Re: The behaviour of arg

[Henrik Sarvell]

In this case I simply use (arg 1), I just wanted to check if perhaps
(arg) defaulted to (arg 1) if no prior next had been called.

On Sat, Nov 12, 2016 at 7:45 AM, Alexander Burger  wrote:
> Hi Henrik, Andreas,
>
>> I guess this is the unforgiving punishment for calling (arg) without
>> calling (next) previously, consider the reference:
>> "If cnt is not given, the value that was returned from the last call
>> to next" -> no previous call to next -> invalid usage -> punishment
>
> Exactly! In fact, 'arg' should check such illegal usage. It is a
> secondary function, and not much used.
>
>
> The main workhorse for variable arguments is 'next', and often
> all that is needed:
>
>: (de f @
>   (while (next)
>  (println @) ) )
>
>-> f
>:  (f 1 2 3)
>1
>2
>3
>
> The purpose of 'arg' is to avoid the overhead of a local variable if
> the value is used more than once.
>
> ♪♫ Alex
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Re: The behaviour of arg

[Alexander Burger]

Hi Henrik, Andreas,

> I guess this is the unforgiving punishment for calling (arg) without
> calling (next) previously, consider the reference:
> "If cnt is not given, the value that was returned from the last call
> to next" -> no previous call to next -> invalid usage -> punishment

Exactly! In fact, 'arg' should check such illegal usage. It is a
secondary function, and not much used.


The main workhorse for variable arguments is 'next', and often
all that is needed:

   : (de f @
  (while (next)
 (println @) ) )

   -> f
   :  (f 1 2 3)
   1
   2
   3

The purpose of 'arg' is to avoid the overhead of a local variable if
the value is used more than once.

♪♫ Alex
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RE: The behaviour of arg

[andreas]

Hi Henrik

Nice to read something from you, also the other emails, I'm looking forward to 
check out your new code!

I immediately get SEGFAULT when calling your atst. Running pil64 on Linux 64bit 
(ubuntu).
On which OS are you?

I guess this is the unforgiving punishment for calling (arg) without calling 
(next) previously, consider the reference:
"If cnt is not given, the value that was returned from the last call to next" 
-> no previous call to next -> invalid usage -> punishment

The following works for me:

(de atst @
   (next)
   (println (arg)) )

arg seems to be a special purpose function.

if you just want to have the whole list of arguments, use (rest) instead:

: (de atst @
   (println (rest) ) )
-> atst
: (atst 1 2 3)
(1 2 3)
-> (1 2 3)

Greatings,
beneroth




- Original Message -
From: Henrik Sarvell [mailto:hsarv...@gmail.com]
To: picolisp@software-lab.de
Sent: Fri, 11 Nov 2016 23:08:04 +0100
Subject: The behaviour of arg

Hi Alex and list.

If I do like this:

(de atst @
   (println (arg)) )
(atst 1 2 3)
(bye)

I never reach (bye) and I can't even abort with ctrl-c or d (had to
kill -9), is there a reason for this unforgiving punishment of arg
abuse or did I find some minor bug?
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The behaviour of arg

[Henrik Sarvell]

Hi Alex and list.

If I do like this:

(de atst @
   (println (arg)) )
(atst 1 2 3)
(bye)

I never reach (bye) and I can't even abort with ctrl-c or d (had to
kill -9), is there a reason for this unforgiving punishment of arg
abuse or did I find some minor bug?
-- 
UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe