I suspect that the original rationale behind J adverbs might have been to
address this kind of problem, but I can't help wondering if they're a bit
past the sell-by date.

Why qualify a verb/function with a different type, if you can just compose
with the same type?
Am I missing something important here?


On 2 February 2015 at 12:21, alexgian <[email protected]> wrote:

> Hm, would that nest?
>
> Could you do
> (lambda (x)
>   (lambda(y)
>      (+ x y)))
>
> or if Scheme doesn't please you:
> /x -> /y -> x+y
>
> ?
>
>
>
> On 2 February 2015 at 10:11, Jan-Pieter Jacobs <[email protected]
> > wrote:
>
>> Well, if I'd be using it a lot, I'd write a not-so-beautiful thing
>> (which probably other people are going to phrase more eloquently) to make
>> the other code look better.
>> For instance:
>>
>> NB. lambda-ifying adverb:
>> L =: 1 : '3 : (( [: (( ''=.y'' ,~ ''''''''&([,,~) )&.>@{. , {:) < ;.  _1 )
>> m)'
>>
>> Usage:
>>
>>    times =: '|a b|a*b' L
>>    plus  =: '$x y$x+y' L NB. any separator you fancy (but space)
>>    plus 1 2
>> 3
>>    times 3 4
>> 12
>>
>>
>>
>> 2015-02-02 10:39 GMT+01:00 alexgian <[email protected]>:
>>
>> > > On a related note, lambda syntax is not really simple.
>> > > Consider:
>> > > ((lambda (x y) (+ x y)) 2 3)
>> >
>> > Well, that's *one* form of lambda syntax, viz. the Scheme variant
>> >
>> > In Haskell you'd write
>> > \x y -> x+y
>> >
>> > Hardly rocket science.  But I think the point is that that however
>> > awkwardly you may choose to codify it, lambda is brilliant in its
>> > simplicity and accessibility of understanding.  Static scoping is a
>> > no-brainer for managing complexity.
>> >
>> > I agree that the inability of abstracting J more than two levels (as
>> > already mentioned) is a serious PITA, and probably the most inexplicably
>> > klutzy piece of work in an otherwise so elegant system... I mean,
>> needing
>> > to combine tacits inside explicits, and gawdknows what other
>> work-arounds!
>> > Really?  We might have got used to it, but I doubt that many in the real
>> > world would.  But, of course, I could be wrong....
>> > ----------------------------------------------------------------------
>> > For information about J forums see http://www.jsoftware.com/forums.htm
>> >
>> ----------------------------------------------------------------------
>> For information about J forums see http://www.jsoftware.com/forums.htm
>>
>
>
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