7th words
To see all words (that are functions and operators) in 7th enter words after the ok> prompt in the command window. For information on a word or a specific topic use help.
7th examples
*** In heavy recursive programms like the Sierpinski triangle in the turtle graphics example below – the JVM will run out of heap- / stack-space. ***
If You have downloaded Seventh.jar separately You need to call the 7th IDE in the following way:java -Xms300m -Xmx300m -jar Seventh.jar
Java runs with increased heap- and stack-space when launched with seventh.bat from Sevjre.zip.
turtle graphics
forget xy
degrees
(0,0i) value xy
5 value ϱ
true value pen?
: fwd ( n -- )
g fn
xy @ >re,im
xy @
6 roll ϱ @
>re,im >complex
+
dup xy !
>re,im
pen? @ if
.drawLine
else
3drop
3drop
then
;
: bkw ( n -- )
negate
fwd
;
: mvfwd ( n -- )
pen? off
fwd
pen? on
;
: mvbkw ( n -- )
pen? off
negate
fwd
pen? on
;
: left ( n -- )
negate ϱ +!
;
: right ( n -- )
ϱ +!
;
: move ( x y -- )
>complex xy !
;
: triangle ( n -- )
3 0 do
dup fwd
120 right
loop
drop
;
: star
350 330 move
pen? on
500 0 do
i isodd? if
i fwd
98 left
then
loop
;
: sierpinski parallel ( length depth -- )
//COLORS depth 30 + @ setcolor
red setcolor
variable length
variable depth
1- depth !
2/ length !
length @ depth @
dup 0 > if
sierpinski
3 0 do
length @ 0.75 * mvfwd
60 right
length @ depth @
sierpinski
loop
else
over 2/ triangle
60 left
over 2/ mvfwd
120 right
drop triangle
then
;
clear
500 100 move
0 ϱ !
now$ type cr
2000 7 sierpinski
now$ type cr
repaint
8 queens puzzle
forget row
8 char-array row
0 array rows
row 8 '_' fill
: block ( -- )
variable r
0 r !
rows for
r @ 1+ r !
8 0 do
forobj i @ 'x' == if
i r @ +
dup 8 < if
dup ':' row rot !
then
drop
i r @ -
dup 0 >= if
dup ':' row rot !
then
drop
'.' row i !
then
loop
each
;
: forward
8 0 do
block
row i @ '_' == if
'x' row i !
leave
then
loop
row
dup println
8 0 do
row i @ ':' == if
'_' row i !
then
loop
rows |<!
rows size 8 < if
forward
then
;
clear
cr
forward