The initial iterative replacement solution I came up with (below) quickly
runs out of resources as it has to build the entire list before starting to
draw.
What error did you get?
How much resources does picolisp use?
Do you call ulimit before?
I think you may have some fundamental problems with garabarage allocation.
Please see if you understand that code.
(de expensive-list-increaser (A N)
(default N 1)
(prinl "call: " N)
(if A
(cons
(+ 1 (car A))
(expensive-list-increaser
(copy (prinl (cdr A)))
(inc N))))
(prinl "A of " N " is no no longer refernced after the function number "
N " returns")
@@)
(de compreku (D) (expensive-list-increaser (range 1 D))
Picolisp can not garbage collect A of the first call until all other are
finished since the first A could be needed inside first call at a later
point. This is related to PicoLisp not having tail recursion.
You also need to understand that 'mapcar and 'map returns a new list not
the old one modified. This means you create a copy of the list with each
mapcar the longest of which is only cleared after the first recursive call
is finished.
(de compiter (D) (for ( N . A) (range 1 D)
(prinl "call: " N)
(prinl (copy A))
(prinl "The copy of A is no longer accessible so it can be deallocated")))
# : (compreku 5)
call: 1
2345
call: 2
345
call: 3
45
call: 4
5
call: 5
call: 6
A of 6 is no no longer refernced after the function number 6 returns
A of 5 is no no longer refernced after the function number 5 returns
A of 4 is no no longer refernced after the function number 4 returns
A of 3 is no no longer refernced after the function number 3 returns
A of 2 is no no longer refernced after the function number 2 returns Y
A of 1 is no no longer refernced after the function number 1 returns
#: (compiter 5)
call: 1
1
The copy of A is no longer accessible so it can be deallocated
call: 2
2
The copy of A is no longer accessible so it can be deallocated
call: 3
3
The copy of A is no longer accessible so it can be deallocated
call: 4
4
The copy of A is no longer accessible so it can be deallocated
call: 5
5
The copy of A is no longer accessible so it can be deallocated
2017-03-03 12:47 GMT+01:00 Joh-Tob Schäg <johtob...@gmail.com>:
> Is the garbage collection in picolisp immediate if the resource can be
> released?
>
> No, picolisp uses a mark and sweep halt the world garage collector. During
> sweep phase the complete allocated RAM is checked. If that would happen
> after each release of a resource picolisp would be very slow.
> Furthermore in Picolisp it is not possible to decide whether a resource
> can be released or not with out doing mark and sweep. This is because of
> cyclic list and the fact that you could always have a symbol pointing to
> that cell.
>
>
>
> 2017-03-03 12:04 GMT+01:00 Lindsay John Lawrence <
> lawrence.lindsayj...@gmail.com>:
>
>>
>> Is the garbage collection in picolisp immediate if the resource can be
>> released?
>>
>> The initial iterative replacement solution I came up with (below) quickly
>> runs out of resources as it has to build the entire list before starting to
>> draw.
>>
>> I haven't figured out how to do it yet, but I think, in this case, a
>> 'recursive' solution that renders as points are created would use a lot
>> less resources, assuming that processed replacement rules are garbage
>> collected as the stack unwinds and elements are traversed over.
>>
>> It would be a nice accomplishment to be able to render the more complex
>> fractal plants expressed here: https://en.wikipedia.org/wiki/L-system
>>
>> /Lindsay
>>
>>
>> # https://en.wikipedia.org/wiki/Gosper_curve
>> # Angle 60 degrees = PI/3
>> # Axiom A
>> # Replacement Rules
>> # A :--> A - B - - B + A + + A A + B -
>> # B :--> + A - B B - - B - A + + A + B
>>
>> # C (initially = A) grows...very quickly.
>> #: n=0 (length C) -> 15
>> #: n=1 (length (setq C (F C))) -> 113
>> #: n=2 -> 799, n=3 -> 5601, n=4 -> 39215, n=5 -> 274513, n=6 -> 1921599,
>> n=7 .
>>
>> # For n=6...
>> : (bench (nil (Draw-Gosper-Curve)))
>> -> 1.370 sec
>>
>> Which works out to:
>>
>> XY Cnt: 823543 coordinates to plot
>> Min-XY: -66,432.00 -42,345.11
>> Max-XY: 2,048.00 23,611.35"
>>
>> ...about 900K of serialized canvas instructions.
>>
>>
>> Full-code at: https://github.com/thinknlive/picolisp-gosper
>>
>> (de Gosper-Curve (Length Angle N)
>> (let
>> (A (chop "A-B--B+A++AA+B-")
>> B (chop "+A-BB--B-A++A+B")
>> C A
>> F '((L) (fish atom
>> (mapcar '((X)
>> (cond
>> ((= X "A") A)
>> ((= X "B") B)
>> (T X))) L))) )
>>
>>
>> # Generate points
>> (do N (setq C (F C)))
>>
>> # Plot points
>> (map '((R)
>> (case (car R)
>> (("A" "B") (Plot-Line Length Angle))
>> ("+" (setq Angle (+ Angle PI/3)))
>> ("-" (setq Angle (- Angle PI/3)))
>> (T (msg (text "?Gosper-Curve: No-match: @1" @))) )) C )
>>
>> ) )
>>
>>
>>
>
