/* A sometimes minimal FORTH compiler and tutorial for Linux / i386 systems. -*- asm -*-
By Richard W.M. Jones <rich@annexia.org> http://annexia.org/forth
This is PUBLIC DOMAIN (see public domain release statement below).
- $Id: jonesforth.S,v 1.45 2007-10-22 18:53:13 rich Exp $
+ $Id: jonesforth.S,v 1.46 2009-09-11 08:32:32 rich Exp $
gcc -m32 -nostdlib -static -Wl,-Ttext,0 -Wl,--build-id=none -o jonesforth jonesforth.S
*/
pop %eax
pop %ebx
pop %ecx
+ push %ebx
push %eax
push %ecx
- push %ebx
NEXT
defcode "-ROT",4,,NROT
pop %eax
pop %ebx
pop %ecx
- push %ebx
push %eax
push %ecx
+ push %ebx
NEXT
defcode "2DROP",5,,TWODROP // drop top two elements of stack
\ A sometimes minimal FORTH compiler and tutorial for Linux / i386 systems. -*- asm -*-
\ By Richard W.M. Jones <rich@annexia.org> http://annexia.org/forth
\ This is PUBLIC DOMAIN (see public domain release statement below).
-\ $Id: jonesforth.f,v 1.17 2007-10-12 20:07:44 rich Exp $
+\ $Id: jonesforth.f,v 1.18 2009-09-11 08:32:33 rich Exp $
\
\ The first part of this tutorial is in jonesforth.S. Get if from http://annexia.org/forth
\
( Some more complicated stack examples, showing the stack notation. )
: NIP ( x y -- y ) SWAP DROP ;
-: TUCK ( x y -- y x y ) DUP ROT ;
+: TUCK ( x y -- y x y ) SWAP OVER ;
: PICK ( x_u ... x_1 x_0 u -- x_u ... x_1 x_0 x_u )
1+ ( add one because of 'u' on the stack )
4 * ( multiply by the word size )
SWAP ( width u )
DUP ( width u u )
UWIDTH ( width u uwidth )
- -ROT ( u uwidth width )
+ ROT ( u uwidth width )
SWAP - ( u width-uwidth )
( At this point if the requested width is narrower, we'll have a negative number on the stack.
Otherwise the number on the stack is the number of spaces to print. But SPACES won't print
DUP 0< IF
NEGATE ( width u )
1 ( save a flag to remember that it was negative | width n 1 )
- ROT ( 1 width u )
- SWAP ( 1 u width )
+ SWAP ( width 1 u )
+ ROT ( 1 u width )
1- ( 1 u width-1 )
ELSE
0 ( width u 0 )
- ROT ( 0 width u )
- SWAP ( 0 u width )
+ SWAP ( width 0 u )
+ ROT ( 0 u width )
THEN
SWAP ( flag width u )
DUP ( flag width u u )
UWIDTH ( flag width u uwidth )
- -ROT ( flag u uwidth width )
+ ROT ( flag u uwidth width )
SWAP - ( flag u width-uwidth )
SPACES ( flag u )
: ? ( addr -- ) @ . ;
( c a b WITHIN returns true if a <= c and c < b )
+( or define without ifs: OVER - >R - R> U< )
: WITHIN
- ROT ( b c a )
+ -ROT ( b c a )
OVER ( b c a c )
<= IF
> IF ( b c -- )
LATEST @ 128 DUMP
)
: DUMP ( addr len -- )
- BASE @ ROT ( save the current BASE at the bottom of the stack )
+ BASE @ -ROT ( save the current BASE at the bottom of the stack )
HEX ( and switch to hexadecimal mode )
BEGIN
CR
DUP 1- 15 AND 1+ ( addr len linelen )
- DUP ( addr len linelen linelen )
- ROT ( addr linelen len linelen )
+ TUCK ( addr linelen len linelen )
- ( addr linelen len-linelen )
- ROT ( len-linelen addr linelen )
- + ( len-linelen addr+linelen )
- SWAP ( addr-linelen len-linelen )
+ >R + R> ( addr+linelen len-linelen )
REPEAT
DROP ( restore stack )
: R/W ( -- fam ) O_RDWR ;
: OPEN-FILE ( addr u fam -- fd 0 (if successful) | c-addr u fam -- fd errno (if there was an error) )
- ROT ( fam addr u )
+ -ROT ( fam addr u )
CSTRING ( fam cstring )
SYS_OPEN SYSCALL2 ( open (filename, flags) )
DUP ( fd fd )
: CREATE-FILE ( addr u fam -- fd 0 (if successful) | c-addr u fam -- fd errno (if there was an error) )
O_CREAT OR
O_TRUNC OR
- ROT ( fam addr u )
+ -ROT ( fam addr u )
CSTRING ( fam cstring )
- 420 ROT ( 0644 fam cstring )
+ 420 -ROT ( 0644 fam cstring )
SYS_OPEN SYSCALL3 ( open (filename, flags|O_TRUNC|O_CREAT, 0644) )
DUP ( fd fd )
DUP 0< IF ( errno? )
;
: READ-FILE ( addr u fd -- u2 0 (if successful) | addr u fd -- 0 0 (if EOF) | addr u fd -- u2 errno (if error) )
- ROT SWAP -ROT ( u addr fd )
+ >R SWAP R> ( u addr fd )
SYS_READ SYSCALL3
DUP ( u2 u2 )
git.annexia.org / jonesforth.git / commitdiff