Very well said.
On 27/12/2014 07:46, Aai wrote:
Sorry for jumping in late.
The Haskell expression you showed here is called a list comprehansion
which can be easily formulated as
map f xs
and this is in J simply:
f xs
Jon Hough schreef op 26-12-14 om 17:04:
In Haskell (and other
Hi Aai,
I see what you are saying, but I would say that implicitly inside f there is
some sort of such that syntax.
My motivation for asking for a such that / where construct is to create
computable math definitions, as in Haskell.
for example, if I want the set (or group):
{ x e. Sym(4) |
Hello John,
just interpreting what you mean (but I may misunderstand it completely).
With a list comprehension you can formulate:
(just a simple example)
Prelude take 6 $ [ (^2) x | x - [0..], 0 == x `mod` 2]
[0,4,16,36,64,100]
In J:
(*:#~0=2|) i.12
0 4 16 36 64 100
Perhaps something
Hi Aai,
I'm sorry, we may be talking past each other. You are correct abut list
comprehensions, but I am interested in being able to get a such that idea in
J, to make translating math definitions {A | B} (A such that B) into computable
J.
This isn't to make anything computationally faster or
If I understand properly, the Haskell concept of such that is
roughly analogous to the J concept of verb rank (which is a built in
property of all J verbs).
If this is the case, maybe what you want is already there?
Thanks,
--
Raul
On Sat, Dec 27, 2014 at 10:01 AM, Jon Hough
It seems that such that is indistinguishable (to me) with select. While I do
not use a select utility adverb (I write out a # expression each time),
making these utility adverbs is a great step in learning J, and making the
language fit the concepts you already understand in your mind. With
Ok, I misinterpreted this enormously (I was just focused on the Haslell
expression you started with). It would be nice if you could illustrate
your last mail with an example in Haskell (but that's specifically for me).
You started with the Haskell expression
[ f x | x - xs ]
and described
https://www.haskell.org/haskellwiki/List_comprehension
On 27 December 2014 at 18:31, Aai agroeneveld...@gmail.com wrote:
Ok, I misinterpreted this enormously (I was just focused on the Haslell
expression you started with). It would be nice if you could illustrate your
last mail with an
A purely haskell discussion, without any J code, probably belongs in
the chat forum instead of this one.
That said, I think the point was not list comprehensions, but a
question about what aspect was being referred to *instead of* list
comprehensions.
That is, if I comprehend the messages which
Or:
f=: [: *: : #~ 2 | ]
f i.12
0 4 16 36 64 100
Linda
-Original Message-
From: programming-boun...@forums.jsoftware.com
[mailto:programming-boun...@forums.jsoftware.com] On Behalf Of Aai
Sent: Saturday, December 27, 2014 12:32 PM
To: programm...@jsoftware.com
Subject: Re:
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