Re: Future of PicoLisp?

[Edgaras]

Just a lurker passing by:

Personally I'm much less excited about things like pip or node.js packages.
While I get their appeal often times you end up with quite a nonses like
node.js left-pad issue of year or so ago. In my eyes it promotes a kinda of
"shatered into milion pieces" situation. I'm much more keen on how things are
in C land - go get stuff yourself :). Which somewhat prevents "dependacny
creep".

On Fri, Feb 24, 2017 at 09:02:57AM +0100, Jakob Eriksson wrote:
> And I would be interested in working on a package or module system similar to 
> "pip" for Python.
> 
> I must confess that most discussions about namespaces etc on this list is way 
> over my head... however could I be on the right track if I were to assume 
> that using "local" in such modules would be a good start, so as to only 
> export deliberately exposed symbols from a package?
> 
> 
> 
> 
> > 24 feb. 2017 kl. 08:45 skrev Alexander Burger :
> > 
> > Hi Erik,
> > 
> > thanks for the long post!
> > 
> > Just in short:
> > 
> >> 'Learn PicoLisp the Hard Way'
> > 
> > I totally agree. This would be a great project, I'm ready to join.
> > Same for Stack Overflow support.
> > 
> > 
> >> And let's make sure said landing page is served over HTTPS. It's 2017.
> > 
> > Yes, yes, I know ;) In fact, it is on my todo list since half a year.
> > 
> > I want to use Let's Encrypt, as I already do on another server. However, the
> > picolisp.com server is currently a mix of Wheezy, Jessie and Stretch, and
> > whatever I tried to get the certbot running resulted in a storm of Python
> > package mismatch error messages. No way .. I gave up, and decided to wait 
> > until
> > Debian Stretch is stable and thus available from my provider.
> > 
> > ♪♫ Alex
> > -- 
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> 
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Re: Copy/Clone a 'job

[Lindsay John Lawrence]

Thanks for the suggestion Joe.

Other than copy-paste examples, I haven't played much with either #oop and
#dbase in picolisp. It is definitely on my list ;)

I've been trying to get a good understanding of variable scope, state and
lifetime. Especially with functions that have the side-effect of
manipulating globals, or lists, 'destructively'.  Once I have that, I think
the symbol management in picolisp's oop and db facets should be easy enough
to grasp.

My hex digit example was a bit contrived... I was actually working through
this https://rosettacode.org/wiki/Pi#PicoLisp, and after reading the
referenced source at
http://www.cs.ox.ac.uk/jeremy.gibbons/publications/spigot.pdf,  tweaked it
to return the digits in hexadecimal (see code below).

To get off-topic a bit, philosophically

I am a proponent of minimalism in coding and algorithms/tools that make it
easy to generate, manipulate or filter 'streams.

Hence.. picolisp!

https://en.wikipedia.org/wiki/Unix_philosophy: "Write programs that do one
thing and do it well. Write programs to work together. Write programs to
handle text streams, because that is a universal interface."  --- Doug
Mcllroy

I think what Mcllroy could have said there, instead of text streams, was
'symbol lists' ;)

/Lindsay


# From https://rosettacode.org/wiki/Pi#PicoLisp
# But, return the digits in hexadecimal and provide a way to 'reset' the
spigot.

(de makeHexaPi ()
(curry ((Q . 1) (R . 0) (S . 1) (K . 1) (N . 3) (L . 3)) ()
  (while (>= (- (+ R (* 4 Q)) S) (* N S))
 (mapc set '(Q R S K N L)
(list
   (* Q K)
   (* L (+ R (* 2 Q)))
   (* S L)
   (inc K)
   (/ (+ (* Q (+ 2 (* 7 K))) (* R L)) (* S L))
   (+ 2 L) ) ) )
  (prog1 N
 (let M (- (/ (* 16 (+ R (* 3 Q))) S) (* 16 N))
(setq Q (* 16 Q)  R (* 16 (- R (* N S)))  N M) ) ) ) )



: (def 'pi16Digit (makeHexaPi))
-> pi16Digit
: (pack (make (do 8 (link  (hex (pi16Digit))
-> "3243F6A8"
: (pack (make (do 8 (link  (hex (pi16Digit))
-> "885A308D"

: (off pi16Digit)
-> NIL
: (def 'pi16Digit (makeHexaPi))
-> pi16Digit
: (pack (make (do 16 (link  (hex (pi16Digit))
-> "3243F6A8885A308D"



On Sun, Feb 26, 2017 at 4:30 AM, Joe Bogner  wrote:

> Hi Lindsay,
>
> It looks like you are using job primarily to retain the value of N
> between invocations. Is that true? Just curious, why not move the loop
> inside of hexSpigot instead of looping outside of it? Another option
> to consider if you want the behavior of being able to increment the
> hexSpigot at any point - use a pil class
> (http://software-lab.de/doc/ref.html#oop)
>
>
>
> Thanks,
> Joe
>

Re: BBWT

[Alexander Burger]

On Sun, Feb 26, 2017 at 06:00:28PM +0100, Joh-Tob Schäg wrote:
> > Yes, gotta love lisp for the ability to do this (and other things). :)
> >
> But more often than not this features are not required in practice. Sadly
> it is just cool and not significant.  :(

I would say it is very significant. Factoring the code gives shorter, faster and
more readable programs by avoiding duplicated code and redundancies.

♪♫ Alex
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Re: Lifespan of memory of parameters

[Christopher Howard]

Thanks for the quick reply, and the great info I get on this list. Maybe
more to the point would be a function like so:

(de foo (Lst)
  # some kind of escape condition usually here
  (foo (modified-copy Lst)) )

Where modified-copy is a function that returns a *new* list.

After, say, the tenth time foo is called, are there now ten lists in memory?

Rationale: In some cases it feels safer and more natural to implement
the algorithm as a recursive algorithm where you are always passing
around modified copies of the data.

Or do we have to use loops and set a variable each iteration?

On 02/25/2017 11:06 PM, Alexander Burger wrote:
> On Sun, Feb 26, 2017 at 08:31:37AM +0100, Alexander Burger wrote:
>>   (let A (bar (copy Lst))
>>  (off Lst)
>>  (doSomethingWithTheCopy)
>>  ...
>>
>> With (off Lst) *one* refernce to the list is cleared, but the list will be
>> garbage collected only when the *last* reference is gone, which is not under
>> control of 'foo'.
> 
> Of course, if you *know* that 'Lst' is not owned by anybody else, i.e. it was
> freshly created by reading or list manipulations etc., you don't need to copy 
> it
> at all in the first place. 'copy' is used rather seldom, in cases where you 
> want
> to do destructive operations on list that might be owned by someone else.
> 
> ♪♫ Alex
> 

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Re: BBWT

[Joh-Tob Schäg]

> Yes, gotta love lisp for the ability to do this (and other things). :)
>
But more often than not this features are not required in practice. Sadly
it is just cool and not significant.  :(


2017-02-26 17:06 GMT+01:00 Rick Hanson :

> A bit off-topic, but I like how this transformation
>
> On 25 Feb 2017, 09:40:43 +0100, Alexander Burger wrote:
> >(if (not (cdr W))
> >   (Put C (car W))
> >   (Put (car (cdr W)) (car W)) )
> > ->
> >(Put
> >   (ifn (cdr W) C (cadr W))
> >   (car W) )
>
> reminds me of factoring in high school algebra.
>
>xy + xz
> ->
>x(y + z)
>
> Yes, gotta love lisp for the ability to do this (and other things). :)
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Re: BBWT

[Rick Hanson]

A bit off-topic, but I like how this transformation

On 25 Feb 2017, 09:40:43 +0100, Alexander Burger wrote:
>(if (not (cdr W))
>   (Put C (car W))
>   (Put (car (cdr W)) (car W)) )
> ->
>(Put
>   (ifn (cdr W) C (cadr W))
>   (car W) )

reminds me of factoring in high school algebra.

   xy + xz
->
   x(y + z)

Yes, gotta love lisp for the ability to do this (and other things). :)
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Re: Copy/Clone a 'job

[Joe Bogner]

Hi Lindsay,

It looks like you are using job primarily to retain the value of N
between invocations. Is that true? Just curious, why not move the loop
inside of hexSpigot instead of looping outside of it? Another option
to consider if you want the behavior of being able to increment the
hexSpigot at any point - use a pil class
(http://software-lab.de/doc/ref.html#oop)



Thanks,
Joe

On Sun, Feb 26, 2017 at 5:03 AM, Lindsay John Lawrence
 wrote:
> Thanks Alex,
>
> I'll have to play with your solution a bit. I don't quite follow how the
> global is working there in conjunction with 'job and 'off.
>
> However, after banging around on this for a couple of hours, trying 'copy',
> various auxillary functions to return the quoted 'job, etc I was at my wits
> end...when just a few minutes ago, I remembered where the mail list had
> discussed 'job most recently... over 'curry!
>
> This seems to do what I want as well...
>
> : (pp 'getHexSpigot)
> (de getHexSpigot NIL
>(curry
>   ((N))
>   NIL
>   (default N '(0))
>   (prog1
>  (hex (% (car N) 16))
>  (setq N (cons (+ 1 (car N)) N)) ) ) )
> -> getHexSpigot
>
> Now I can do this...
>
> : (def 'hexSpigot1 (getHexSpigot))
> -> hexSpigot1
> : (def 'hexSpigot2 (getHexSpigot))
> -> hexSpigot2
>
> : (do 8 (prin (hexSpigot1)))
> 01234567-> "7"
> : (do 16 (prin (hexSpigot2)))
> 0123456789ABCDEF-> "F"
>
> : hexSpigot1
> -> (NIL (job '((N 8 7 6 5 4 3 2 1 0)) (default N '(0)) (prog1 (hex (% (car
> N) 16)) (setq N (cons (+ 1 (car N)) N)
> : hexSpigot2
> -> (NIL (job '((N 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0)) (default N
> '(0)) (prog1 (hex (% (car N) 16)) (setq N (cons (+ 1 (car N)) N)
>
> : (off hexSpigot1)
> : (off hexSpigot2)
>
>
> /Lindsay
>
>
>
>
> On Sun, Feb 26, 2017 at 1:19 AM, Alexander Burger 
> wrote:
>>
>> Hi Lindsay,
>>
>> > (de hexSpigot NIL
>> >(job '((N))
>> > ...
>> > : (do 32 (prin (hexSpigot)))
>> > ...
>> > 0123456789ABCDEF0123456789ABCDEF-> "F"
>> > ...
>> > : (pp 'hexSpigot)
>> > (de hexSpigot NIL
>> >(job
>> >   '((N 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13
>> > 12
>> > 11 10 9 8 7 6 5 4 3 2 1 0 ) )
>> > ...
>> > The job vars are being modified and the list N is growing.. using ever
>> > greater amounts of memory. If I want to reset the spigot, or even clone
>> > it
>> > to have more than one, how would I do that?
>>
>> The simplest is to use a global:
>>
>>(setq *HexSpigot '((N)))
>>
>>(de hexSpigot NIL
>>   (job *HexSpigot
>>  ...
>>
>> and later just do the 'setq' again.
>>
>>
>> BTW, for an expression like
>>
>>(ifn N (setq N (0)))
>>
>> there is 'default'
>>
>>(default N (0))
>>
>> So the above could be made a bit easier:
>>
>>(off *HexSpigot)
>>
>>(de hexSpigot NIL
>>   (job (default *HexSpigot '((N . (0
>>  (prog1
>> (hex (% (car N) 16))
>> (setq N (cons (+ 1 (car N)) N)) ) ) )
>>
>>(do 32 (prin (hexSpigot)))
>>(off *HexSpigot)
>>(do 32 (prin (hexSpigot)))
>>
>> i.e. just call 'off' to reset it :)
>>
>> ♪♫ Alex
>> --
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>
>
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Re: Copy/Clone a 'job

[Alexander Burger]

Hi Lindsay,

> I'll have to play with your solution a bit. I don't quite follow how the
> global is working there in conjunction with 'job and 'off.

There is nothing mysterious about it.

'job' evaluates its first argument. So there is absolutely no difference whether
you quote that argument

   (job '((N)) ...

or pass it in a variable

   (setq Var '((N)))
   (job Var ...

♪♫ Alex
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Re: Copy/Clone a 'job

[Lindsay John Lawrence]

Thanks Alex,

I'll have to play with your solution a bit. I don't quite follow how the
global is working there in conjunction with 'job and 'off.

However, after banging around on this for a couple of hours, trying 'copy',
various auxillary functions to return the quoted 'job, etc I was at my wits
end...when just a few minutes ago, I remembered where the mail list had
discussed 'job most recently... over 'curry!

This seems to do what I want as well...

: (pp 'getHexSpigot)
(de getHexSpigot NIL
   (curry
  ((N))
  NIL
  (default N '(0))
  (prog1
 (hex (% (car N) 16))
 (setq N (cons (+ 1 (car N)) N)) ) ) )
-> getHexSpigot

Now I can do this...

: (def 'hexSpigot1 (getHexSpigot))
-> hexSpigot1
: (def 'hexSpigot2 (getHexSpigot))
-> hexSpigot2

: (do 8 (prin (hexSpigot1)))
01234567-> "7"
: (do 16 (prin (hexSpigot2)))
0123456789ABCDEF-> "F"

: hexSpigot1
-> (NIL (job '((N 8 7 6 5 4 3 2 1 0)) (default N '(0)) (prog1 (hex (% (car
N) 16)) (setq N (cons (+ 1 (car N)) N)
: hexSpigot2
-> (NIL (job '((N 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0)) (default N
'(0)) (prog1 (hex (% (car N) 16)) (setq N (cons (+ 1 (car N)) N)

: (off hexSpigot1)
: (off hexSpigot2)


/Lindsay




On Sun, Feb 26, 2017 at 1:19 AM, Alexander Burger 
wrote:

> Hi Lindsay,
>
> > (de hexSpigot NIL
> >(job '((N))
> > ...
> > : (do 32 (prin (hexSpigot)))
> > ...
> > 0123456789ABCDEF0123456789ABCDEF-> "F"
> > ...
> > : (pp 'hexSpigot)
> > (de hexSpigot NIL
> >(job
> >   '((N 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12
> > 11 10 9 8 7 6 5 4 3 2 1 0 ) )
> > ...
> > The job vars are being modified and the list N is growing.. using ever
> > greater amounts of memory. If I want to reset the spigot, or even clone
> it
> > to have more than one, how would I do that?
>
> The simplest is to use a global:
>
>(setq *HexSpigot '((N)))
>
>(de hexSpigot NIL
>   (job *HexSpigot
>  ...
>
> and later just do the 'setq' again.
>
>
> BTW, for an expression like
>
>(ifn N (setq N (0)))
>
> there is 'default'
>
>(default N (0))
>
> So the above could be made a bit easier:
>
>(off *HexSpigot)
>
>(de hexSpigot NIL
>   (job (default *HexSpigot '((N . (0
>  (prog1
> (hex (% (car N) 16))
> (setq N (cons (+ 1 (car N)) N)) ) ) )
>
>(do 32 (prin (hexSpigot)))
>(off *HexSpigot)
>(do 32 (prin (hexSpigot)))
>
> i.e. just call 'off' to reset it :)
>
> ♪♫ Alex
> --
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>

Re: Copy/Clone a 'job

[Alexander Burger]

Hi Lindsay,

> (de hexSpigot NIL
>(job '((N))
> ...
> : (do 32 (prin (hexSpigot)))
> ...
> 0123456789ABCDEF0123456789ABCDEF-> "F"
> ... 
> : (pp 'hexSpigot)
> (de hexSpigot NIL
>(job
>   '((N 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12
> 11 10 9 8 7 6 5 4 3 2 1 0 ) )
> ...
> The job vars are being modified and the list N is growing.. using ever
> greater amounts of memory. If I want to reset the spigot, or even clone it
> to have more than one, how would I do that?

The simplest is to use a global:

   (setq *HexSpigot '((N)))

   (de hexSpigot NIL
  (job *HexSpigot
 ...

and later just do the 'setq' again.


BTW, for an expression like

   (ifn N (setq N (0)))

there is 'default'

   (default N (0))

So the above could be made a bit easier:

   (off *HexSpigot)

   (de hexSpigot NIL
  (job (default *HexSpigot '((N . (0
 (prog1
(hex (% (car N) 16))
(setq N (cons (+ 1 (car N)) N)) ) ) )

   (do 32 (prin (hexSpigot)))
   (off *HexSpigot)
   (do 32 (prin (hexSpigot)))

i.e. just call 'off' to reset it :)

♪♫ Alex
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Copy/Clone a 'job

[Lindsay John Lawrence]

Hi,

How would I copy|clone, reinitialize or dispose of a 'job' function?

For example, given

(de hexSpigot NIL
   (job '((N))
  (ifn N (setq N '(0)))
  (prog1
 (hex (% (car N) 16))
 (setq N (cons (+ 1 (car N)) N)) ) ) )

I can then do..

: (do 32 (prin (hexSpigot)))

0123456789ABCDEF0123456789ABCDEF-> "F"

Now, hexSpigot something like this...

: (pp 'hexSpigot)
(de hexSpigot NIL
   (job
  '((N 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12
11 10 9 8 7 6 5 4 3 2 1 0 ) )
  (ifn N (setq N '(0)))
  (prog1
 (hex (% (car N) 16))
 (setq N (cons (+ 1 (car N)) N)) ) ) )



The job vars are being modified and the list N is growing.. using ever
greater amounts of memory. If I want to reset the spigot, or even clone it
to have more than one, how would I do that?


/Lindsay

Re: Lifespan of memory of parameters

[Alexander Burger]

On Sun, Feb 26, 2017 at 08:31:37AM +0100, Alexander Burger wrote:
>   (let A (bar (copy Lst))
>  (off Lst)
>  (doSomethingWithTheCopy)
>  ...
> 
> With (off Lst) *one* refernce to the list is cleared, but the list will be
> garbage collected only when the *last* reference is gone, which is not under
> control of 'foo'.

Of course, if you *know* that 'Lst' is not owned by anybody else, i.e. it was
freshly created by reading or list manipulations etc., you don't need to copy it
at all in the first place. 'copy' is used rather seldom, in cases where you want
to do destructive operations on list that might be owned by someone else.

♪♫ Alex
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