| 472 | |
| 473 | #ifdef TE_POW_FROM_RIGHT |
| 474 | static te_expr *factor(state *s) { |
| 475 | /* <factor> = <power> {"^" <power>} */ |
| 476 | te_expr *ret = power(s); |
| 477 | CHECK_NULL(ret); |
| 478 | |
| 479 | int neg = 0; |
| 480 | |
| 481 | if (ret->type == (TE_FUNCTION1 | TE_FLAG_PURE) && ret->function == negate) { |
| 482 | te_expr *se = ret->parameters[0]; |
| 483 | free(ret); |
| 484 | ret = se; |
| 485 | neg = 1; |
| 486 | } |
| 487 | |
| 488 | te_expr *insertion = 0; |
| 489 | |
| 490 | while (s->type == TOK_INFIX && (s->function == pow)) { |
| 491 | te_fun2 t = s->function; |
| 492 | next_token(s); |
| 493 | |
| 494 | if (insertion) { |
| 495 | /* Make exponentiation go right-to-left. */ |
| 496 | te_expr *p = power(s); |
| 497 | CHECK_NULL(p, te_free(ret)); |
| 498 | |
| 499 | te_expr *insert = NEW_EXPR(TE_FUNCTION2 | TE_FLAG_PURE, insertion->parameters[1], p); |
| 500 | CHECK_NULL(insert, te_free(p), te_free(ret)); |
| 501 | |
| 502 | insert->function = t; |
| 503 | insertion->parameters[1] = insert; |
| 504 | insertion = insert; |
| 505 | } else { |
| 506 | te_expr *p = power(s); |
| 507 | CHECK_NULL(p, te_free(ret)); |
| 508 | |
| 509 | te_expr *prev = ret; |
| 510 | ret = NEW_EXPR(TE_FUNCTION2 | TE_FLAG_PURE, ret, p); |
| 511 | CHECK_NULL(ret, te_free(p), te_free(prev)); |
| 512 | |
| 513 | ret->function = t; |
| 514 | insertion = ret; |
| 515 | } |
| 516 | } |
| 517 | |
| 518 | if (neg) { |
| 519 | te_expr *prev = ret; |
| 520 | ret = NEW_EXPR(TE_FUNCTION1 | TE_FLAG_PURE, ret); |
| 521 | CHECK_NULL(ret, te_free(prev)); |
| 522 | |
| 523 | ret->function = negate; |
| 524 | } |
| 525 | |
| 526 | return ret; |
| 527 | } |
| 528 | #else |
| 529 | static te_expr *factor(state *s) { |
| 530 | /* <factor> = <power> {"^" <power>} */ |