Routines
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44375: Match A Class 176 Word
Used by the routines at CopyDisplayIfNeeded and HandleClassAWord.
Grammar handler for word class 176. It matches the word in D against the earlier clause records, which are kept in a linked list.
MatchWordAgainstEarlierClause 44375 LD A,(40986) Read the parser count, count down one and point HL at 40978.
44378 DEC A
44379 LD HL,40978
44382 DEC A Jump ahead to MatchWordAgainstEarlierClause_AdvanceCount unless the parser count was 2.
44383 LD A,D
44384 JR NZ,MatchWordAgainstEarlierClause_AdvanceCount
44386 CP 160 Jump to MatchWordAgainstEarlierClause_0 when the token is 160.
44388 JR Z,MatchWordAgainstEarlierClause_0
MatchWordAgainstEarlierClause_AdvanceCount 44390 INC (HL) Count one more at 40978.
MatchWordAgainstEarlierClause_0 44391 CP 160 Jump back to 43709 if the token is 160.
44393 JP Z,43709
44396 LD A,(40987) Jump to MatchWordAgainstEarlierClause_CountClauses if the initialised flag is zero.
44399 AND A
44400 JR Z,MatchWordAgainstEarlierClause_CountClauses
44402 LD IY,(40944) Point IY at the clause list at 40944.
44406 CALL FollowCharacterLink Call FollowCharacterLink to follow the clause link.
44409 LD A,(IY+1) Read the clause marker.
44412 AND 127 Go to MatchWordAgainstEarlierClause_LaterList if this clause word is not zero.
44414 OR (IY+0)
44417 JR NZ,MatchWordAgainstEarlierClause_LaterList
44419 LD A,(40987) Read the initialised flag into DE.
44422 LD E,A
44423 LD D,0
44425 LD HL,(40944) Point HL at the clause list at 40944.
44428 LD A,(IY+1) Keep bit 7 of the clause marker and merge it into the second byte of the record at the pointer in 40944.
44431 AND 128
44433 INC HL
44434 OR (HL)
44435 LD (HL),A
44436 DEC HL Step HL back, add the offset, and move IY on eight bytes.
44437 ADD HL,DE
44438 LD DE,8
44441 ADD IY,DE
44443 PUSH IY Call CopyDisplayDataIfZero to copy this pair when it is still clear.
44445 POP DE
44446 CALL CopyDisplayDataIfZero
44449 CALL CopyDisplayDataIfZero Call CopyDisplayDataIfZero again and go to MatchWordAgainstEarlierClause_1 when the source low byte is zero.
44452 JR Z,MatchWordAgainstEarlierClause_1
44454 PUSH DE Call CopyDisplayDataIfZero to copy the pair two bytes back.
44455 PUSH HL
44456 DEC DE
44457 DEC DE
44458 CALL CopyDisplayDataIfZero
44461 POP HL
44462 POP DE Restore the saved source from the stack.
MatchWordAgainstEarlierClause_1 44463 CALL CopyDisplayDataIfZero Call CopyDisplayDataIfZero.
44466 LD IY,(40944) Point IY at the clause list at 40944 and jump to MatchWordAgainstEarlierClause_Next.
44470 JR MatchWordAgainstEarlierClause_Next
Starts this walk at the saved clause list.
MatchWordAgainstEarlierClause_LaterList 44472 LD IY,40946 Point IY at 40944+2.
MatchWordAgainstEarlierClause_Next 44476 LD L,(IY-2) Read this clause record's link.
44479 LD H,(IY-1)
44482 PUSH HL Copy the clause link from HL into IX.
44483 POP IX
44485 LD L,(IX-2) Read the link of the previous record.
44488 LD H,(IX-1)
44491 LD (IY-2),L Store the low byte of that link.
44494 LD (IY-1),H Store the high byte and call ProcessMemoryEntry.
44497 CALL ProcessMemoryEntry
MatchWordAgainstEarlierClause_CountClauses 44500 LD IY,40946 Point IY at 40944+2 and take the count at 40978.
44504 LD A,(40978)
44507 LD B,A
44508 PUSH BC Call StepToNextClauseRecord to step to the next clause record.
44509 CALL StepToNextClauseRecord
MatchWordAgainstEarlierClause_Loop 44512 LD A,B Jump ahead to MatchWordAgainstEarlierClause_MatchClause if the count is zero.
44513 AND A
44514 JR Z,MatchWordAgainstEarlierClause_MatchClause
Steps to the next clause record.
44516 CALL StepToNextClauseRecord Call StepToNextClauseRecord to step to the next clause record.
44519 LD A,(40996) Jump to MatchWordAgainstEarlierClause_ClauseMarker if the command mode at 40996 is not 2.
44522 CP 2
44524 JR NZ,MatchWordAgainstEarlierClause_ClauseMarker
44526 PUSH IY Point HL at byte 24 of the record (IY+24) and save it.
44528 POP HL
44529 LD DE,24
44532 ADD HL,DE
44533 PUSH HL
44534 LD D,6 Take a length of 6 and clear the merge.
44536 XOR A
MatchWordAgainstEarlierClause_TestCountFinished 44537 OR (HL) Jump back to MatchWordAgainstEarlierClause_TestCountFinished while the count is not finished.
44538 INC HL
44539 DEC D
44540 JR NZ,MatchWordAgainstEarlierClause_TestCountFinished
44542 POP HL Restore the saved pointer from the stack.
44543 AND A Go to MatchWordAgainstEarlierClause_ClauseMarker when any of the six bytes just merged is set.
44544 JR NZ,MatchWordAgainstEarlierClause_ClauseMarker
44546 EX DE,HL Swap the pointers and point HL at IX, with 0024 ready to add.
44547 PUSH IX
44549 POP HL
44550 PUSH BC
44551 LD BC,24
44554 ADD HL,BC Point HL at byte 24 of the record (IX+24) and copy 6 bytes.
44555 LD BC,6
44558 LDIR
44560 POP BC
MatchWordAgainstEarlierClause_ClauseMarker 44561 LD A,(IY+1) Read the byte at IY+1.
44564 AND 127 Call MergeCharacterFlags if the link word is zero.
44566 OR (IY+0)
44569 CALL Z,MergeCharacterFlags
44572 JR MatchWordAgainstEarlierClause_Loop Jump back to MatchWordAgainstEarlierClause_Loop for the next clause record.
Matches the word against the saved clause list, and returns zero when none match.
MatchWordAgainstEarlierClause_MatchClause 44574 POP BC Call InitialiseCharacterSearch to initialise character search.
44575 CALL InitialiseCharacterSearch
44578 CALL StepThroughSavedClauseList Call StepThroughSavedClauseList to step through the saved clause list.
MatchWordAgainstEarlierClause_2 44581 LD A,B Jump ahead to MatchWordAgainstEarlierClause_SignalStepFailed if the count is zero.
44582 AND A
44583 JP Z,MatchWordAgainstEarlierClause_SignalStepFailed
Steps to the next saved clause record.
44586 CALL StepThroughSavedClauseList Call StepThroughSavedClauseList to step through the saved clause list.
44589 LD A,(IY+18) Go back to MatchWordAgainstEarlierClause_2 if the next link is set.
44592 OR (IY+19)
44595 JR NZ,MatchWordAgainstEarlierClause_2
44597 LD A,(IY+0) Jump back to MatchWordAgainstEarlierClause_2 while this id does not match the record's flag byte.
44600 CP (IX+0)
44603 JR NZ,MatchWordAgainstEarlierClause_2
44605 LD A,(IY+1) Jump back to MatchWordAgainstEarlierClause_2 while this id does not match the moved marker.
44608 CP (IX+1)
44611 JR NZ,MatchWordAgainstEarlierClause_2
44613 LD A,(IX+14) Go back to MatchWordAgainstEarlierClause_2 if the attribute word is zero.
44616 OR (IX+15)
44619 JR Z,MatchWordAgainstEarlierClause_2
44621 EXX Call 44839 to read the schedule field.
44622 LD DE,14
44625 CALL 44839
44628 JP MatchWordAgainstEarlierClause_2 Jump back to MatchWordAgainstEarlierClause_2 for the next clause record.
MatchWordAgainstEarlierClause_SignalStepFailed 44631 XOR A Clear A.
44632 RET Return.
View the equivalent code in;
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