Re: L-system rules with PicoLisp

[Lindsay John Lawrence]

Thanks Alex,
I appreciate the suggestions. As ever, I learn something from them ;)
/Lindsay


On Fri, Mar 3, 2017 at 10:10 PM, Alexander Burger 
wrote:

> Hi Lindsay,
>
> > The code below is the recursive Gosper implementation I came up with that
> > uses very little stack. This version just emits states.
> > ...
> > Picolisp continues to impress me with its expressiveness and power.
>
> As ever, I can't resist to suggest some optimizations :)
>
>
> > (de Plot (L)
> >(map '((X) (prin (car X))) L) )
>
> (mapc prin L) would be enough.
>
>
> > (de Fn (L)
> >(let R
> >   (fish
> >  atom
> >  (mapcar
> > '((X)
> >(cond
> >   ((= X "A") A)
> >   ((= X "B") B)
> >   (T X) ) )
> > L ) )
> >   R ) )
>
> The 'let' is not necessary, as R is never used. And 'fish' is for nested
> structures, a flat list can be handled directly e.g. with 'filter' or
> 'extract'
>
>(extract '((X) (cond ((pair X)) ((=X "A") A) ..)) L)
>
> As 'A' and 'B' are free variables here, 'Fn' should be named differently,
> starting with an underscrore (see doc/ref.html#conv)). You coud try 'lint'
> or
> 'lintAll' to see what it complains.
>
> The PicoLisp naming conventions also recommend upper case first letters for
> locally bound variables. Functions defined globally like 'Plot' or 'Fn'
> should
> better start in lower case.
>
>
> > (de L-Run (L D)
> >(cond
> >   ((>= D MaxDepth) (Plot L))
> >   (T
>
> Here an 'if' is shorter than a 'cond'.
>
> ♪♫ Alex
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TC -> Loop Transformation?

[Christopher Howard]

Hi, I while ago I asked how I might somehow represent a loop as a a tail
call recursion, so as to give me the pattern I like without the call
penalties. Since nothing was forthcoming, I took a stab at it myself.
Probably my noobish attempt will be ugly to you veterans, but I was
hoping if I posted it I might get suggested improvements or alternative
approaches:

(de zip-set (L1 L2)
   (while (and L1 L2)
  (set (car L1) (car L2))
  (setq L1 (cdr L1))
  (setq L2 (cdr L2)) ) )

(de tc-recursion X
   (let (tc
  (list '@
 (list 'prog
(list 'zip-set (list 'car (list 'quote (car X))) '(rest))
'(setq Cont T)
'(throw 'TC) ) ) )
  (prog
 (setq Cont T)
 (while Cont
(setq Cont NIL)
(catch 'TC
   (run (cdr X)) ) ) ) ) )

(de tc-test ()
   (setq A 1)
   (tc-recursion (A)
  (prinl A)
  (if (>= A 10) A
 (tc (+ A 1)) ) ) )

Please include constructive suggestions along with the criticism.

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Re: JavaCode with static class methods

[Thorsten Jolitz]

Alexander Burger  writes:

Hi Joe, Hi Alex,

>> I'm experimenting a bit with the 'java' function, and the StringBuilder
>> ...
>> (java "java.lang.Math" 'sqrt 4)
>
> It needs a different call:

>: (java "java.lang.Math" 'sqrt  (-6 . 64.0))

thanks for the hints, so actually I was pretty close, just ignorant
about the peculiarities of those numeric arguments.

-- 
cheers,
Thorsten

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[Mateusz Poszwa]

Hello Mateusz Poszwa  :-)
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Thanks.

-- 
Mateusz Poszwa
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