Re: later and output

[Joh-Tob Schäg]

I am glad i could be of some help.
To be honest Linsday you do a good job for the community and a better job
than i do to be honest.
Maybe somebody can spend some time and spin this in to a draft for the
future less terse picolisp documentation.
I am currently busy with learning for pre-exames.

2017-02-25 21:58 GMT+01:00 Lindsay John Lawrence <
lawrence.lindsayj...@gmail.com>:

>
> My earlier function 'primeFactorz' had a bug! returning the wrong results
> for actual prime numbers :(
>
> : (primeFactorz 17)
> -> (3 5)   # WRONG!
>
> I have to be more careful with integer arithmetic. The corrected function
> is:
>
> (de primeFactorz (N)
>    (use Result
>       (recur (N)
>          (let (Root (inc (sqrt N))  X 2)
>             (when (gt0 (% N X))
>                (setq X 3)
>                (while
>                   (and
>                      (gt0 (% N X))
>                      (<= (inc 'X 2) Root) ) ) )
>             (setq X (if (<= X Root) X N)
>                   Result (cons X Result))
>             (unless (= X N) (recurse (/ N X))) ) )
>       Result ) )
>
> : (primeFactorz 17)
> -> (17)
>
> /Lindsay
>
> Addum: I have to say I am  impressed with how straightforward it is to
> parallelize code in picolisp!
>
> I found my bug while playing with Joh-Tob's Check function and the
> discussion on this thread really helped me to understand how to use 'later'.
>
> : (bench (CheckPrimeFactors 10000 CheckP1))
> 1.287 sec
> -> NIL
> : (bench (CheckPrimeFactors 10000 CheckP2))
> 1.310 sec
> -> NIL
> : (bench (CheckPrimeFactors 10000 CheckP1=P2))
> 1.340 sec
> -> NIL
> : (bench (CheckPrimeFactors 32 CheckOdd))
> (2 3 T 5 T 7 8 T)
> (T 11 12 13 T T T 17)
> (18 19 20 T T 23 T T)
> (T 27 28 29 30 31 32 T)
> 0.006 sec
> -> (T 27 28 29 30 31 32 T)
> : (bench (CheckPrimeFactors 32 CheckEven))
> (T T 4 T 6 T T 9)
> (10 T T T 14 15 16 T)
> (T T T 21 22 T 24 25)
> (26 T T T T T T 33)
> 0.006 sec
> -> (26 T T T T T T 33)
>
>
> Definitions: Assuming 'prime-factors' 'primeFactorz':
>
> : CheckP1
> -> ((N) (ifn (= N (apply '* (prime-factors N))) N T))
> : CheckP2
> -> ((N) (ifn (= N (apply '* (primeFactorz N))) N T))
> : CheckP1=P2
> -> ((N) (ifn (= (sort (prime-factors N)) (sort (primeFactorz N))) N T))
> : CheckOdd
> -> ((N) (if (bit? 1 (length (prime-factors N))) N T))
> : CheckEven
> -> ((N) (ifn (bit? 1 (length (prime-factors N))) N T))
>
>
> (de CheckPrimeFactors (Limit Checkit)
>    (let Lst (need 8)
>       (for (N 2 (>= Limit N))
>          (map
>             '((L)
>                (set L NIL)
>                (later L (Checkit N))
>                (inc 'N) )
>             Lst )
>          (wait NIL (full Lst))
>          (ifn (fully flg? Lst) (println Lst)) ) ) )
>
>
>
>