( The following sample code comes from the Forth Tutorial )
( found at www.softsynth.com/pforth/pf_tut.htm and is taken with permission. )
23 7 9182
.
.S
0SP .S \ That's a 'zero' 0, not an 'oh' 0.
777 DUP .S
0SP
23 7 .S
SWAP .S
SWAP .S
OVER .S
OVER .S
0SP 11 22 .S
DROP .S
0SP
11 22 33 44 .S
ROT .S
0SP
14 13 12 11 10
3 PICK . ( prints 13 )
0 PICK . ( prints 10 )
4 PICK .
0SP 5 ?DUP
0SP 0 ?DUP
0SP 1 2 3 4 2SWAP
0SP 11 22 33 44 2OVER
0SP 1 2 3 4 2DROP
0SP 5 6 NIP
0SP 10 20 TUCK
0SP 11 22 33 SWAP DUP
0SP 11 22 33 ROT DROP
0SP 11 22 33 ROT DUP 3 PICK
0SP 11 22 33 SWAP OVER 3 PICK
0SP 11 22 33 -ROT 2DUP
0SP
2 3 + .
2 3 + 10 + .
30 5 - .
30 5 / .
30 5 * .
30 5 + 7 / .
10 1- .
7 2* 1+ .
15 5 / .
27 5 / .
: AVERAGE ( a b -- avg ) + 2/ ;
10 20 AVERAGE .
: TEST ( --) 50 60 AVERAGE . ;
TEST
0SP
53 10 /MOD .S
0SP
7 5 MOD .S
56 34 MAX .
56 34 MIN .
-17 0 MIN .
-17 ABS .
10 NEGATE .
-3 NEGATE .
25 3 LSHIFT .
25 2 RSHIFT .
: 256* 8 LSHIFT ;
3 256* .
3 4 * 20 +
0SP
20 17 - 12 * .
1 4 -18 * 6 / - .
6 13 * 4 2 * 7 * - .
: SQUARE ( N -- N*N )
   DUP *
;
5 SQUARE .
: DIFF.SQUARES ( A B -- A*A-B*B )
SWAP SQUARE
SWAP SQUARE -
;
5 3 DIFF.SQUARES .
: AVERAGE4 ( A B C D -- [A+B+C+D]/4 )
   + + + ( add'em up)
   4/
;
0SP 1 2 4 5 AVERAGE4 .
: HMS>SECONDS ( HOURS MINUTES SECONDS -- TOTAL-SECONDS )
   -ROT SWAP ( -- seconds minutes hours )
   60 * + ( -- seconds total-minutes )
   60 * + ( -- seconds )
;
0SP 2 33 45 HMS>SECONDS .
72 EMIT 105 EMIT
CHAR W .
CHAR % DUP . EMIT
CHAR A DUP .
32 + EMIT
: TOFU ." Yummy bean curd!" ;
TOFU
: SPROUTS ." Miniature vegetables." ;
: MENU
   CR TOFU CR SPROUTS CR
;
MENU
CR TOFU SPROUTS
CR TOFU SPACE SPROUTS
CR 10 SPACES TOFU CR 20 SPACES SPROUTS
INCLUDE ForthTst.uc
TEST.SQUARE
VARIABLE MY-VAR
MY-VAR . ( normal for this to be different each for test)
513 MY-VAR !
MY-VAR @ .
: ? ( address -- , look at variable )
   @ .
;
MY-VAR ?
123 REPORT.SCORE
9845 REPORT.SCORE
534 REPORT.SCORE
20 MY-VAR !
5 MY-VAR +!
MY-VAR @ .
23 71 = .
18 18 = .
23 198 < .
23 198 > .
254 15 > .
: DRINK? ( age -- flag , can this person drink? )
   20 >
;
20 DRINK? .
21 DRINK? .
43 DRINK? .
23 0> .
-23 0> .
23 0= .
TRUE TRUE OR .
TRUE FALSE OR .
FALSE FALSE OR .
TRUE TRUE AND .
TRUE FALSE AND .
TRUE .
TRUE NOT .
56 3 > 56 123 < AND .
23 45 = 23 23 = OR .
: LOWERCASE? ( CHAR -- FLAG , true if lowercase )
   DUP 123 <
   SWAP 96 > AND
;
CHAR A LOWERCASE? .
CHAR a LOWERCASE? .
: .L ( flag -- , print logical value )
   IF ." True value on stack!"
   ELSE ." False value on stack!"
   THEN
;
0 .L
FALSE .L
TRUE .L
23 7 < .L
23 .L
: BIGBUCKS? ( amount -- )
   1000 >
   IF ." That's TOO expensive!"
   THEN
;
531 BIGBUCKS?
1021 BIGBUCKS?
VARIABLE ACCOUNT
: DEDUCT ( n -- , subtract from account )
   ACCOUNT @ ( -- n acc )
   SWAP - DUP ACCOUNT ! ( -- acc' , update variable )
   ." Balance = $" DUP . CR ( -- acc' )
   0< ( are we broke? )
   IF ." Warning!! Your account is overdrawn!" CR
   THEN
;
300 ACCOUNT !
40 DEDUCT
200 DEDUCT
100 DEDUCT
: COUNTDOWN ( N -- )
   BEGIN
      DUP . CR     ( print number on top of stack )
      1-  DUP  0<  ( loop until we go negative )
   UNTIL
;
16 COUNTDOWN
0SP
: SPELL
   ." ba"
   4 0 DO
      ." na"
   LOOP
;
SPELL
: .ASCII ( end start -- , dump characters )
   DO
      CR I . I EMIT
   LOOP CR
;
80 64 .ASCII
: SUM.OF.N.1 ( N -- SUM[N] )
   0 SWAP
   1+ 0
   DO
      I +
   LOOP
;
4 SUM.OF.N.1 .
5 SUM.OF.N.1 .
: SUM.OF.N.2
   0
   BEGIN ( -- N' SUM )
      OVER +
      SWAP 1- SWAP
      OVER 0<
   UNTIL
   SWAP DROP
;
4 SUM.OF.N.2 .
5 SUM.OF.N.2 .
: SUM.OF.N.3 ( NUM -- SUM[N] , Gauss' method )
   DUP 1+
   * 2/
;
4 SUM.OF.N.3 .
5 SUM.OF.N.3 .