Hi,
for me it is not at all clear why *{1} 0* should eat (and discard) its
right argument.
In other words why would *{1} 0 *behave differently than *N 0 *with *N*
being a niladic function?
That would create new rules in the APL syntax without a need. I would
rather opt for David's
"principle of least surprises" than for Dyalog compatibility in this case.
/// Jürgen
On 08/07/2014 10:43 AM, Elias Mårtenson wrote:
Jay,
That makes sense. So the only benefit of the GNU APL approach is that
it allows the definition of niladic functions by assigning from a lambda.
My personal opinion is that that's barely a benefit, and that the
Dyalog approach is much better.
Perhaps Jürgen is willing to reconsider?
Regards,
Elias
On 7 August 2014 16:35, Jay Foad <jay.f...@gmail.com
<mailto:jay.f...@gmail.com>> wrote:
Elias,
There is no such thing as a niladic lambda in Dyalog.
In Dyalog "niladic lambda functions [are] not [...] allowed at all.
Instead, they [are] interpreted as monadic functions that ignore their
argument."
So {1} is a monadic function. You can evaluate it by applying it
to an argument:
{1}0
1
(Actually in Dyalog lambdas are not monadic or dyadic. They are all
"ambivalent". If they do not refer to ⍺ then any left argument will be
ignored.)
Jay.
On 7 August 2014 09:09, Elias Mårtenson <loke...@gmail.com
<mailto:loke...@gmail.com>> wrote:
> Jay,
>
> I also noticed that Dyalog does not allow self-evaluation of niladic
> lambdas. I.e. the expression {1} on its own does not evaluate to
1, but
> rather to something else (it's displayed as {1}, and I'm not
sure you can do
> anything with it other than assigning it to a variable).
>
> Regards,
> Elias
>
>
> On 7 August 2014 16:00, Jay Foad <jay.f...@gmail.com
<mailto:jay.f...@gmail.com>> wrote:
>>
>> On 6 August 2014 14:15, Elias Mårtenson <loke...@gmail.com
<mailto:loke...@gmail.com>> wrote:
>> > My suggestion is that niladic lambda functions will not be
allowed at
>> > all.
>> > Instead, they will be interpreted as monadic functions that
ignore their
>> > argument.
>>
>> That's consistent with the behaviour of Dyalog.
>>
>> Jay.
>
>
