{:))) , (<@(}.@>@{:))) (<20),(<2 3 4)
>> ┌──┬───┐
>> │22│3 4│
>> └──┴───┘
>>
>> So let's apply *that* big verb three times:
>>(((<@((>@{.) + ({.@>@{:))) , (<@(}.@>@{:))) ^:3) (<20),(<2 3 4)
>> ┌──┬┐
>&
{:))) , (<@(}.@>@{:))) (<20),(<2 3 4)
>> ┌──┬───┐
>> │22│3 4│
>> └──┴───┘
>>
>> So let's apply *that* big verb three times:
>> (((<@((>@{.) + ({.@>@{:))) , (<@(}.@>@{:))) ^:3) (<20),(<2 3 4)
>> ┌──┬┐
>
(}.@>@{:))) ^:3) (<20),(<2 3 4)
> ┌──┬┐
> │29││
> └──┴┘
>
> From here, extracting the final value of the accumulator is easy.
>
> None of this relies on anything special about the + verb, so this
> transformation should be packageable as an adverb if you're r
From: 'Pascal Jasmin' via Programming
To: [email protected]
Sent: Wed, 28 Sep 2016 20:34:43 -0400 (EDT)
Subject: Re: [Jprogramming] Learning Recursion
lispy code, as I call it, (head/rest patterns) has a bit simpler implementation
than you gave
(2&}. ,~ {. + {.@}.)(^:3) 20 2
To: [email protected]
Sent: Wednesday, September 28, 2016 7:08 PM
Subject: Re: [Jprogramming] Learning Recursion
The tricky bit is that ^: isn't a very flexible recursion scheme. The verb it
repeatedly applies effectively has to be monadic. A function on two arguments
can be turned into
student, Computer Science dept.
- Original Message -
From: Skip Cave
To: [email protected]
Sent: Tue, 27 Sep 2016 03:35:19 -0400 (EDT)
Subject: [Jprogramming] Learning Recursion
NB. I am attempting to learn recursion using ^:
NB. A simple recursion:
2+^:(3) 2
8
NB. This i
Not simply this?
+/2 3 4 2
11
Cheers,
Erling
On 2016-09-27 09:35, Skip Cave wrote:
NB. I am attempting to learn recursion using ^:
NB. A simple recursion:
2+^:(3) 2
8
NB. This is equivalent to
2+2+2+2
8
NB. What if I want to change the left argument on each recursion?
NB.
Though, I should add, induction and recursion are very similar.
There's a significant difference, though. Induction is much more like
what recursive people call "tail recursion". In other words, once a
function is done executing and you go on to the next function
evaluation, you never come back to
^: is induction, not recursion. You should use either $: or a named
routine if you want recursion.
Also, ^: is defined such that the left argument is constant and the
right argument is the result of the previous function evaluation. (Or,
initially, the initial right argument.)
Still, you can sort
NB. I am attempting to learn recursion using ^:
NB. A simple recursion:
2+^:(3) 2
8
NB. This is equivalent to
2+2+2+2
8
NB. What if I want to change the left argument on each recursion?
NB. Instead of 2 each time, I want to add 2, then 3, then 4.
NB. I know there are much easier wa
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