaining PM rules that we will try to
 194                 // transform in a symbolic box by applying it to a slot
 195
 196                 Tree slot = boxSlot(++gBoxSlotNumber);
 197                 stringstream s; s << "PM" << gBoxSlotNumber;
 198                 setDefNameProperty(slot, s.str() );
 199
 200                 // apply the PM rules to the slot and transfoms the result in a symbolic box
 201                 Tree result = boxSymbolic(slot, a2sb(applyList(exp, cons(slot,nil))));
 202
 203                 // propagate definition name property when needed
 204                 if (getDefNameProperty(exp, name)) setDefNameProperty(result, name);
 205                 return result;
 206
 207         } else {
 208                 // it is a constructor : transform each branches
 209         unsigned int    ar = exp->arity();
 210                 tvec            B(ar);
 211         bool            modified = false;
 212                 for (unsigned int i = 0; i < ar; i++) {
 213             Tree b = exp->branch(i);
 214             Tree m = a2sb(b);
 215             B[i] = m;
 216             if (b != m) modified=true;
 217                 }
 218         Tree r = (modified) ? CTree::make(exp->node(), B) : exp;
 219         return r;
 220         }
 221 }
 222
 223 static bool autoName(Tree exp , Tree& id)
 224 {
 225         stringstream s; s << boxpp(exp);
 226         id = tree(s.str().c_str());
 227         return true;
 228 }
 229
 230 bool getArgName(Tree t, Tree& id)
 231 {
 232         //return getDefNameProperty(t, id) || autoName(t, id) ;
 233         return autoName(t, id) ;
 234 }
 235
 236
 237
 238 /**
 239  * Eval a block diagram expression.
 240  *
 241  * Wrap the realeval function in order to propagate the name property
 242  * @param exp the expression to evaluate
 243  * @param visited list of visited definition to detect recursive definitions
 244  * @param localValEnv the local environment
 245  * @return a block diagram in normal form
 246  */
 247 static loopDetector LD(1024, 512);
 248
 249
 250 static Node EVALPROPERTY(symbol("EvalProperty"));
 251
 252 /**
 253  * set the value of box in the environment env
 254  * @param box the block diagram we have evaluated
 255  * @param env the evaluation environment
 256  * @param value the evaluated block diagram
 257  */
 258 void setEvalProperty(Tree box, Tree env, Tree value)
 259 {
 260     setProperty(box, tree(EVALPROPERTY,env), value);
 261 }
 262
 263
 264 /**
 265  * retrieve the value of box in the environment env
 266  * @param box the expression we want to retrieve the value
 267  * @param env the lexical environment
 268  * @param value the returned value if any
 269  * @return true if a value already exist
 270  */
 271 bool getEvalProperty(Tree box, Tree env, Tree& value)
 272 {
 273         return getProperty(box, tree(EVALPROPERTY,env), value);
 274 }
 275
 276
 277 static Tree eval (Tree exp, Tree visited, Tree localValEnv)
 278 {
 279         Tree    id;
 280         Tree    result;
 281
 282     if (!getEvalProperty(exp, localValEnv, result)) {
 283         LD.detect(cons(exp,localValEnv));
 284         //cerr << "ENTER eval("<< *exp << ") with env " << *localValEnv << endl;
 285                 result = realeval(exp, visited, localValEnv);
 286                 setEvalProperty(exp, localValEnv, result);
 287         //cerr << "EXIT eval(" << *exp << ") IS " << *result << " with env " << *localValEnv << endl;
 288                 if (getDefNameProperty(exp, id)) {
 289                         setDefNameProperty(result, id);         // propagate definition name property
 290                 }
 291         }
 292         return result;
 293 }
 294
 295 /**
 296  * Eval a block diagram expression.
 297  *
 298  * Strict evaluation of a block diagram expression by applying beta reduction.
 299  * @param exp the expression to evaluate
 300  * @param visited list of visited definition to detect recursive definitions
 301  * @param localValEnv the local environment
 302  * @return a block diagram in normal form
 303  */
 304
 305 static Tree realeval (Tree exp, Tree visited, Tree localValEnv)
 306 {
 307         //Tree  def;
 308         Tree    fun;
 309         Tree    arg;
 310         Tree    var, num, body, ldef;
 311         Tree    label;
 312         Tree    cur, lo, hi, step;
 313         Tree    e1, e2, exp2, notused, visited2, lenv2;
 314         Tree    rules;
 315         Tree    id;
 316
 317         //cerr << "EVAL " << *exp << " (visited : " << *visited << ")" << endl;
 318     //cerr << "REALEVAL of " << *exp << endl;
 319
 320         xtended* xt = (xtended*) getUserData(exp);
 321
 322
 323         // constants
 324         //-----------
 325
 326         if (    xt ||
 327                         isBoxInt(exp) || isBoxReal(exp) ||
 328                         isBoxWire(exp) || isBoxCut(exp) ||
 329                         isBoxPrim0(exp) || isBoxPrim1(exp) ||
 330                         isBoxPrim2(exp) || isBoxPrim3(exp) ||
 331                         isBoxPrim4(exp) || isBoxPrim5(exp) ||
 332                         isBoxFFun(exp) || isBoxFConst(exp) || isBoxFVar(exp) ) {
 333                 return exp;
 334
 335         // block-diagram constructors
 336         //---------------------------
 337
 338         } else if (     isBoxSeq(exp, e1, e2) ) {
 339                 return boxSeq(eval(e1, visited, localValEnv), eval(e2, visited, localValEnv));
 340
 341         } else if (     isBoxPar(exp, e1, e2) ) {
 342                 return boxPar(eval(e1, visited, localValEnv), eval(e2, visited, localValEnv));
 343
 344         } else if (     isBoxRec(exp, e1, e2) ) {
 345                 return boxRec(eval(e1, visited, localValEnv), eval(e2, visited, localValEnv));
 346
 347         } else if (     isBoxSplit(exp, e1, e2) ) {
 348                 return boxSplit(eval(e1, visited, localValEnv), eval(e2, visited, localValEnv));
 349
 350         } else if (     isBoxMerge(exp, e1, e2) ) {
 351                 return boxMerge(eval(e1, visited, localValEnv), eval(e2, visited, localValEnv));
 352
 353         // Modules
 354         //--------
 355
 356     } else if (isBoxAccess(exp, body, var)) {
 357         Tree val = eval(body, visited, localValEnv);
 358         if (isClosure(val, exp2, notused, visited2, lenv2)) {
 359             // it is a closure, we have an environment to access
 360             return eval(closure(var,notused,visited2,lenv2), visited, localValEnv);
 361         } else {
 362             evalerror(getDefFileProp(exp), getDefLineProp(exp), "No environment to access ", exp);
 363             exit(1);
 364         }
 365
 366 //////////////////////en chantier////////////////////////////
 367
 368     } else if (isBoxModifLocalDef(exp, body, ldef)) {
 369         Tree val = eval(body, visited, localValEnv);
 370         if (isClosure(val, exp2, notused, visited2, lenv2)) {
 371             // we rebuild the closure using a copy of the original environment
 372             // modified with some new definitions
 373             Tree lenv3 = copyEnvReplaceDefs(lenv2, ldef, visited2, localValEnv);
 374             return eval(closure(exp2,notused,visited2,lenv3), visited, localValEnv);
 375         } else {
 376
 377             evalerror(getDefFileProp(exp), getDefLineProp(exp), "not a closure ", val);
 378             evalerror(getDefFileProp(exp), getDefLineProp(exp), "No environment to access ", exp);
 379             exit(1);
 380         }
 381
 382 ///////////////////////////////////////////////////////////////////
 383
 384     } else if (isBoxComponent(exp, label)) {
 385         string  fname   = tree2str(label);
 386         Tree    eqlst   = gReader.expandlist(gReader.getlist(fname));
 387         Tree    res     = closure(boxIdent("process"), nil, nil, pushMultiClosureDefs(eqlst, nil, nil));
 388         setDefNameProperty(res, label);
 389         //cerr << "component is " << boxpp(res) << endl;
 390         return res;
 391
 392     } else if (isBoxLibrary(exp, label)) {
 393         string  fname   = tree2str(label);
 394         Tree    eqlst   = gReader.expandlist(gReader.getlist(fname));
 395         Tree    res     = closure(boxEnvironment(), nil, nil, pushMultiClosureDefs(eqlst, nil, nil));
 396         setDefNameProperty(res, label);
 397         //cerr << "component is " << boxpp(res) << endl;
 398         return res;
 399
 400
 401         // user interface elements
 402         //------------------------
 403
 404         } else if (isBoxButton(exp, label)) {
 405                 const char* l1 = tree2str(label);
 406                 const char* l2= evalLabel(l1, visited, localValEnv);
 407                 //cout << "button label : " << l1 << " become " << l2 << endl;
 408                 return ((l1 == l2) ? exp : boxButton(tree(l2)));
 409
 410         } else if (isBoxCheckbox(exp, label)) {
 411                 const char* l1 = tree2str(label);
 412                 const char* l2= evalLabel(l1, visited, localValEnv);
 413                 //cout << "check box label : " << l1 << " become " << l2 << endl;
 414                 return ((l1 == l2) ? exp : boxCheckbox(tree(l2)));
 415
 416         } else if (isBoxVSlider(exp, label, cur, lo, hi, step)) {
 417                 const char* l1 = tree2str(label);
 418                 const char* l2= evalLabel(l1, visited, localValEnv);
 419                 return ( boxVSlider(tree(l2),
 420                                         tree(eval2double(cur, visited, localValEnv)),
 421                                         tree(eval2double(lo, visited, localValEnv)),
 422                                         tree(eval2double(hi, visited, localValEnv)),
 423                                         tree(eval2double(step, visited, localValEnv))));
 424
 425         } else if (isBoxHSlider(exp, label, cur, lo, hi, step)) {
 426                 const char* l1 = tree2str(label);
 427                 const char* l2= evalLabel(l1, visited, localValEnv);
 428                 return ( boxHSlider(tree(l2),
 429                                         tree(eval2double(cur, visited, localValEnv)),
 430                                         tree(eval2double(lo, visited, localValEnv)),
 431                                         tree(eval2double(hi, visited, localValEnv)),
 432                                         tree(eval2double(step, visited, localValEnv))));
 433
 434         } else if (isBoxNumEntry(exp, label, cur, lo, hi, step)) {
 435                 const char* l1 = tree2str(label);
 436                 const char* l2= evalLabel(l1, visited, localValEnv);
 437                 return (boxNumEntry(tree(l2),
 438                                         tree(eval2double(cur, visited, localValEnv)),
 439                                         tree(eval2double(lo, visited, localValEnv)),
 440                                         tree(eval2double(hi, visited, localValEnv)),
 441                                         tree(eval2double(step, visited, localValEnv))));
 442
 443         } else if (isBoxVGroup(exp, label, arg)) {
 444                 const char* l1 = tree2str(label);
 445                 const char* l2= evalLabel(l1, visited, localValEnv);
 446                 return boxVGroup(tree(l2),      eval(arg, visited, localValEnv) );
 447
 448         } else if (isBoxHGroup(exp, label, arg)) {
 449                 const char* l1 = tree2str(label);
 450                 const char* l2= evalLabel(l1, visited, localValEnv);
 451                 return boxHGroup(tree(l2),      eval(arg, visited, localValEnv) );
 452
 453         } else if (isBoxTGroup(exp, label, arg)) {
 454                 const char* l1 = tree2str(label);
 455                 const char* l2= evalLabel(l1, visited, localValEnv);
 456                 return boxTGroup(tree(l2),      eval(arg, visited, localValEnv) );
 457
 458         } else if (isBoxHBargraph(exp, label, lo, hi)) {
 459                 const char* l1 = tree2str(label);
 460                 const char* l2= evalLabel(l1, visited, localValEnv);
 461                 return boxHBargraph(tree(l2),
 462                                         tree(eval2double(lo, visited, localValEnv)),
 463                                         tree(eval2double(hi, visited, localValEnv)));
 464
 465         } else if (isBoxVBargraph(exp, label, lo, hi)) {
 466                 const char* l1 = tree2str(label);
 467                 const char* l2= evalLabel(l1, visited, localValEnv);
 468                 return boxVBargraph(tree(l2),
 469                                         tree(eval2double(lo, visited, localValEnv)),
 470                                         tree(eval2double(hi, visited, localValEnv)));
 471
 472         // lambda calculus
 473         //----------------
 474
 475         } else if (isBoxIdent(exp)) {
 476                 return evalIdDef(exp, visited, localValEnv);
 477
 478         } else if (isBoxWithLocalDef(exp, body, ldef)) {
 479                 return eval(body, visited, pushMultiClosureDefs(ldef, visited, localValEnv));
 480
 481         } else if (isBoxAppl(exp, fun, arg)) {
 482         return applyList( eval(fun, visited, localValEnv),
 483                                                   revEvalList(arg, visited, localValEnv) );
 484
 485     } else if (isBoxAbstr(exp)) {
 486         // it is an abstraction : return a closure
 487         return closure(exp, nil, visited, localValEnv);
 488
 489     } else if (isBoxEnvironment(exp)) {
 490         // environment : return also a closure
 491         return closure(exp, nil, visited, localValEnv);
 492
 493         } else if (isClosure(exp, exp2, notused, visited2, lenv2)) {
 494
 495         if (isBoxAbstr(exp2)) {
 496             // a 'real' closure
 497             return closure(exp2, nil, setUnion(visited,visited2), lenv2);
 498         } else if (isBoxEnvironment(exp2)) {
 499             // a 'real' closure
 500             return closure(exp2, nil, setUnion(visited,visited2), lenv2);
 501         } else {
 502                         // it was a suspended evaluation
 503                         return eval(exp2, setUnion(visited,visited2), lenv2);
 504                 }
 505
 506         // Algorithmic constructions
 507         //--------------------------
 508
 509         } else if (isBoxIPar(exp, var, num, body)) {
 510                 int n = eval2int(num, visited, localValEnv);
 511                 return iteratePar(var, n, body, visited, localValEnv);
 512
 513         } else if (isBoxISeq(exp, var, num, body)) {
 514                 int n = eval2int(num, visited, localValEnv);
 515                 return iterateSeq(var, n, body, visited, localValEnv);
 516
 517         } else if (isBoxISum(exp, var, num, body)) {
 518                 int n = eval2int(num, visited, localValEnv);
 519                 return iterateSum(var, n, body, visited, localValEnv);
 520
 521         } else if (isBoxIProd(exp, var, num, body)) {
 522                 int n = eval2int(num, visited, localValEnv);
 523                 return iterateProd(var, n, body, visited, localValEnv);
 524
 525         } else if (isBoxSlot(exp))              {
 526                 return exp;
 527
 528         } else if (isBoxSymbolic(exp))  {
 529
 530                 return exp;
 531
 532
 533         // Pattern matching extension
 534         //---------------------------
 535
 536         } else if (isBoxCase(exp, rules)) {
 537         return evalCase(rules, localValEnv);
 538
 539         } else if (isBoxPatternVar(exp, id)) {
 540                 return exp;
 541                 //return evalIdDef(id, visited, localValEnv);
 542
 543         } else if (isBoxPatternMatcher(exp)) {
 544                 return exp;
 545
 546         } else {
 547                 cerr << "ERROR : EVAL don't intercept : " << *exp << endl;
 548                 assert(false);
 549         }
 550 }
 551
 552 /* Deconstruct a (BDA) op pattern (YO). */
 553
 554 static inline bool isBoxPatternOp(Tree box, Node& n, Tree& t1, Tree& t2)
 555 {
 556     if (    isBoxPar(box, t1, t2) ||
 557             isBoxSeq(box, t1, t2) ||
 558             isBoxSplit(box, t1, t2) ||
 559             isBoxMerge(box, t1, t2) ||
 560             isBoxRec(box, t1, t2)    )
 561     {
 562         n = box->node();
 563         return true;
 564     } else {
 565         return false;
 566     }
 567 }
 568
 569
 570 Tree NUMERICPROPERTY = tree(symbol("NUMERICPROPERTY"));
 571
 572 void setNumericProperty(Tree t, Tree num)
 573 {
 574         setProperty(t, NUMERICPROPERTY, num);
 575 }
 576
 577 bool getNumericProperty(Tree t, Tree& num)
 578 {
 579         return getProperty(t, NUMERICPROPERTY, num);
 580 }
 581
 582 /**
 583  * Simplify a block-diagram pattern by computing its numerical sub-expressions
 584  * \param pattern an evaluated block-diagram
 585  * \return a simplified pattern
 586  *
 587  */
 588 /* uncomment for debugging output */
 589 //#define DEBUG
 590 Tree simplifyPattern (Tree value)
 591 {
 592         Tree num;
 593         if (!getNumericProperty(value,num)) {
 594                 if (!isBoxNumeric(value,num)) {
 595                         num = value;
 596                 }
 597                 setNumericProperty(value,num);
 598         }
 599         return num;
 600 }
 601
 602
 603 static bool isBoxNumeric (Tree in, Tree& out)
 604 {
 605     int         numInputs, numOutputs;
 606     double      x;
 607     int         i;
 608     Tree        v;
 609
 610     if (isBoxInt(in, &i) || isBoxReal(in, &x)) {
 611         out = in;
 612         return true;
 613     } else {
 614         v = a2sb(in);
 615         if ( getBoxType(v, &numInputs, &numOutputs) && (numInputs == 0) && (numOutputs == 1) ) {
 616             // potential numerical expression
 617             Tree lsignals = boxPropagateSig(nil, v , makeSigInputList(numInputs) );
 618             Tree res = simplify(hd(lsignals));
 619             if (isSigReal(res, &x))     {
 620             out = boxReal(x);
 621             return true;
 622             }
 623             if (isSigInt(res, &i))      {
 624             out = boxInt(i);
 625             return true;
 626             }
 627         }
 628         return false;
 629     }
 630 }
 631
 632 static Tree patternSimplification (Tree pattern)
 633 {
 634
 635         Node    n(0);
 636         Tree    v, t1, t2;
 637
 638         if (isBoxNumeric(pattern, v)) {
 639                 return v;
 640         } else if (isBoxPatternOp(pattern, n, t1, t2)) {
 641                 return tree(n, patternSimplification(t1), patternSimplification(t2));
 642         } else {
 643                 return pattern;
 644         }
 645 }
 646
 647
 648
 649 /**
 650  * Eval a block diagram to a double.
 651  *
 652  * Eval a block diagram that represent a double constant. This function first eval
 653  * a block diagram to its normal form, then check it represent a numerical value (a
 654  * block diagram of type : 0->1) then do a symbolic propagation and try to convert the
 655  * resulting signal to a double.
 656  * @param exp the expression to evaluate
 657  * @param globalDefEnv the global environment
 658  * @param visited list of visited definition to detect recursive definitions
 659  * @param localValEnv the local environment
 660  * @return a block diagram in normal form
 661  */
 662 static double eval2double (Tree exp, Tree visited, Tree localValEnv)
 663 {
 664     Tree diagram = a2sb(eval(exp, visited, localValEnv)); // pour getBoxType
 665         int numInputs, numOutputs;
 666         getBoxType(diagram, &numInputs, &numOutputs);
 667         if ( (numInputs > 0) || (numOutputs != 1) ) {
 668                 evalerror (yyfilename, yylineno, "not a constant expression of type : (0->1)", exp);
 669                 return 1;
 670         } else {
 671                 Tree lsignals = boxPropagateSig(nil, diagram , makeSigInputList(numInputs) );
 672                 Tree val = simplify(hd(lsignals));
 673                 return tree2float(val);
 674         }
 675 }
 676
 677
 678 /**
 679  * Eval a block diagram to an int.
 680  *
 681  * Eval a block diagram that represent an integer constant. This function first eval
 682  * a block diagram to its normal form, then check it represent a numerical value (a
 683  * block diagram of type : 0->1) then do a symbolic propagation and try to convert the
 684  * resulting signal to an int.
 685  * @param exp the expression to evaluate
 686  * @param globalDefEnv the global environment
 687  * @param visited list of visited definition to detect recursive definitions
 688  * @param localValEnv the local environment
 689  * @return a block diagram in normal form
 690  */
 691 static int eval2int (Tree exp, Tree visited, Tree localValEnv)
 692 {
 693     Tree diagram = a2sb(eval(exp, visited, localValEnv));   // pour getBoxType()
 694         int numInputs, numOutputs;
 695         getBoxType(diagram, &numInputs, &numOutputs);
 696         if ( (numInputs > 0) || (numOutputs != 1) ) {
 697                 evalerror (yyfilename, yylineno, "not a constant expression of type : (0->1)", exp);
 698                 return 1;
 699         } else {
 700                 Tree lsignals = boxPropagateSig(nil, diagram , makeSigInputList(numInputs) );
 701                 Tree val = simplify(hd(lsignals));
 702                 return tree2int(val);
 703         }
 704 }
 705
 706 static bool isDigitChar(char c)
 707 {
 708     return (c >= '0') & (c <= '9');
 709 }
 710
 711 static bool isIdentChar(char c)
 712 {
 713     return ((c >= 'a') & (c <= 'z')) || ((c >= 'A') & (c <= 'Z')) || ((c >= '0') & (c <= '9')) || (c == '_');
 714 }
 715
 716 const char* Formats [] = {"%d", "%1d", "%2d", "%3d", "%4d"};
 717
 718 static char* writeIdentValue(char* dst, int format, const char* ident, Tree visited, Tree localValEnv)
 719 {
 720         int n = eval2int(boxIdent(ident), visited, localValEnv);
 721     int i = min(4,max(format,0));
 722
 723         return dst + sprintf(dst, Formats[i], n);
 724 }
 725
 726 static const char * evalLabel (const char* label, Tree visited, Tree localValEnv)
 727 {
 728         char            res[2000];
 729         char            ident[64];
 730
 731         const char* src = &label[0];
 732         char*           dst = &res[0];
 733         char*           id  = &ident[0];
 734
 735         bool            parametric = false;
 736         int             state = 0; int format = 0;
 737         char            c;
 738
 739         while ((c=*src++)) {
 740                 if (state == 0) {
 741                         // outside ident mode
 742                         if (c == '%') {
 743                                 // look ahead for next char
 744                                 if (*src == '%') {
 745                                         *dst++ = *src++;                // copy escape char and skip one char
 746                                 } else {
 747                                         state = 1;                              // prepare ident mode
 748                     format = 0;
 749                                         parametric = true;
 750                                         id  = &ident[0];
 751                                 }
 752                         } else {
 753                                 *dst++ = c;                                     // copy char
 754                         }
 755                 } else if (state == 1) {
 756             // read the format
 757             if (isDigitChar(c)) {
 758                 format = format*10 + (c-'0');
 759             } else {
 760                 state = 2;
 761                 --src; // unread !!!
 762             }
 763
 764         } else {
 765
 766                         // within ident mode
 767                         if (isIdentChar(c)) {
 768                                 *id++ = c;
 769                         } else {
 770                                 *id = 0;
 771                                 dst = writeIdentValue(dst, format, ident, visited, localValEnv);
 772                                 state = 0;
 773                                 src -= 1;
 774                         }
 775                 }
 776         }
 777
 778         if (state == 2) {
 779                 *id = 0;
 780                 dst = writeIdentValue(dst, format, ident, visited, localValEnv);
 781         }
 782         *dst = 0;
 783         return (parametric) ? strdup(res) : label;
 784 }
 785
 786
 787
 788 /**
 789  * Iterate a parallel construction
 790  *
 791  * Iterate a parallel construction such that :
 792  * par(i,10,E) --> E(i<-0),(E(i<-1),...,E(i<-9))
 793  * @param id the formal parameter of the iteration
 794  * @param num the number of iterartions
 795  * @param body the body expression of the iteration
 796  * @param globalDefEnv the global environment
 797  * @param visited list of visited definition to detect recursive definitions
 798  * @param localValEnv the local environment
 799  * @return a block diagram in normal form
 800  */
 801 static Tree iteratePar (Tree id, int num, Tree body, Tree visited, Tree localValEnv)
 802 {
 803     assert (num>0);
 804
 805     Tree res = eval(body, visited, pushValueDef(id, tree(num-1), localValEnv));
 806     for (int i = num-2; i >= 0; i--) {
 807         res = boxPar(eval(body, visited, pushValueDef(id, tree(i), localValEnv)), res);
 808     }
 809
 810     return res;
 811 }
 812
 813
 814
 815 /**
 816  * Iterate a sequential construction
 817  *
 818  * Iterate a sequential construction such that :
 819  * seq(i,10,E) --> E(i<-0):(E(i<-1):...:E(i<-9))
 820  * @param id the formal parameter of the iteration
 821  * @param num the number of iterartions
 822  * @param body the body expression of the iteration
 823  * @param globalDefEnv the global environment
 824  * @param visited list of visited definition to detect recursive definitions
 825  * @return a block diagram in normal form
 826  */
 827 static Tree iterateSeq (Tree id, int num, Tree body, Tree visited, Tree localValEnv)
 828 {
 829         assert (num>0);
 830
 831     Tree res = eval(body, visited, pushValueDef(id, tree(num-1), localValEnv));
 832     for (int i = num-2; i >= 0; i--) {
 833         res = boxSeq(eval(body, visited, pushValueDef(id, tree(i), localValEnv)), res);
 834     }
 835
 836         return res;
 837 }
 838
 839
 840
 841 /**
 842  * Iterate an addition construction
 843  *
 844  * Iterate an addition construction such that :
 845  * par(i,10,E) --> E(i<-0)+E(i<-1)+...+E(i<-9)
 846  * @param id the formal parameter of the iteration
 847  * @param num the number of iterartions
 848  * @param body the body expression of the iteration
 849  * @param globalDefEnv the global environment
 850  * @param visited list of visited definition to detect recursive definitions
 851  * @param localValEnv the local environment
 852  * @return a block diagram in normal form
 853  */
 854 static Tree iterateSum (Tree id, int num, Tree body, Tree visited, Tree localValEnv)
 855 {
 856         assert (num>0);
 857
 858         Tree res = eval(body, visited, pushValueDef(id, tree(0), localValEnv));
 859
 860         for (int i = 1; i < num; i++) {
 861                 res = boxSeq(boxPar(res, eval(body, visited, pushValueDef(id, tree(i), localValEnv))),boxPrim2(sigAdd)) ;
 862         }
 863
 864         return res;
 865 }
 866
 867
 868
 869 /**
 870  * Iterate a product construction
 871  *
 872  * Iterate a product construction such that :
 873  * par(i,10,E) --> E(i<-0)*E(i<-1)*...*E(i<-9)
 874  * @param id the formal parameter of the iteration
 875  * @param num the number of iterartions
 876  * @param body the body expression of the iteration
 877  * @param globalDefEnv the global environment
 878  * @param visited list of visited definition to detect recursive definitions
 879  * @param localValEnv the local environment
 880  * @return a block diagram in normal form
 881  */
 882 static Tree iterateProd (Tree id, int num, Tree body, Tree visited, Tree localValEnv)
 883 {
 884         assert (num>0);
 885
 886         Tree res = eval(body, visited, pushValueDef(id, tree(0), localValEnv));
 887
 888         for (int i = 1; i < num; i++) {
 889                 res = boxSeq(boxPar(res, eval(body, visited, pushValueDef(id, tree(i), localValEnv))),boxPrim2(sigMul)) ;
 890         }
 891
 892         return res;
 893 }
 894
 895 /**
 896  * Compute the sum of outputs of a list of boxes. The sum is
 897  * valid if all the boxes have a valid boxType
 898  *
 899  * @param boxlist the list of boxes
 900  * @param outputs sum of outputs of the boxes
 901  * @return true if outputs is valid, false otherwise
 902  */
 903  #if 1
 904 static bool boxlistOutputs(Tree boxlist, int* outputs)
 905 {
 906     int ins, outs;
 907
 908     *outputs = 0;
 909     while (!isNil(boxlist))
 910     {
 911         Tree b = a2sb(hd(boxlist)); // for getBoxType, suppose list of evaluated boxes
 912         if (getBoxType(b, &ins, &outs)) {
 913             *outputs += outs;
 914         } else {
 915                 // arbitrary output arity set to 1
 916                 // when can't be determined
 917                 *outputs += 1;
 918         }
 919         boxlist = tl(boxlist);
 920     }
 921     return isNil(boxlist);
 922 }
 923 #else
 924 static bool boxlistOutputs(Tree boxlist, int* outputs)
 925 {
 926     int ins, outs;
 927
 928     *outputs = 0;
 929     while (!isNil(boxlist) && getBoxType(hd(boxlist), &ins, &outs)) {
 930             *outputs += outs;
 931             boxlist = tl(boxlist);
 932     }
 933     return isNil(boxlist);
 934 }
 935 #endif
 936
 937 /**
 938  * repeat n times a wire
 939  */
 940 static Tree nwires(int n)
 941 {
 942         Tree l = nil;
 943         while (n--) { l = cons(boxWire(), l); }
 944         return l;
 945 }
 946
 947
 948 /**
 949  * Apply a function to a list of arguments.
 950  * Apply a function F to a list of arguments (a,b,c,...).
 951  * F can be either a closure over an abstraction, or a
 952  * pattern matcher. If it is not the case then we have :
 953  * F(a,b,c,...) ==> (a,b,c,...):F
 954  *
 955  * @param fun the function to apply
 956  * @param larg the list of arguments
 957  * @return the resulting expression in normal form
 958  */
 959 static Tree applyList (Tree fun, Tree larg)
 960 {
 961         Tree abstr;
 962         Tree globalDefEnv;
 963         Tree visited;
 964         Tree localValEnv;
 965         Tree envList;
 966         Tree originalRules;
 967         Tree revParamList;
 968
 969         Tree id;
 970         Tree body;
 971
 972         Automaton*      automat;
 973         int                     state;
 974
 975         prim2   p2;
 976
 977     //cerr << "applyList (" << *fun << ", " << *larg << ")" << endl;
 978
 979         if (isNil(larg)) return fun;
 980
 981         if (isBoxError(fun) || isBoxError(larg)) {
 982                 return boxError();
 983         }
 984
 985         if (isBoxPatternMatcher(fun, automat, state, envList, originalRules, revParamList)) {
 986                 Tree                    result;
 987                 int                     state2;
 988                 vector<Tree>    envVect;
 989
 990                 list2vec(envList, envVect);
 991         //cerr << "applyList/apply_pattern_matcher(" << automat << "," << state << "," << *hd(larg) << ")" << endl;
 992                 state2 = apply_pattern_matcher(automat, state, hd(larg), result, envVect);
 993         //cerr << "state2 = " << state2 << "; result = " << *result << endl;
 994                 if (state2 >= 0 && isNil(result)) {
 995                         // we need to continue the pattern matching
 996                         return applyList(
 997                                                 boxPatternMatcher(automat, state2, vec2list(envVect), originalRules, cons(hd(larg),revParamList)),
 998                                                 tl(larg) );
 999                 } else if (state2 < 0) {
1000                         cerr << "ERROR : pattern matching failed, no rule of " << boxpp(boxCase(originalRules))
1001                                  << " matches argument list " << boxpp(reverse(cons(hd(larg), revParamList))) << endl;
1002                         exit(1);
1003                 } else {
1004                         // Pattern Matching was succesful
1005                         // the result is a closure that we need to evaluate.
1006                         if (isClosure(result, body, globalDefEnv, visited, localValEnv)) {
1007                                 // why ??? return simplifyPattern(eval(body, nil, localValEnv));
1008                                 //return eval(body, nil, localValEnv);
1009                                 return applyList(eval(body, nil, localValEnv), tl(larg));
1010                         } else {
1011                                 cerr << "wrong result from pattern matching (not a closure) : " << boxpp(result) << endl;
1012                                 return boxError();
1013                         }
1014                 }
1015         }
1016         if (!isClosure(fun, abstr, globalDefEnv, visited, localValEnv)) {
1017                 // principle : f(a,b,c,...) ==> (a,b,c,...):f
1018          int ins, outs;
1019
1020          // check arity of function
1021          Tree efun = a2sb(fun);
1022          //cerr << "TRACEPOINT 1 : " << boxpp(efun) << endl;
1023          if (!getBoxType(efun, &ins, &outs)) { // on laisse comme ca pour le moment
1024                 // we can't determine the input arity of the expression
1025                 // hope for the best
1026                 return boxSeq(larg2par(larg), fun);
1027          }
1028
1029          // check arity of arg list
1030          if (!boxlistOutputs(larg,&outs)) {
1031                 // we don't know yet the output arity of larg. Therefore we can't
1032                 // do any arity checking nor add _ to reach the required number of arguments
1033             // cerr << "warning : can't infere the type of : " << boxpp(larg) << endl;
1034                 return boxSeq(larg2par(larg), fun);
1035          }
1036
1037                 if (outs > ins) {
1038                         cerr << "too much arguments : " << outs << ", instead of : " << ins << endl;
1039             cerr << "when applying : " << boxpp(fun) << endl
1040                  << "           to : " << boxpp(larg) << endl;
1041                         assert(false);
1042                 }
1043
1044         if (    (outs == 1)
1045             &&
1046                 (  ( isBoxPrim2(fun, &p2) && (p2 != sigPrefix) )
1047                 || ( getUserData(fun) && ((xtended*)getUserData(fun))->isSpecialInfix() ) ) ) {
1048             // special case : /(3) ==> _,3 : /
1049             Tree larg2 = concat(nwires(ins-outs), larg);
1050             return boxSeq(larg2par(larg2), fun);
1051
1052         } else {
1053
1054                         Tree larg2 = concat(larg, nwires(ins-outs));
1055             return boxSeq(larg2par(larg2), fun);
1056         }
1057         }
1058
1059     if (isBoxEnvironment(abstr)) {
1060         evalerrorbox(yyfilename, -1, "an environment can't be used as a function", fun);
1061         exit(1);
1062     }
1063
1064     if (!isBoxAbstr(abstr, id, body)) {
1065         evalerror(yyfilename, -1, "(internal) not an abstraction inside closure", fun);
1066         exit(1);
1067     }
1068
1069         // try to synthetise a  name from the function name and the argument name
1070         {
1071                 Tree arg = eval(hd(larg), visited, localValEnv);
1072                 Tree narg; if ( isBoxNumeric(arg,narg) ) { arg =  narg; }
1073                 Tree f = eval(body, visited, pushValueDef(id, arg, localValEnv));
1074
1075                 Tree    fname;
1076                 if (getDefNameProperty(fun, fname)) {
1077                         stringstream s; s << tree2str(fname); if (!gSimpleNames) s << "(" << boxpp(arg) << ")";
1078                         setDefNameProperty(f, s.str());
1079                 }
1080                 return applyList(f, tl(larg));
1081         }
1082 }
1083
1084
1085
1086 /**
1087  * Eval a list of expression in reverse order
1088  *
1089  * Eval a list of expressions returning the list of results in reverse order.
1090  *
1091  * @param lexp list of expressions to evaluate
1092  * @param globalDefEnv the global environment
1093  * @param visited list of visited definition to detect recursive definitions
1094  * @param localValEnv the local environment
1095  * @return list of evaluated expressions in reverse order
1096  */
1097 static Tree revEvalList (Tree lexp, Tree visited, Tree localValEnv)
1098 {
1099     Tree result = nil;
1100     //Tree lexp_orig = lexp;
1101     //cerr << "ENTER revEvalList(" << *lexp_orig << ", env:" << *localValEnv << ")" << endl;
1102     while (!isNil(lexp)) {
1103                 result = cons(eval(hd(lexp), visited, localValEnv), result);
1104                 lexp = tl(lexp);
1105         }
1106
1107     //cerr << "EXIT revEvalList(" << *lexp_orig << ", env:" << *localValEnv << ") -> " << *result << endl;
1108         return result;
1109 }
1110
1111
1112
1113 /**
1114  * Transform a list of expressions in a parallel construction
1115  *
1116  * @param larg list of expressions
1117  * @return parallel construction
1118  */
1119 static Tree larg2par (Tree larg)
1120 {
1121         if (isNil(larg)) {
1122                 evalerror(yyfilename, -1, "empty list of arguments", larg);
1123                 exit(1);
1124         }
1125         if (isNil(tl(larg))) {
1126                 return hd(larg);
1127         }
1128         return boxPar(hd(larg), larg2par(tl(larg)));
1129 }
1130
1131
1132
1133
1134 /**
1135  * Search the environment for the definition of a symbol
1136  * ID and evaluate it. Detects recursive definitions using
1137  * a set of visited IDxENV. Associates the symbol as a definition name
1138  * property of the definition.
1139  * @param id the symbol ID t-o search
1140  * @param visited set of visited symbols (used for recursive definition detection)
1141  * @param lenv the environment where to search
1142  * @return the evaluated definition of ID
1143  */
1144 static Tree evalIdDef(Tree id, Tree visited, Tree lenv)
1145 {
1146         Tree def, name;
1147
1148         // search the environment env for a definition of symbol id
1149         while (!isNil(lenv) && !getProperty(lenv, id, def)) {
1150                 lenv = lenv->branch(0);
1151         }
1152
1153         // check that the definition exists
1154         if (isNil(lenv)) {
1155         cerr << "undefined symbol " << *id << endl;
1156                 evalerror(getDefFileProp(id), getDefLineProp(id), "undefined symbol ", id);
1157                 exit(1);
1158         }
1159
1160     //cerr << "Id definition is " << *def << endl;
1161         // check that it is not a recursive definition
1162         Tree p = cons(id,lenv);
1163         // set the definition name property
1164         if (!getDefNameProperty(def, name)) {
1165                 // if the definition has no name use the identifier
1166                 stringstream s; s << boxpp(id);
1167                 //XXXXXX setDefNameProperty(def, s.str());
1168         }
1169
1170         // return the evaluated definition
1171         return eval(def, addElement(p,visited), nil);
1172 }
1173
1174
1175 /**
1176  * Creates a list of n elements.
1177  * @param n number of elements
1178  * @param e element to be repeated
1179  * @return [e e e ...] n times
1180  */
1181
1182 static Tree listn (int n, Tree e)
1183 {
1184         return (n<= 0) ? nil : cons(e, listn(n-1,e));
1185 }
1186
1187 /**
1188  * A property to store the pattern matcher corresponding to a set of rules
1189  * in a specific environement
1190  */
1191
1192 static Node PMPROPERTYNODE(symbol("PMPROPERTY"));
1193
1194 static void setPMProperty(Tree t, Tree env, Tree pm)
1195 {
1196         setProperty(t, tree(PMPROPERTYNODE, env), pm);
1197 }
1198
1199 static bool getPMProperty(Tree t, Tree env, Tree& pm)
1200 {
1201         return getProperty(t, tree(PMPROPERTYNODE, env), pm);
1202 }
1203
1204 /**
1205  * Eval a case expression containing a list of pattern matching rules.
1206  * Creates a boxPatternMatcher containing a pm autamaton a state
1207  * and a list of environments.
1208  * @param rules the list of rules
1209  * @param env the environment uused to evaluate the patterns and closure the rhs
1210  * @return a boxPatternMatcher ready to be applied
1211  */
1212
1213 static Tree     evalCase(Tree rules, Tree env)
1214 {
1215         Tree pm;
1216         if (!getPMProperty(rules, env, pm)) {
1217                 Automaton*      a = make_pattern_matcher(evalRuleList(rules, env));
1218         pm = boxPatternMatcher(a, 0, listn(len(rules), pushEnvBarrier(env)), rules, nil);
1219         setPMProperty(rules, env, pm);
1220         }
1221         return pm;
1222 }
1223
1224
1225 /**
1226  * Evaluates each rule of the list
1227  */
1228 static Tree     evalRuleList(Tree rules, Tree env)
1229 {
1230     //cerr << "evalRuleList "<< *rules << " in " << *env << endl;
1231         if (isNil(rules)) return nil;
1232         else return cons(evalRule(hd(rules), env), evalRuleList(tl(rules), env));
1233 }
1234
1235
1236 /**
1237  * Evaluates the list of patterns and closure the rhs
1238  */
1239 static Tree     evalRule(Tree rule, Tree env)
1240 {
1241     //cerr << "evalRule "<< *rule << " in " << *env << endl;
1242         return cons(evalPatternList(left(rule), env), right(rule));
1243 }
1244
1245
1246 /**
1247  * Evaluates each pattern of the list
1248  */
1249 static Tree     evalPatternList(Tree patterns, Tree env)
1250 {
1251         if (isNil(patterns)) {
1252                 return nil;
1253         } else {
1254                 return cons(    evalPattern(hd(patterns), env),
1255                                                 evalPatternList(tl(patterns), env)  );
1256         }
1257 }
1258
1259
1260 /**
1261  * Evaluates a pattern and simplify it to numerical value
1262  * if possible
1263  */
1264 static Tree     evalPattern(Tree pattern, Tree env)
1265 {
1266     Tree p = eval(pattern, nil, env);
1267     return patternSimplification(p);
1268 }
1269
1270
1271 static void list2vec(Tree l, vector<Tree>& v)
1272 {
1273         while (!isNil(l)) {
1274                 v.push_back(hd(l));
1275                 l = tl(l);
1276         }
1277 }
1278
1279
1280 static Tree vec2list(const vector<Tree>& v)
1281 {
1282         Tree l = nil;
1283         int      n = v.size();
1284         while (n--) { l = cons(v[n],l); }
1285         return l;
1286 }
1287
1288
1289
1290
1291 /////////////////////////////////////////////////////////////////////////////////////////////////////////
1292 // further simplification : replace bloc-diagrams that denote constant number by this number
1293 /////////////////////////////////////////////////////////////////////////////////////////////////////////
1294
1295 static property<Tree> SimplifiedBoxProperty;
1296 static Tree numericBoxSimplification(Tree box);
1297 static Tree insideBoxSimplification (Tree box);
1298
1299 /**
1300  * boxSimplification(box) : simplify a block-diagram by replacing expressions
1301  * denoting a constant number by this number.
1302  */
1303 Tree boxSimplification (Tree box)
1304 {
1305     Tree    simplified;
1306
1307     if (SimplifiedBoxProperty.get(box,simplified)) {
1308
1309         return simplified;
1310
1311     } else {
1312
1313         simplified = numericBoxSimplification(box);
1314
1315         // transferts name property if any
1316         Tree name; if (getDefNameProperty(box, name)) setDefNameProperty(simplified, name);
1317
1318         // attach simplified expression as a property of original box
1319         SimplifiedBoxProperty.set(box,simplified);
1320
1321         return simplified;
1322     }
1323 }
1324
1325 /**
1326  * Try to do a numeric simplification of a block-diagram
1327  */
1328 Tree numericBoxSimplification(Tree box)
1329 {
1330     int     ins, outs;
1331     Tree    result;
1332     int     i;
1333     double  x;
1334
1335     if ( ! getBoxType(box, &ins, &outs)) {
1336         cout << "ERROR in file " << __FILE__ << ':' << __LINE__ << ", Can't compute the box type of : " << *box << endl;
1337         exit(1);
1338     }
1339
1340     if (ins==0 && outs==1) {
1341         // this box can potentially denote a number
1342         if (isBoxInt(box, &i) || isBoxReal(box, &x)) {
1343            result = box;
1344         } else {
1345             // propagate signals to discover if it simplifies to a number
1346             int     i;
1347             double  x;
1348             Tree    lsignals = boxPropagateSig(nil, box , makeSigInputList(0));
1349             Tree    s = simplify(hd(lsignals));
1350
1351             if (isSigReal(s, &x))       {
1352                 result = boxReal(x);
1353             } else if (isSigInt(s, &i))         {
1354                 result = boxInt(i);
1355             } else {
1356                 result = insideBoxSimplification(box);
1357             }
1358         }
1359     } else {
1360         // this box can't denote a number
1361         result = insideBoxSimplification(box);
1362     }
1363     return result;
1364 }
1365
1366 /**
1367  *  Simplify inside a block-diagram : S[A*B] => S[A]*S[B]
1368  */
1369 Tree insideBoxSimplification (Tree box)
1370 {
1371     int         i;
1372     double      r;
1373     prim0       p0;
1374     prim1       p1;
1375     prim2       p2;
1376     prim3       p3;
1377     prim4       p4;
1378     prim5       p5;
1379
1380     Tree        t1, t2, ff, label, cur, min, max, step, type, name, file, slot, body;
1381
1382
1383     xtended* xt = (xtended*)getUserData(box);
1384
1385     // Extended Primitives
1386
1387     if (xt)     {
1388         return box;
1389     }
1390
1391     // Numbers and Constants
1392
1393     else if (isBoxInt(box, &i))         {
1394         return box;
1395     }
1396     else if (isBoxReal(box, &r))        {
1397         return box;
1398     }
1399
1400     else if (isBoxFConst(box, type, name, file))    {
1401         return box;
1402     }
1403
1404     else if (isBoxFVar(box, type, name, file))    {
1405         return box;
1406     }
1407
1408     // Wire and Cut
1409
1410     else if (isBoxCut(box))                             {
1411         return box;
1412     }
1413
1414     else if (isBoxWire(box))                            {
1415         return box;
1416     }
1417
1418     // Primitives
1419
1420     else if (isBoxPrim0(box, &p0))                      {
1421         return box;
1422     }
1423
1424     else if (isBoxPrim1(box, &p1))                      {
1425         return box;
1426     }
1427
1428     else if (isBoxPrim2(box, &p2))                              {
1429         return box;
1430     }
1431
1432     else if (isBoxPrim3(box, &p3))                              {
1433         return box;
1434     }
1435
1436     else if (isBoxPrim4(box, &p4))                              {
1437         return box;
1438     }
1439
1440     else if (isBoxPrim5(box, &p5))                              {
1441         return box;
1442     }
1443
1444     else if (isBoxFFun(box, ff))                                {
1445         return box;
1446     }
1447
1448     // User Interface Widgets
1449
1450     else if (isBoxButton(box, label))   {
1451         return box;
1452     }
1453
1454     else if (isBoxCheckbox(box, label))         {
1455         return box;
1456     }
1457
1458     else if (isBoxVSlider(box, label, cur, min, max, step))     {
1459         return box;
1460     }
1461
1462     else if (isBoxHSlider(box, label, cur, min, max, step))     {
1463         return box;
1464     }
1465
1466     else if (isBoxNumEntry(box, label, cur, min, max, step))    {
1467         return box;
1468     }
1469
1470     else if (isBoxVBargraph(box, label, min, max))      {
1471         return box;
1472     }
1473
1474     else if (isBoxHBargraph(box, label, min, max))      {
1475         return box;
1476     }
1477
1478     // User Interface Groups
1479
1480     else if (isBoxVGroup(box, label, t1))       {
1481         return boxVGroup(label, boxSimplification(t1));
1482     }
1483
1484     else if (isBoxHGroup(box, label, t1))       {
1485         return boxHGroup(label, boxSimplification(t1));
1486     }
1487
1488     else if (isBoxTGroup(box, label, t1))       {
1489         return boxTGroup(label, boxSimplification(t1));
1490     }
1491
1492     // Slots and Symbolic Boxes
1493
1494     else if (isBoxSlot(box))                            {
1495         return box;;
1496     }
1497
1498     else if (isBoxSymbolic(box, slot, body)){
1499
1500         Tree b = boxSimplification(body);
1501         return boxSymbolic(slot,b);
1502     }
1503
1504     // Block Diagram Composition Algebra
1505
1506     else if (isBoxSeq(box, t1, t2))     {
1507         Tree s1 = boxSimplification(t1);
1508         Tree s2 = boxSimplification(t2);
1509         return boxSeq(s1,s2);
1510     }
1511
1512     else if (isBoxPar(box, t1, t2))     {
1513         Tree s1 = boxSimplification(t1);
1514         Tree s2 = boxSimplification(t2);
1515         return boxPar(s1,s2);
1516     }
1517
1518     else if (isBoxSplit(box, t1, t2))   {
1519         Tree s1 = boxSimplification(t1);
1520         Tree s2 = boxSimplification(t2);
1521         return boxSplit(s1,s2);
1522     }
1523
1524     else if (isBoxMerge(box, t1, t2))   {
1525         Tree s1 = boxSimplification(t1);
1526         Tree s2 = boxSimplification(t2);
1527         return boxMerge(s1,s2);
1528     }
1529     else if (isBoxRec(box, t1, t2))     {
1530         Tree s1 = boxSimplification(t1);
1531         Tree s2 = boxSimplification(t2);
1532         return boxRec(s1,s2);
1533     }
1534
1535     cout << "ERROR in file " << __FILE__ << ':' << __LINE__ << ", unrecognised box expression : " << *box << endl;
1536     exit(1);
1537     return 0;
1538 }