comparison: parser.cxx
parser.cxx
- changeset 46
- a29eeecf3ecb
- parent 45
- e1d3b7ea975c
- child 47
- d84d82213137
equal
deleted
inserted
replaced
| 45:e1d3b7ea975c | 46:a29eeecf3ecb |
|---|---|
| 531 // ============================================================================ | 531 // ============================================================================ |
| 532 // Parses an expression, potentially recursively | 532 // Parses an expression, potentially recursively |
| 533 DataBuffer* ScriptReader::ParseExpression (int reqtype) { | 533 DataBuffer* ScriptReader::ParseExpression (int reqtype) { |
| 534 DataBuffer* retbuf = new DataBuffer (64); | 534 DataBuffer* retbuf = new DataBuffer (64); |
| 535 | 535 |
| 536 DataBuffer* lb = NULL; | 536 // Parse first operand |
| 537 | 537 retbuf->Merge (ParseExprValue (reqtype)); |
| 538 lb = ParseExprValue (reqtype); | 538 |
| 539 | 539 // Parse any and all operators we get |
| 540 // Get an operator | 540 int oper; |
| 541 int oper = ParseOperator (true); | 541 while ((oper = ParseOperator (true)) != -1) { |
| 542 | 542 // We peeked the operator, move forward now |
| 543 // No operator found - stop here. | 543 MustNext(); |
| 544 if (oper == -1) { | 544 |
| 545 retbuf->Merge (lb); | 545 // Can't be an assignement operator, those belong in assignments. |
| 546 return retbuf; | 546 if (IsAssignmentOperator (oper)) |
| 547 } | 547 ParserError ("assignment operator inside expressions"); |
| 548 | 548 |
| 549 // We peeked the operator, move forward now | 549 // Parse the right operand, |
| 550 MustNext(); | 550 MustNext (); |
| 551 | 551 DataBuffer* rb = ParseExprValue (reqtype); |
| 552 // Can't be an assignement operator, those belong in assignments. | 552 |
| 553 if (IsAssignmentOperator (oper)) | 553 // Write to buffer |
| 554 ParserError ("assignment operator inside expressions"); | 554 retbuf->Merge (rb); |
| 555 | 555 long dh = DataHeaderByOperator (NULL, oper); |
| 556 // Parse the right operand, | 556 retbuf->Write<word> (dh); |
| 557 MustNext (); | 557 } |
| 558 DataBuffer* rb = ParseExprValue (reqtype); | 558 |
| 559 | |
| 560 retbuf->Merge (lb); | |
| 561 retbuf->Merge (rb); | |
| 562 | |
| 563 long dh = DataHeaderByOperator (NULL, oper); | |
| 564 retbuf->Write<word> (dh); | |
| 565 return retbuf; | 559 return retbuf; |
| 566 } | 560 } |
| 567 | 561 |
| 568 // ============================================================================ | 562 // ============================================================================ |
| 569 // `arses an operator string. Returns the operator number code. | 563 // Parses an operator string. Returns the operator number code. |
| 570 int ScriptReader::ParseOperator (bool peek) { | 564 int ScriptReader::ParseOperator (bool peek) { |
| 571 str oper; | 565 str oper; |
| 572 if (peek) | 566 if (peek) |
| 573 oper += PeekNext (); | 567 oper += PeekNext (); |
| 574 else | 568 else |
| 683 if (g_CurMode == MODE_TOPLEVEL) // TODO: lift this restriction | 677 if (g_CurMode == MODE_TOPLEVEL) // TODO: lift this restriction |
| 684 ParserError ("can't alter variables at top level"); | 678 ParserError ("can't alter variables at top level"); |
| 685 | 679 |
| 686 // Parse the right operand, | 680 // Parse the right operand, |
| 687 MustNext (); | 681 MustNext (); |
| 688 DataBuffer* retbuf = ParseExprValue (TYPE_INT); | 682 DataBuffer* retbuf = ParseExpression (TYPE_INT); |
| 689 | 683 |
| 690 long dh = DataHeaderByOperator (var, oper); | 684 long dh = DataHeaderByOperator (var, oper); |
| 691 retbuf->Write<word> (dh); | 685 retbuf->Write<word> (dh); |
| 692 retbuf->Write<word> (var->index); | 686 retbuf->Write<word> (var->index); |
| 693 | 687 |
