( CONSTANTS AND VARIABLES ------------------------------------------------------ )
: CONSTANT
- WORD ( get the name (the name follows CONSTANT) )
- CREATE ( make the dictionary entry )
+ WORD HEADER ( make dictionary entry (the name follows CONSTANT) )
DOCOL , ( append DOCOL (the codeword field of this word) )
['] LIT , ( append the codeword LIT )
, ( append the value on the top of the stack )
: VARIABLE
1 CELLS ALLOT ( allocate 1 cell of memory, push the pointer to this memory )
- WORD CREATE ( make the dictionary entry (the name follows VARIABLE) )
+ WORD HEADER ( make the dictionary entry (the name follows VARIABLE) )
DOCOL , ( append DOCOL (the codeword field of this word) )
['] LIT , ( append the codeword LIT )
, ( append the pointer to the new memory )
: VALUE ( n -- )
- WORD CREATE ( make the dictionary entry (the name follows VALUE) )
+ WORD HEADER ( make the dictionary entry (the name follows VALUE) )
DOCOL , ( append DOCOL )
['] LIT , ( append the codeword LIT )
, ( append the initial value )
DROP ( at this point, the stack is: start-of-word end-of-word )
SWAP ( end-of-word start-of-word )
+ DUP >CFA @ CASE
+ DOCOL OF
+ \ Colon definition
+ ':' EMIT SPACE DUP ID. SPACE
+ DUP ?IMMEDIATE IF ." IMMEDIATE " THEN CR
+ ENDOF
+ DOVAR OF
+ \ Variable definition
+ ." Variable " DUP ID. CR
+ 2DROP EXIT
+ ENDOF
+ DOCON OF
+ \ Constant definition
+ ." Constant " DUP ID. CR
+ 2DROP EXIT
+ ENDOF
+
+ \ Unknown codeword
+ ." Primitive or word with unrecognized codeword." CR
+ DROP 2DROP EXIT
+ ENDCASE
+
( begin the definition with : NAME [IMMEDIATE] )
- ':' EMIT SPACE DUP ID. SPACE
- DUP ?IMMEDIATE IF ." IMMEDIATE " THEN CR 4
+ ( ':' EMIT SPACE DUP ID. SPACE
+ DUP ?IMMEDIATE IF ." IMMEDIATE " THEN CR 4 )
+
+ 4 SPACES
>DFA ( get the data address, ie. points after DOCOL | end-of-word start-of-data )
2DROP ( restore stack )
;
-
-( WELCOME MESSAGE ------------------------------------------------------------- )
-
-CR CR ." --- TimForth initialized --- "
-
-