feat(buzbee): add tokenizing routines, buzbee feature complete

src/buzbee.s

@@ -40,13 +40,13 @@ BBVAR tagbbvar
   EXPORT BUZBEE
 
 BUZBEE
-  lbsr NEWLINE ; Setup the new input line and handle display.
+  lbsr NEWLINE  ; Setup the new input line and handle display.
-  bsr INPLOOP  ; Fill input buffer.
+  bsr INPLOOP   ; Fill input buffer.
-  cmpy #0      ; No data?
+  cmpy #0       ; No data?
-  beq BUZBEE   ;  Try again...
+  beq BUZBEE    ;  Try again...
-  ; TODO: Parse the input buffer into tokens
+  lbsr TOKENIZE ; Try to tokenize the input buffer
-  lbsr RUNIF
+  lbsr RUNIF    ; Execute token buffer, handling any errors
-  bra BUZBEE
+  bra BUZBEE    ; Repeat
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
@@ -201,6 +201,62 @@ BADHEX@
 ;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
+; Attempts to parse the input buffer into tokens depending on the command
+TOKENIZE
+  ldd BBVAR.cchinput   ; Do we have input to work with?
+  cmpd #4              ; Do we have even enough space for a string command
+  blo TOKFAIL@         ;  No? GTFO
+  ldy #0               ; Initialize Y; used to track current position in BBVAR.input
+  ldx #0               ; Initialize X; used to track position in BBVAR.tokens
+  bsr SKIPTONEXTC      ; Get the next non-whitespace char
+  bsr MKCMDSUM         ; Hash the first four non-whitespace chars
+  bsr HASH2TOKEN       ; Try to turn that hash into a proper token
+  bcs TOKFAIL@
+  bra STTOK@           ; Store token
+NEXTHEX@               ; Next hex token
+  bsr SKIPTONEXTC      ; Skip to next whitespace
+  ldd BBVAR.input,y    ; Get hex value (two digits)
+  bsr HEX2BYT          ; Convert hex value to byte value
+STTOK@
+  sta BBVAR.tokens,x   ; Store curent token
+  leax 1,x             ; Advance to next token
+  cmpx #BBTOKENS_DEPTH ; Is this next token in bounds?
+  beq FULLBUF@         ;  No? handle a full buffer
+  bra NEXTHEX@         ; Try to turn the next character into a hex value
+FULLBUF@
+  PZSTR EM_FULLTOKBUF  ; Print an error message
+  clrd                 ; Say we wrote no tokens
+  std BBVAR.cbtokens
+  rts
+TOKFAIL@
+  PZSTR EM_TOKFAIL     ; Print tokenization fail
+  clrd                 ; Say we wrote no tokens
+  std BBVAR.cbtokens
+  rts
+
+; Converts a runtime command hash into a portable token. Command tokens are
+; indexes into BBCHT, which is generated at compile-time
+; @param A: runtime hash
+; @return A: output token
+; @return CC.C: set if error state, cleared otherwise
+HASH2TOKEN
+  pshs x           ; Preserve & init X; other routines in this group use it
+  ldx #0
+NEXTHASH@
+  cmpa BBCHT,x     ; Is this hash our hash?
+  beq THISHASH@    ;  Yes? turn it into a token
+  leax 1,x         ; Begin considering next hash
+  cmpx BBCHTC      ; Is the next hash even in the table?
+  blo NEXTHASH@    ;  Yes? try this next hash, No? fall through
+  PZSTR EM_BADHASH CALL; Print an error message to the user
+  puls x
+  orcc #1          ; Set CC.C to indicate error
+  rts
+THISHASH@
+  puls x
+  andcc #$FE       ; Clear CC.C to indicate success
+  rts
+
 ; Makes a hash of four chars in BBIN starting at offset X
 ; @param Y: offset in BBIN to read the four chars from
 ; @return A: resulting hash