Routines
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AF90: Parser: Validate Input Tokens
Output
A The number of references to items in the user input tokens
F The zero flag is set when there is only a verb present
F The zero flag is unset when there is at least one valid direct object
F The carry flag is set when the command is malformed
The first token is the verb, so target the second token for the direct object.
Parser_ValidateInputTokens AF90 LD A,($A825) Fetch the second token from the user input and store it in A.
AF93 CP $FF Return if there is no second token.
AF95 RET Z
There is a second token; so validate all direct objects after this point.
AF96 CALL Parser_CountItems Call Parser_CountItems.
AF99 RET NZ Return if there is at least one valid item mentioned in the user input tokens.
Any references are invalid.
Print "Please rephrase that.".
AF9A CALL Response_PleaseRephraseThat Call Response_PleaseRephraseThat.
AF9D SCF Set the carry flag.
AF9E RET Return.
View the equivalent code in The Jewels Of Babylon.
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