+: \ IMMEDIATE
+ KEY
+ 10 = 0BRANCH [ -5 , ]
+; \ We can now comment!
+
+\ BASIC DEFINITIONS ----------------------------------------------------------------------
+
: / /MOD SWAP DROP ;
: MOD /MOD DROP ;
: */ -ROT * SWAP / ;
: FALSE 0 ;
: NOT 0= ;
-: CELLS ; \ Allow for slightly more portable code
+\ Translate a number of cells into memory units
+\ (in our case 1 cell = 1 memory unit)
+: CELLS ;
+
+\ Since the smallest unit of memory in our system is 64 bits and since strings
+\ are stored as arrays of 64 bit integers, the character store/fetch words are
+\ just aliases of the standard store/fetch words.
+: C! ! ;
+: C@ @ ;
+: C, , ;
: DEPTH PSP@ PSP0 @ - ;
: '\n' 10 ;
: BL 32 ;
-: LITERAL IMMEDIATE ' LIT , , ;
+: LITERAL IMMEDIATE ['] LIT , , ;
-: ':' [ CHAR : ] LITERAL ;
-: ';' [ CHAR ; ] LITERAL ;
-: '(' [ CHAR ( ] LITERAL ;
-: ')' [ CHAR ) ] LITERAL ;
-: '<' [ CHAR < ] LITERAL ;
-: '>' [ CHAR > ] LITERAL ;
-: '"' [ CHAR " ] LITERAL ;
-: 'A' [ CHAR A ] LITERAL ;
-: '0' [ CHAR 0 ] LITERAL ;
-: '-' [ CHAR - ] LITERAL ;
-: '.' [ CHAR . ] LITERAL ;
+: [CHAR] IMMEDIATE
+ CHAR
+ ['] LIT , ,
+;
: CR '\n' emit ;
: SPACE BL emit ;
\ CONTROL STRUCTURES ----------------------------------------------------------------------
: IF IMMEDIATE
- ' 0BRANCH , \ compile 0BRANCH
+ ['] 0BRANCH , \ compile 0BRANCH
HERE @ \ save location of the offset on the stack
0 , \ compile a dummy offset
;
;
: ELSE IMMEDIATE
- ' BRANCH , \ definite branch to just over the false-part
+ ['] BRANCH , \ definite branch to just over the false-part
HERE @ \ save location of the offset on the stack
0 , \ compile a dummy offset
SWAP \ now back-fill the original (IF) offset
;
: UNTIL IMMEDIATE
- ' 0BRANCH , \ compile 0BRANCH
+ ['] 0BRANCH , \ compile 0BRANCH
HERE @ - \ calculate the offset from the address saved on the stack
, \ compile the offset here
;
: AGAIN IMMEDIATE
- ' BRANCH , \ compile BRANCH
+ ['] BRANCH , \ compile BRANCH
HERE @ - \ calculate the offset back
, \ compile the offset here
;
: WHILE IMMEDIATE
- ' 0BRANCH , \ compile 0BRANCH
+ ['] 0BRANCH , \ compile 0BRANCH
HERE @ \ save location of the offset2 on the stack
0 , \ compile a dummy offset2
;
: REPEAT IMMEDIATE
- ' BRANCH , \ compile BRANCH
+ ['] BRANCH , \ compile BRANCH
SWAP \ get the original offset (from BEGIN)
HERE @ - , \ and compile it after BRANCH
DUP
;
: UNLESS IMMEDIATE
- ' NOT , \ compile NOT (to reverse the test)
+ ['] NOT , \ compile NOT (to reverse the test)
[COMPILE] IF \ continue by calling the normal IF
;
: DO IMMEDIATE
- ' LIT , -1 , [COMPILE] IF
- ' >R , ' >R ,
- ' LIT , HERE @ 0 , ' >R ,
+ ['] LIT , -1 , [COMPILE] IF
+ ['] >R , ['] >R ,
+ ['] LIT , HERE @ 0 , ['] >R ,
HERE @
;
: ?DO IMMEDIATE
- ' 2DUP , ' - , [COMPILE] IF
- ' >R , ' >R ,
- ' LIT , HERE @ 0 , ' >R ,
+ ['] 2DUP , ['] - , [COMPILE] IF
+ ['] >R , ['] >R ,
+ ['] LIT , HERE @ 0 , ['] >R ,
HERE @
;
: J RSP@ 6 - @ ;
: ?LEAVE IMMEDIATE
- ' 0BRANCH , 13 ,
- ' R> , ' RDROP , ' RDROP ,
- ' LIT , HERE @ 7 + , ' DUP , ' -ROT , ' - , ' SWAP , ' ! ,
- ' BRANCH ,
+ ['] 0BRANCH , 13 ,
+ ['] R> , ['] RDROP , ['] RDROP ,
+ ['] LIT , HERE @ 7 + , ['] DUP , ['] -ROT , ['] - , ['] SWAP , ['] ! ,
+ ['] BRANCH ,
0 ,
;
: LEAVE IMMEDIATE
- ' LIT , -1 ,
+ ['] LIT , -1 ,
[COMPILE] ?LEAVE
;
: +LOOP IMMEDIATE
- ' DUP , \ Store copy of increment
+ ['] DUP , \ Store copy of increment
- ' R> , ' SWAP , ' R> , ' SWAP , ' R> , ' SWAP , ' + , ' 2DUP , ' - ,
- ' SWAP , ' >R , ' SWAP , ' >R , ' SWAP , ' >R ,
+ ['] R> , ['] SWAP , ['] R> , ['] SWAP , ['] R> , ['] SWAP , ['] + , ['] 2DUP , ['] - ,
+ ['] SWAP , ['] >R , ['] SWAP , ['] >R , ['] SWAP , ['] >R ,
\ Condition differently depending on sign of increment
- ' SWAP , ' 0>= , [COMPILE] IF
- ' 0<= ,
+ ['] SWAP , ['] 0>= , [COMPILE] IF
+ ['] 0<= ,
[COMPILE] ELSE
- ' 0> ,
+ ['] 0> ,
[COMPILE] THEN
\ Branch back to begining of loop kernel
- ' 0BRANCH , HERE @ - ,
+ ['] 0BRANCH , HERE @ - ,
\ Clean up
- ' RDROP , ' RDROP , ' RDROP ,
+ ['] RDROP , ['] RDROP , ['] RDROP ,
\ Record address of loop end for any LEAVEs to use
HERE @ SWAP !
[COMPILE] ELSE
- ' 2DROP , \ Clean up if loop was entirely skipped (?DO)
+ ['] 2DROP , \ Clean up if loop was entirely skipped (?DO)
[COMPILE] THEN
;
: LOOP IMMEDIATE
- ' LIT , 1 ,
+ ['] LIT , 1 ,
[COMPILE] +LOOP
;
+
+\ CASE ------------------------------------------------------------------------
+
+: CASE IMMEDIATE
+ 0 \ push 0 to mark the bottom of the stack
+;
+
+: OF IMMEDIATE
+ ['] OVER , \ compile OVER
+ ['] = , \ compile =
+ [COMPILE] IF \ compile IF
+ ['] DROP , \ compile DROP
+;
+
+: ENDOF IMMEDIATE
+ [COMPILE] ELSE \ ENDOF is the same as ELSE
+;
+
+: ENDCASE IMMEDIATE
+ ['] DROP , \ compile DROP
+
+ \ keep compiling THEN until we get to our zero marker
+ BEGIN
+ ?DUP
+ WHILE
+ [COMPILE] THEN
+ REPEAT
+;
+
+
\ COMMENTS ----------------------------------------------------------------------
: ( IMMEDIATE
1 \ allowed nested parens by keeping track of depth
BEGIN
KEY \ read next character
- DUP '(' = IF \ open paren?
+ DUP [CHAR] ( = IF \ open paren?
DROP \ drop the open paren
1+ \ depth increases
ELSE
- ')' = IF \ close paren?
+ [CHAR] ) = IF \ close paren?
1- \ depth decreases
THEN
THEN
( print the remainder )
DUP 10 < IF
- '0' ( decimal digits 0..9 )
+ [CHAR] 0 ( decimal digits 0..9 )
ELSE
10 - ( hex and beyond digits A..Z )
- 'A'
+ [CHAR] A
THEN
+
EMIT
SWAP ( u flag )
IF ( was it negative? print the - character )
- '-' EMIT
+ [CHAR] - EMIT
THEN
U.
: . 0 .R SPACE ;
: .S ( -- )
- '<' EMIT DEPTH U. '>' EMIT SPACE
+ [CHAR] < EMIT DEPTH U. [CHAR] > EMIT SPACE
PSP0 @ 1+
BEGIN
DUP PSP@ 2 - <=
( STRINGS ---------------------------------------------------------------------- )
-( Since the smallest unit of memory in our system is 64 bits and since strings
- are stored as arrays of 64 bit integers, the character store/fetch words are
- just aliases of the standard store/fetch words. )
-: C! ! ;
-: C@ @ ;
( Block copy, however, is important and novel: )
: CMOVE ( src dest length -- )
: S" IMMEDIATE ( -- addr len )
STATE @ IF ( compiling? )
- ' LITSTRING , ( compile LITSTRING )
+ ['] LITSTRING , ( compile LITSTRING )
HERE @ ( save the address of the length word on the stack )
0 , ( dummy length - we don't know what it is yet )
KEY DROP
BEGIN
KEY ( get next character of the string )
- DUP '"' <>
+ DUP [CHAR] " <>
WHILE
C, ( copy character )
REPEAT
KEY DROP
BEGIN
KEY
- DUP '"' <>
+ DUP [CHAR] " <>
WHILE
OVER C! ( save next character )
1+ ( increment address )
;
: ." IMMEDIATE ( -- )
- STATE @ IF ( compiling? )
- [COMPILE] S" ( read the string, and compile LITSTRING, etc. )
- ' TELL , ( compile the final TELL )
- ELSE
- ( In immediate mode, just read characters and print them until we get
- to the ending double quote. )
- KEY DROP
- BEGIN
- KEY
- DUP '"' = IF
- DROP ( drop the double quote character )
- EXIT ( return from this function )
- THEN
- EMIT
- AGAIN
- THEN
+ [COMPILE] S" ( read the string, and compile LITSTRING, etc. )
+ ['] TELL , ( compile the final TELL )
;
+: .(
+ KEY DROP
+ BEGIN
+ KEY
+ DUP [CHAR] ) = IF
+ DROP ( drop the double quote character )
+ EXIT ( return from this function )
+ THEN
+ EMIT
+ AGAIN
+;
+
+
( 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 )
- ' EXIT , ( append the codeword EXIT )
+ ['] LIT , ( append the codeword LIT )
+ , ( append the value on the top of the stack )
+ ['] EXIT , ( append the codeword EXIT )
;
-: ALLOT ( n -- addr )
- HERE @ SWAP ( here n )
+: ALLOT ( n -- )
HERE +! ( adds n to HERE, after this the old value of HERE is still on the stack )
;
: VARIABLE
+ CREATE
1 CELLS ALLOT ( allocate 1 cell of memory, push the pointer to this memory )
- WORD CREATE ( 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 )
- ' EXIT , ( append the codeword EXIT )
;
: 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 )
+ ['] LIT , ( append the codeword LIT )
, ( append the initial value )
- ' EXIT , ( append the codeword EXIT )
+ ['] EXIT , ( append the codeword EXIT )
;
: TO IMMEDIATE ( n -- )
>DFA ( get a pointer to the first data field (the 'LIT') )
1+ ( increment to point at the value )
STATE @ IF ( compiling? )
- ' LIT , ( compile LIT )
+ ['] LIT , ( compile LIT )
, ( compile the address of the value )
- ' ! , ( compile ! )
+ ['] ! , ( compile ! )
ELSE ( immediate mode )
! ( update it straightaway )
THEN
>DFA ( get a pointer to the first data field (the 'LIT') )
1+ ( increment to point at the value )
STATE @ IF ( compiling? )
- ' LIT , ( compile LIT )
+ ['] LIT , ( compile LIT )
, ( compile the address of the value )
- ' +! , ( compile +! )
+ ['] +! , ( compile +! )
ELSE ( immediate mode )
+! ( update it straightaway )
THEN
;
+( Fill u ints, starting at a, with the value b )
+: FILL ( a u b -- )
+ -ROT OVER + SWAP ?DO
+ DUP I !
+ LOOP
+ DROP
+;
+
+: ERASE ( a u -- )
+ 0 FILL
+;
( PRINTING THE DICTIONARY ------------------------------------------------------ )
WHILE
SWAP 1+ ( addr len -- len addr+1 )
DUP @ ( len addr -- len addr char | get the next character)
- EMIT ( len addr char -- len addr | and print it)
+ DUP 32 >= OVER 127 <= AND IF
+ EMIT ( len addr char -- len addr | and print it)
+ ELSE
+ BASE @ SWAP HEX
+ ." \x" 0 .R
+ BASE !
+ THEN
SWAP 1- ( len addr -- addr len-1 | subtract one from length )
REPEAT
2DROP ( len addr -- )
CR
;
+
( FORGET ---------------------------------------------------------------------- )
: FORGET
\ TODO!
-( CASE ------------------------------------------------------------------------ )
-
-: CASE IMMEDIATE
- 0 ( push 0 to mark the bottom of the stack )
-;
-
-: OF IMMEDIATE
- ' OVER , ( compile OVER )
- ' = , ( compile = )
- [COMPILE] IF ( compile IF )
- ' DROP , ( compile DROP )
-;
-
-: ENDOF IMMEDIATE
- [COMPILE] ELSE ( ENDOF is the same as ELSE )
-;
-
-: ENDCASE IMMEDIATE
- ' DROP , ( compile DROP )
-
- ( keep compiling THEN until we get to our zero marker )
- BEGIN
- ?DUP
- WHILE
- [COMPILE] THEN
- REPEAT
-;
-
( DECOMPILER ------------------------------------------------------------------ )
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
+ [CHAR] : 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
+ ( [CHAR] : 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 )
DUP @ ( end start codeword )
CASE
- ' LIT OF ( is it LIT ? )
+ ['] LIT OF ( is it LIT ? )
1+ DUP @ ( get next word which is the integer constant )
. ( and print it )
ENDOF
- ' LITSTRING OF ( is it LITSTRING ? )
- [ CHAR S ] LITERAL EMIT '"' EMIT SPACE ( print S"<space> )
+ ['] LITSTRING OF ( is it LITSTRING ? )
+ [CHAR] S EMIT [CHAR] " EMIT SPACE ( print S"<space> )
1+ DUP @ ( get the length word )
SWAP 1+ SWAP ( end start+1 length )
2DUP TELL ( print the string )
- '"' EMIT SPACE ( finish the string with a final quote )
+ [CHAR] " EMIT SPACE ( finish the string with a final quote )
+ ( end start+1+len, aligned )
1- ( because we're about to add 4 below )
ENDOF
- ' 0BRANCH OF ( is it 0BRANCH ? )
+ ['] 0BRANCH OF ( is it 0BRANCH ? )
." 0BRANCH ( "
1+ DUP @ ( print the offset )
.
." ) "
ENDOF
- ' BRANCH OF ( is it BRANCH ? )
+ ['] BRANCH OF ( is it BRANCH ? )
." BRANCH ( "
1+ DUP @ ( print the offset )
.
." ) "
ENDOF
- ' ' OF ( is it ' (TICK) ? )
- [ CHAR ' ] LITERAL EMIT SPACE
+ ['] ['] OF ( is it ['] ? )
+ ." ['] "
1+ DUP @ ( get the next codeword )
CFA> ( and force it to be printed as a dictionary entry )
ID. SPACE
ENDOF
- ' EXIT OF ( is it EXIT? )
+ ['] EXIT OF ( is it EXIT? )
( We expect the last word to be EXIT, and if it is then we don't print it
because EXIT is normally implied by ;. EXIT can also appear in the middle
of words, and then it needs to be printed. )
1+ ( end start+1 )
REPEAT
- ';' EMIT CR
+ [CHAR] ; EMIT CR
2DROP ( restore stack )
;
-( WELCOME MESSAGE ------------------------------------------------------------- )
-
-CR CR ." --- TimForth initialized --- "
-
+( MEMORY ------------------------------------------------------------------ )
+: UNUSED ( -- cells )
+ MEMSIZE HERE @ - ;
The Lambda Lab / projects / forth.jl.git / blobdiff