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GeezerVison is showing github.com — solvespace/src/expr.cpp at python · realthunder/solvespace Expand file tree/ Copy pathexpr.cppMore file actions 844 lines (722 loc) · 21.7 KB / Copy pathexpr.cppFile metadata and controls844 lines (722 loc) · 21.7 KB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 //----------------------------------------------------------------------------- // The symbolic algebra system used to write our constraint equations; // routines to build expressions in software or from a user-provided string, // and to compute the partial derivatives that we'll use when write our // Jacobian matrix. // // Copyright 2008-2013 Jonathan Westhues. //----------------------------------------------------------------------------- #include <array> #include <list> #include "solvespace.h" ExprVector ExprVector::From(Expr *x, Expr *y, Expr *z) { ExprVector r = { x, y, z}; return r; } ExprVector ExprVector::From(Vector vn) { ExprVector ve; ve.x = Expr::From(vn.x); ve.y = Expr::From(vn.y); ve.z = Expr::From(vn.z); return ve; } ExprVector ExprVector::From(hParam x, hParam y, hParam z) { ExprVector ve; ve.x = Expr::From(x); ve.y = Expr::From(y); ve.z = Expr::From(z); return ve; } ExprVector ExprVector::From(double x, double y, double z) { ExprVector ve; ve.x = Expr::From(x); ve.y = Expr::From(y); ve.z = Expr::From(z); return ve; } ExprVector ExprVector::Minus(ExprVector b) { ExprVector r; r.x = x->Minus(b.x); r.y = y->Minus(b.y); r.z = z->Minus(b.z); return r; } ExprVector ExprVector::Plus(ExprVector b) { ExprVector r; r.x = x->Plus(b.x); r.y = y->Plus(b.y); r.z = z->Plus(b.z); return r; } Expr *ExprVector::Dot(ExprVector b) { Expr *r; r = x->Times(b.x); r = r->Plus(y->Times(b.y)); r = r->Plus(z->Times(b.z)); return r; } ExprVector ExprVector::Cross(ExprVector b) { ExprVector r; r.x = (y->Times(b.z))->Minus(z->Times(b.y)); r.y = (z->Times(b.x))->Minus(x->Times(b.z)); r.z = (x->Times(b.y))->Minus(y->Times(b.x)); return r; } ExprVector ExprVector::ScaledBy(Expr *s) { ExprVector r; r.x = x->Times(s); r.y = y->Times(s); r.z = z->Times(s); return r; } ExprVector ExprVector::WithMagnitude(Expr *s) { Expr *m = Magnitude(); return ScaledBy(s->Div(m)); } Expr *ExprVector::Magnitude(void) { Expr *r; r = x->Square(); r = r->Plus(y->Square()); r = r->Plus(z->Square()); return r->Sqrt(); } Vector ExprVector::Eval(void) { Vector r; r.x = x->Eval(); r.y = y->Eval(); r.z = z->Eval(); return r; } ExprQuaternion ExprQuaternion::From(hParam w, hParam vx, hParam vy, hParam vz) { ExprQuaternion q; q.w = Expr::From(w); q.vx = Expr::From(vx); q.vy = Expr::From(vy); q.vz = Expr::From(vz); return q; } ExprQuaternion ExprQuaternion::From(Expr *w, Expr *vx, Expr *vy, Expr *vz) { ExprQuaternion q; q.w = w; q.vx = vx; q.vy = vy; q.vz = vz; return q; } ExprQuaternion ExprQuaternion::From(Quaternion qn) { ExprQuaternion qe; qe.w = Expr::From(qn.w); qe.vx = Expr::From(qn.vx); qe.vy = Expr::From(qn.vy); qe.vz = Expr::From(qn.vz); return qe; } ExprVector ExprQuaternion::RotationU(void) { ExprVector u; Expr *two = Expr::From(2); u.x = w->Square(); u.x = (u.x)->Plus(vx->Square()); u.x = (u.x)->Minus(vy->Square()); u.x = (u.x)->Minus(vz->Square()); u.y = two->Times(w->Times(vz)); u.y = (u.y)->Plus(two->Times(vx->Times(vy))); u.z = two->Times(vx->Times(vz)); u.z = (u.z)->Minus(two->Times(w->Times(vy))); return u; } ExprVector ExprQuaternion::RotationV(void) { ExprVector v; Expr *two = Expr::From(2); v.x = two->Times(vx->Times(vy)); v.x = (v.x)->Minus(two->Times(w->Times(vz))); v.y = w->Square(); v.y = (v.y)->Minus(vx->Square()); v.y = (v.y)->Plus(vy->Square()); v.y = (v.y)->Minus(vz->Square()); v.z = two->Times(w->Times(vx)); v.z = (v.z)->Plus(two->Times(vy->Times(vz))); return v; } ExprVector ExprQuaternion::RotationN(void) { ExprVector n; Expr *two = Expr::From(2); n.x = two->Times( w->Times(vy)); n.x = (n.x)->Plus (two->Times(vx->Times(vz))); n.y = two->Times(vy->Times(vz)); n.y = (n.y)->Minus(two->Times( w->Times(vx))); n.z = w->Square(); n.z = (n.z)->Minus(vx->Square()); n.z = (n.z)->Minus(vy->Square()); n.z = (n.z)->Plus (vz->Square()); return n; } ExprVector ExprQuaternion::Rotate(ExprVector p) { // Express the point in the new basis return (RotationU().ScaledBy(p.x)).Plus( RotationV().ScaledBy(p.y)).Plus( RotationN().ScaledBy(p.z)); } ExprQuaternion ExprQuaternion::Times(ExprQuaternion b) { Expr *sa = w, *sb = b.w; ExprVector va = { vx, vy, vz }; ExprVector vb = { b.vx, b.vy, b.vz }; ExprQuaternion r; r.w = (sa->Times(sb))->Minus(va.Dot(vb)); ExprVector vr = vb.ScaledBy(sa).Plus( va.ScaledBy(sb).Plus( va.Cross(vb))); r.vx = vr.x; r.vy = vr.y; r.vz = vr.z; return r; } Expr *ExprQuaternion::Magnitude(void) { return ((w ->Square())->Plus( (vx->Square())->Plus( (vy->Square())->Plus( (vz->Square())))))->Sqrt(); } struct ExprChunk { std::array<Expr,8192> chunk; size_t count; bool full() { return count==chunk.size(); } Expr *get() { return &chunk[count++]; } ExprChunk() :count(0) {} }; static std::list<ExprChunk> _ExprMem(1); static auto _ExprMemIt = _ExprMem.begin(); Expr *Expr::AllocExpr() { if(_ExprMemIt->full()) { if(++_ExprMemIt == _ExprMem.end()) { _ExprMem.emplace_back(); --_ExprMemIt; } } return _ExprMemIt->get(); } void Expr::FreeAll() { for(auto &v : _ExprMem) v.count = 0; _ExprMemIt = _ExprMem.begin(); } Expr *Expr::From(hParam p) { Expr *r = AllocExpr(); r->op = PARAM; r->parh = p; return r; } Expr *Expr::From(double v) { // Statically allocate common constants. // Note: this is only valid because AllocExpr() uses AllocTemporary(), // and Expr* is never explicitly freed. if(v == 0.0) { static Expr zero(0.0); return &zero; } if(v == 1.0) { static Expr one(1.0); return &one; } if(v == -1.0) { static Expr mone(-1.0); return &mone; } if(v == 0.5) { static Expr half(0.5); return ½ } if(v == -0.5) { static Expr mhalf(-0.5); return &mhalf; } Expr *r = AllocExpr(); r->op = CONSTANT; r->v = v; return r; } Expr *Expr::AnyOp(int newOp, Expr *b) { Expr *r = AllocExpr(); r->op = newOp; r->a = this; r->b = b; return r; } int Expr::Children(void) { switch(op) { case PARAM: case PARAM_PTR: case CONSTANT: return 0; case PLUS: case MINUS: case TIMES: case DIV: return 2; case NEGATE: case SQRT: case SQUARE: case SIN: case COS: case ASIN: case ACOS: return 1; default: oops(); } } int Expr::Nodes(void) { switch(Children()) { case 0: return 1; case 1: return 1 + a->Nodes(); case 2: return 1 + a->Nodes() + b->Nodes(); default: oops(); } } Expr *Expr::DeepCopy(void) { Expr *n = AllocExpr(); *n = *this; int c = n->Children(); if(c > 0) n->a = a->DeepCopy(); if(c > 1) n->b = b->DeepCopy(); return n; } Expr *Expr::DeepCopyWithParamsAsPointers(IdList<Param,hParam> *firstTry, IdList<Param,hParam> *thenTry) { Expr *n = AllocExpr(); if(op == PARAM) { // A param that is referenced by its hParam gets rewritten to go // straight in to the parameter table with a pointer, or simply // into a constant if it's already known. Param *p = firstTry->FindByIdNoOops(parh); if(!p) p = thenTry->FindById(parh); if(p->known) { n->op = CONSTANT; n->v = p->val; } else { n->op = PARAM_PTR; n->parp = p; } return n; } *n = *this; int c = n->Children(); if(c > 0) n->a = a->DeepCopyWithParamsAsPointers(firstTry, thenTry); if(c > 1) n->b = b->DeepCopyWithParamsAsPointers(firstTry, thenTry); return n; } double Expr::Eval(void) { switch(op) { case PARAM: return SK.GetParam(parh)->val; case PARAM_PTR: return parp->val; case CONSTANT: return v; case PLUS: return a->Eval() + b->Eval(); case MINUS: return a->Eval() - b->Eval(); case TIMES: return a->Eval() * b->Eval(); case DIV: return a->Eval() / b->Eval(); case NEGATE: return -(a->Eval()); case SQRT: return sqrt(a->Eval()); case SQUARE: { double r = a->Eval(); return r*r; } case SIN: return sin(a->Eval()); case COS: return cos(a->Eval()); case ACOS: return acos(a->Eval()); case ASIN: return asin(a->Eval()); default: oops(); } } Expr *Expr::PartialWrt(hParam p) { Expr *da, *db; switch(op) { case PARAM_PTR: return From(p.v == parp->h.v ? 1 : 0); case PARAM: return From(p.v == parh.v ? 1 : 0); case CONSTANT: return From(0.0); case PLUS: return (a->PartialWrt(p))->Plus(b->PartialWrt(p)); case MINUS: return (a->PartialWrt(p))->Minus(b->PartialWrt(p)); case TIMES: da = a->PartialWrt(p); db = b->PartialWrt(p); return (a->Times(db))->Plus(b->Times(da)); case DIV: da = a->PartialWrt(p); db = b->PartialWrt(p); return ((da->Times(b))->Minus(a->Times(db)))->Div(b->Square()); case SQRT: return (From(0.5)->Div(a->Sqrt()))->Times(a->PartialWrt(p)); case SQUARE: return (From(2.0)->Times(a))->Times(a->PartialWrt(p)); case NEGATE: return (a->PartialWrt(p))->Negate(); case SIN: return (a->Cos())->Times(a->PartialWrt(p)); case COS: return ((a->Sin())->Times(a->PartialWrt(p)))->Negate(); case ASIN: return (From(1)->Div((From(1)->Minus(a->Square()))->Sqrt())) ->Times(a->PartialWrt(p)); case ACOS: return (From(-1)->Div((From(1)->Minus(a->Square()))->Sqrt())) ->Times(a->PartialWrt(p)); default: oops(); } } uint64_t Expr::ParamsUsed(void) { uint64_t r = 0; if(op == PARAM) r |= ((uint64_t)1 << (parh.v % 61)); if(op == PARAM_PTR) r |= ((uint64_t)1 << (parp->h.v % 61)); int c = Children(); if(c >= 1) r |= a->ParamsUsed(); if(c >= 2) r |= b->ParamsUsed(); return r; } bool Expr::DependsOn(hParam p) { if(op == PARAM) return (parh.v == p.v); if(op == PARAM_PTR) return (parp->h.v == p.v); int c = Children(); if(c == 1) return a->DependsOn(p); if(c == 2) return a->DependsOn(p) || b->DependsOn(p); return false; } bool Expr::Tol(double a, double b) { return fabs(a - b) < 0.001; } Expr *Expr::FoldConstants(void) { Expr *n = AllocExpr(); *n = *this; int c = Children(); if(c >= 1) n->a = a->FoldConstants(); if(c >= 2) n->b = b->FoldConstants(); switch(op) { case PARAM_PTR: case PARAM: case CONSTANT: break; case MINUS: case TIMES: case DIV: case PLUS: // If both ops are known, then we can evaluate immediately if(n->a->op == CONSTANT && n->b->op == CONSTANT) { double nv = n->Eval(); n->op = CONSTANT; n->v = nv; break; } // x + 0 = 0 + x = x if(op == PLUS && n->b->op == CONSTANT && Tol(n->b->v, 0)) { *n = *(n->a); break; } if(op == PLUS && n->a->op == CONSTANT && Tol(n->a->v, 0)) { *n = *(n->b); break; } // 1*x = x*1 = x if(op == TIMES && n->b->op == CONSTANT && Tol(n->b->v, 1)) { *n = *(n->a); break; } if(op == TIMES && n->a->op == CONSTANT && Tol(n->a->v, 1)) { *n = *(n->b); break; } // 0*x = x*0 = 0 if(op == TIMES && n->b->op == CONSTANT && Tol(n->b->v, 0)) { n->op = CONSTANT; n->v = 0; break; } if(op == TIMES && n->a->op == CONSTANT && Tol(n->a->v, 0)) { n->op = CONSTANT; n->v = 0; break; } break; case SQRT: case SQUARE: case NEGATE: case SIN: case COS: case ASIN: case ACOS: if(n->a->op == CONSTANT) { double nv = n->Eval(); n->op = CONSTANT; n->v = nv; } break; default: oops(); } return n; } void Expr::Substitute(hParam oldh, hParam newh) { if(op == PARAM_PTR) oops(); if(op == PARAM && parh.v == oldh.v) { parh = newh; } int c = Children(); if(c >= 1) a->Substitute(oldh, newh); if(c >= 2) b->Substitute(oldh, newh); } //----------------------------------------------------------------------------- // If the expression references only one parameter that appears in pl, then // return that parameter. If no param is referenced, then return NO_PARAMS. // If multiple params are referenced, then return MULTIPLE_PARAMS. //----------------------------------------------------------------------------- const hParam Expr::NO_PARAMS = { 0 }; const hParam Expr::MULTIPLE_PARAMS = { 1 }; hParam Expr::ReferencedParams(ParamList *pl) { if(op == PARAM) { if(pl->FindByIdNoOops(parh)) { return parh; } else { return NO_PARAMS; } } if(op == PARAM_PTR) oops(); int c = Children(); if(c == 0) { return NO_PARAMS; } else if(c == 1) { return a->ReferencedParams(pl); } else if(c == 2) { hParam pa, pb; pa = a->ReferencedParams(pl); pb = b->ReferencedParams(pl); if(pa.v == NO_PARAMS.v) { return pb; } else if(pb.v == NO_PARAMS.v) { return pa; } else if(pa.v == pb.v) { return pa; // either, doesn't matter } else { return MULTIPLE_PARAMS; } } else oops(); } //----------------------------------------------------------------------------- // Routines to pretty-print an expression. Mostly for debugging. //----------------------------------------------------------------------------- std::string Expr::Print(void) { char c; switch(op) { case PARAM: return ssprintf("p(%x,%g)", parh.v,SK.GetParam(parh)->val); case PARAM_PTR: return ssprintf("p(p%x,%g)", parp->h.v,SK.GetParam(parp->h)->val); case CONSTANT: return ssprintf("%.3f", v); case PLUS: c = '+'; goto p; case MINUS: c = '-'; goto p; case TIMES: c = '*'; goto p; case DIV: c = '/'; goto p; p: return "(" + a->Print() + " " + c + " " + b->Print() + ")"; break; case NEGATE: return "(- " + a->Print() + ")"; case SQRT: return "(sqrt " + a->Print() + ")"; case SQUARE: return "(square " + a->Print() + ")"; case SIN: return "(sin " + a->Print() + ")"; case COS: return "(cos " + a->Print() + ")"; case ASIN: return "(asin " + a->Print() + ")"; case ACOS: return "(acos " + a->Print() + ")"; default: oops(); } } //----------------------------------------------------------------------------- // A parser; convert a string to an expression. Infix notation, with the // usual shift/reduce approach. I had great hopes for user-entered eq // constraints, but those don't seem very useful, so right now this is just // to provide calculator type functionality wherever numbers are entered. //----------------------------------------------------------------------------- #define MAX_UNPARSED 1024 static Expr *Unparsed[MAX_UNPARSED]; static int UnparsedCnt, UnparsedP; static Expr *Operands[MAX_UNPARSED]; static int OperandsP; static Expr *Operators[MAX_UNPARSED]; static int OperatorsP; void Expr::PushOperator(Expr *e) { if(OperatorsP >= MAX_UNPARSED) throw "operator stack full!"; Operators[OperatorsP++] = e; } Expr *Expr::TopOperator(void) { if(OperatorsP <= 0) throw "operator stack empty (get top)"; return Operators[OperatorsP-1]; } Expr *Expr::PopOperator(void) { if(OperatorsP <= 0) throw "operator stack empty (pop)"; return Operators[--OperatorsP]; } void Expr::PushOperand(Expr *e) { if(OperandsP >= MAX_UNPARSED) throw "operand stack full"; Operands[OperandsP++] = e; } Expr *Expr::PopOperand(void) { if(OperandsP <= 0) throw "operand stack empty"; return Operands[--OperandsP]; } Expr *Expr::Next(void) { if(UnparsedP >= UnparsedCnt) return NULL; return Unparsed[UnparsedP]; } void Expr::Consume(void) { if(UnparsedP >= UnparsedCnt) throw "no token to consume"; UnparsedP++; } int Expr::Precedence(Expr *e) { if(e->op == ALL_RESOLVED) return -1; // never want to reduce this marker if(e->op != BINARY_OP && e->op != UNARY_OP) oops(); switch(e->c) { case 'q': case 's': case 'c': case 'n': return 30; case '*': case '/': return 20; case '+': case '-': return 10; default: oops(); } } void Expr::Reduce(void) { Expr *a, *b; Expr *op = PopOperator(); Expr *n; int o; switch(op->c) { case '+': o = PLUS; goto c; case '-': o = MINUS; goto c; case '*': o = TIMES; goto c; case '/': o = DIV; goto c; c: b = PopOperand(); a = PopOperand(); n = a->AnyOp(o, b); break; case 'n': n = PopOperand()->Negate(); break; case 'q': n = PopOperand()->Sqrt(); break; case 's': n = (PopOperand()->Times(Expr::From(PI/180)))->Sin(); break; case 'c': n = (PopOperand()->Times(Expr::From(PI/180)))->Cos(); break; default: oops(); } PushOperand(n); } void Expr::ReduceAndPush(Expr *n) { while(Precedence(n) <= Precedence(TopOperator())) { Reduce(); } PushOperator(n); } void Expr::Parse(void) { Expr *e = AllocExpr(); e->op = ALL_RESOLVED; PushOperator(e); for(;;) { Expr *n = Next(); if(!n) throw "end of expression unexpected"; if(n->op == CONSTANT) { PushOperand(n); Consume(); } else if(n->op == PAREN && n->c == '(') { Consume(); Parse(); n = Next(); if(n->op != PAREN || n->c != ')') throw "expected: )"; Consume(); } else if(n->op == UNARY_OP) { PushOperator(n); Consume(); continue; } else if(n->op == BINARY_OP && n->c == '-') { // The minus sign is special, because it might be binary or // unary, depending on context. n->op = UNARY_OP; n->c = 'n'; PushOperator(n); Consume(); continue; } else { throw "expected expression"; } n = Next(); if(n && n->op == BINARY_OP) { ReduceAndPush(n); Consume(); } else { break; } } while(TopOperator()->op != ALL_RESOLVED) { Reduce(); } PopOperator(); // discard the ALL_RESOLVED marker } void Expr::Lex(const char *in) { while(*in) { if(UnparsedCnt >= MAX_UNPARSED) throw "too long"; char c = *in; if(isdigit(c) || c == '.') { // A number literal char number[70]; int len = 0; while((isdigit(*in) || *in == '.') && len < 30) { number[len++] = *in; in++; } number[len++] = '\0'; Expr *e = AllocExpr(); e->op = CONSTANT; e->v = atof(number); Unparsed[UnparsedCnt++] = e; } else if(isalpha(c) || c == '_') { char name[70]; int len = 0; while(isforname(*in) && len < 30) { name[len++] = *in; in++; } name[len++] = '\0'; Expr *e = AllocExpr(); if(strcmp(name, "sqrt")==0) { e->op = UNARY_OP; e->c = 'q'; } else if(strcmp(name, "cos")==0) { e->op = UNARY_OP; e->c = 'c'; } else if(strcmp(name, "sin")==0) { e->op = UNARY_OP; e->c = 's'; } else if(strcmp(name, "pi")==0) { e->op = CONSTANT; e->v = PI; } else { throw "unknown name"; } Unparsed[UnparsedCnt++] = e; } else if(strchr("+-*/()", c)) { Expr *e = AllocExpr(); e->op = (c == '(' || c == ')') ? PAREN : BINARY_OP; e->c = c; Unparsed[UnparsedCnt++] = e; in++; } else if(isspace(c)) { // Ignore whitespace in++; } else { // This is a lex error. throw "unexpected characters"; } } } Expr *Expr::From(const char *in, bool popUpError) { UnparsedCnt = 0; UnparsedP = 0; OperandsP = 0; OperatorsP = 0; Expr *r; try { Lex(in); Parse(); r = PopOperand(); } catch (const char *e) { dbp("exception: parse/lex error: %s", e); if(popUpError) { #ifndef LIBRARY Error("Not a valid number or expression: '%s'", in); #endif } return NULL; } return r; } |
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