Routines
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AEAF: Parser: Count Item References
Used by the routines at Parser_ValidateDirectObject, AF90 and AFB7.
Count how many tokens in the user input refer to game items.
Output
A The number of references to items in the user input tokens
E As A
F The Z flag is set when there are no items present in the input
Parser_CountItems AEAF LD HL,$A824 Set a pointer to UserInput_Token_1 in HL.
AEB2 LD B,$0A Set a token count in B of 0A which is the total length of the user input tokens.
AEB4 LD E,$00 Initialise the item counter held in E to 00.
Parser_CountItems_Loop AEB6 LD A,(HL) Fetch a user input token.
AEB7 CP $FF Jump to Parser_CountItems_Process if the terminator character (FF) has been reached.
AEB9 JR Z,Parser_CountItems_Process
AEBB PUSH HL Stash the token pointer and token counter on the stack.
AEBC PUSH BC
AEBD LD HL,($A7D8) HL=*Pointer_ObjectList.
AEC0 LD BC,($A7E8) Fetch the count of the number of items in the table from *Count_Objects.
AEC4 CPIR Search to see if the item room ID is in the table.
AEC6 POP BC Restore the token counter and token pointer from the stack.
AEC7 POP HL
AEC8 JR NZ,Parser_CountItems_Skip Jump to Parser_CountItems_Skip if this token doesn't refer to a game item.
This token does point to a game item, so increase the item counter.
AECA INC E Increment item counter by one.
Parser_CountItems_Skip AECB INC HL Move to the next token.
AECC DJNZ Parser_CountItems_Loop Decrease the token counter by one and loop back to Parser_CountItems_Loop until all the tokens have been evaluated.
Parser_CountItems_Process AECE XOR A Transfer the item count into A and set flags accordingly.
AECF OR E
AED0 RET Return.
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