I agree that M is simple. It reminds me of the definition of X and Y
that has been previously posted. How does it compare to that?
Quick search found a definition like this:
Y =: (&{::)(@:])
X =: (&{::)(@:[)
but it could also be defined as
X=: @[
Y=: @]
3 4 (+:X + -:Y) 2 4
7 10
Regarding the ambivalence and not always a domain error, smart fork
could always use https://github.com/Pascal-J/type-system-j to
determine whether it should be treated monadic or dyadic (I realize
I'm going a bit overboard here)....
On Thu, Dec 10, 2015 at 3:16 PM, 'Pascal Jasmin' via Programming
<[email protected]> wrote:
> took me a few years to realize that dyadic +:is not always a domain error.
> (its a boolean op). Nearly all of the builtins are ambivalent.
>
>
> I think M is simple and clean enough to use, and I like that you can change
> the X or Y reference by just removing/adding ~.
>
> That's just me, but I thought I'd share.
>
>
>
> ----- Original Message -----
> From: Joe Bogner <[email protected]>
> To: [email protected]
> Sent: Thursday, December 10, 2015 1:15 PM
> Subject: Re: [Jprogramming] dyadic J
>
> Interesting. I'm not sure if M is worth it over @] due to potential
> naming conflicts and ambiguity in the code .@] is very clear
>
> It got me thinking that it might be interesting (albeit probably not
> overly useful) to have a 'smart fork' adverb that could figure out
> that its arguments are monadic and bind them appropriately
>
> This starts to show what I mean
> fork=:(2 : 'u@[ + v@]')
>
> 3 4 (+: fork -:) 2 4
> 7 10
>
> The + would need to be extracted, so it would need to be
>
> 3 4 (+: + -:) fork 2 4
>
> I don't think that's possible without using gerunds..
>
> fork=: (1 :'(0{:: u);''@'';''['';(1&{::u);(2{:: u);''@'';'']''') (1 : 'u `:6')
>
> +:`+`-: fork
> +:@[ + -:@]
>
> 3 4 +:`+`-: fork 2 4
> 7 10
>
> fork could be enhanced to detect whether the tines are monadic and
> only apply the @[ and @] if so
>
> not sure how useful it is, but fun to play with
>
>
>
>
> On Thu, Dec 10, 2015 at 12:11 PM, 'Pascal Jasmin' via Programming
> <[email protected]> wrote:
>> Here is another approach to simplifying J and meeting dyadic J goals without
>> verb definitions:
>>
>> M =: @]
>>
>>
>> 3 4 (+:M~ + -:M) 2 4
>> 7 10
>> (+: M~ + -: M) 2 4
>> 5 10
>>
>>
>>
>> ~ (swap) basically works like @[ on a monad that is defined to ignore x
>> rather than return error.
>>
>> M or M~ is easier to type than @:] or @:[ too.
>>
>>
>> T =: &{(>@)
>> NB. double adverb version of @:
>> at =: 1 : 'u 1 :''2 : ''''u (v@:) '''' u'''
>>
>>
>>
>>
>> 3 2 (1 T M~ + 0 1 T M +: at) 2 3 4
>> 6 8
>>
>> ----- Original Message -----
>> From: Jose Mario Quintana <[email protected]>
>> To: Programming forum <[email protected]>
>> Sent: Thursday, December 3, 2015 11:04 AM
>> Subject: Re: [Jprogramming] dyadic J
>>
>> Pascal wrote:
>>
>> "There is a addon called general/primitives that provides shadow names for
>> everything."
>>
>> However, trying to provide a shadow name for $: is futile.
>>
>>
>> Pascal wrote:
>>
>> 'A recent point of conversion of mine is that u@:v is both easier to read
>> and edit/expand and easier to see subresults by cutting out parts of an @
>> train "s@t@u@v" even if its u@:(v) compared to [: u v.'
>>
>> Welcome to a very exclusive club ;)
>>
>>
>> Linda wrote:
>> "
>> Pascal and others. I am curious to know if you find tacit code easy to read.
>>
>> cr=:([ = [: +/ [: |: #~ #: [: i. ^) #"2 #~ #: [: i. ^
>> divy=:([: ,. [: <"1 '*' $~ ] ,~ [: <. %) , [: < '*' $~ [ - ] * [: <. %
>>
>> Those two tacit lines seem hard to translate for me. Instead I find the
>> expressions below are quite easy to follow.
>>
>> cr=: 13 :'(x= +/ |:(y#x)#:i.x^y) #"2 (y#x)#:i.x^y'
>> divy=: 13 :'(,.<"1((<.x%y),y)$''*''),<(x-y*<.x%y)$''*'''
>> "
>>
>> I submit that it is a matter of familiarity. Granted, forum members are
>> likely more familiar with explicit rather than tacit reading and writing
>> (then again, most programmers are more familiar with one element at a time
>> as opposed to array processing).
>>
>> Personally, armed with the boxed representation of a verb, I can typically
>> see effortlessly how the data flows given a tacit verb and its
>> argument(s). This does not surprise me since the interpreter’s
>> representation of a verb is closely related to the boxed representation (if
>> I recall correctly).
>>
>> Moreover, tacit forms facilitate the manual, or automatic, symbolic
>> manipulation and simplification of tacit forms. For example,
>>
>> cr=:([ = [: +/ [: |: #~ #: [: i. ^) #"2 #~ #: [: i. ^
>>
>> cr
>> ([ = [: +/ [: |: #~ #: [: i. ^) #"2 #~ #: [: i. ^
>> ┌─────────────────────────────────────────────┬───────┬────────────────────┐
>> │┌─┬─┬───────────────────────────────────────┐│┌─┬─┬─┐│┌─────┬──┬─────────┐│
>> ││[│=│┌──┬─────┬────────────────────────────┐│││#│"│2│││┌─┬─┐│#:│┌──┬──┬─┐││
>> ││ │ ││[:│┌─┬─┐│┌──┬──┬────────────────────┐│││└─┴─┴─┘│││#│~││ ││[:│i.│^│││
>> ││ │ ││ ││+│/│││[:│|:│┌─────┬──┬─────────┐││││ ││└─┴─┘│ │└──┴──┴─┘││
>> ││ │ ││ │└─┴─┘││ │ ││┌─┬─┐│#:│┌──┬──┬─┐│││││ │└─────┴──┴─────────┘│
>> ││ │ ││ │ ││ │ │││#│~││ ││[:│i.│^││││││ │ │
>> ││ │ ││ │ ││ │ ││└─┴─┘│ │└──┴──┴─┘│││││ │ │
>> ││ │ ││ │ ││ │ │└─────┴──┴─────────┘││││ │ │
>> ││ │ ││ │ │└──┴──┴────────────────────┘│││ │ │
>> ││ │ │└──┴─────┴────────────────────────────┘││ │ │
>> │└─┴─┴───────────────────────────────────────┘│ │ │
>> └─────────────────────────────────────────────┴───────┴────────────────────┘
>>
>> NB. Regardless of the nature of the arguments...
>>
>> NB. Automatically,
>>
>> cr f. decap ala NB. Wicked Jx adverbs for decapitating and associating
>> @:s to the left
>> ([ = +/@:|:@:(#~ #: i.@:^)) #"2 #~ #: i.@:^
>> ┌─────────────────────────────────────────────┬───────┬────────────────────┐
>> │┌─┬─┬───────────────────────────────────────┐│┌─┬─┬─┐│┌─────┬──┬─────────┐│
>> ││[│=│┌─────────────┬──┬────────────────────┐│││#│"│2│││┌─┬─┐│#:│┌──┬──┬─┐││
>> ││ │ ││┌─────┬──┬──┐│@:│┌─────┬──┬─────────┐│││└─┴─┴─┘│││#│~││ ││i.│@:│^│││
>> ││ │ │││┌─┬─┐│@:│|:││ ││┌─┬─┐│#:│┌──┬──┬─┐││││ ││└─┴─┘│ │└──┴──┴─┘││
>> ││ │ ││││+│/││ │ ││ │││#│~││ ││i.│@:│^│││││ │└─────┴──┴─────────┘│
>> ││ │ │││└─┴─┘│ │ ││ ││└─┴─┘│ │└──┴──┴─┘││││ │ │
>> ││ │ ││└─────┴──┴──┘│ │└─────┴──┴─────────┘│││ │ │
>> ││ │ │└─────────────┴──┴────────────────────┘││ │ │
>> │└─┴─┴───────────────────────────────────────┘│ │ │
>> └─────────────────────────────────────────────┴───────┴────────────────────┘
>>
>> NB. Manually,
>>
>> [ (([ = +/@:|:@:]) #"2 ]) #~ #: i.@:^ NB. Distributing (#~ #: i.@:^)
>> [ (([ = +/@:|:@:]) #"2 ]) #~ #: i.@:^
>> ┌─┬──────────────────────────────────────┬────────────────────┐
>> │[│┌──────────────────────────┬───────┬─┐│┌─────┬──┬─────────┐│
>> │ ││┌─┬─┬────────────────────┐│┌─┬─┬─┐│]│││┌─┬─┐│#:│┌──┬──┬─┐││
>> │ │││[│=│┌─────────────┬──┬─┐│││#│"│2││ ││││#│~││ ││i.│@:│^│││
>> │ │││ │ ││┌─────┬──┬──┐│@:│]│││└─┴─┴─┘│ │││└─┴─┘│ │└──┴──┴─┘││
>> │ │││ │ │││┌─┬─┐│@:│|:││ │ │││ │ ││└─────┴──┴─────────┘│
>> │ │││ │ ││││+│/││ │ ││ │ │││ │ ││ │
>> │ │││ │ │││└─┴─┘│ │ ││ │ │││ │ ││ │
>> │ │││ │ ││└─────┴──┴──┘│ │ │││ │ ││ │
>> │ │││ │ │└─────────────┴──┴─┘││ │ ││ │
>> │ ││└─┴─┴────────────────────┘│ │ ││ │
>> │ │└──────────────────────────┴───────┴─┘│ │
>> └─┴──────────────────────────────────────┴────────────────────┘
>>
>> [ (( = +/@:|: ) #"2 ]) #~ #: i.@:^ NB. Hook form
>> [ ((= +/@:|:) #"2 ]) #~ #: i.@:^
>> ┌─┬─────────────────────────────┬────────────────────┐
>> │[│┌─────────────────┬───────┬─┐│┌─────┬──┬─────────┐│
>> │ ││┌─┬─────────────┐│┌─┬─┬─┐│]│││┌─┬─┐│#:│┌──┬──┬─┐││
>> │ │││=│┌─────┬──┬──┐│││#│"│2││ ││││#│~││ ││i.│@:│^│││
>> │ │││ ││┌─┬─┐│@:│|:│││└─┴─┴─┘│ │││└─┴─┘│ │└──┴──┴─┘││
>> │ │││ │││+│/││ │ │││ │ ││└─────┴──┴─────────┘│
>> │ │││ ││└─┴─┘│ │ │││ │ ││ │
>> │ │││ │└─────┴──┴──┘││ │ ││ │
>> │ ││└─┴─────────────┘│ │ ││ │
>> │ │└─────────────────┴───────┴─┘│ │
>> └─┴─────────────────────────────┴────────────────────┘
>>
>> NB. Given the nature of the arguments...
>>
>> [ (( = +/@:|: ) # ]) #~ #: i.@:^ NB. Redundant "2
>> [ ((= +/@:|:) # ]) #~ #: i.@:^
>> ┌─┬───────────────────────┬────────────────────┐
>> │[│┌─────────────────┬─┬─┐│┌─────┬──┬─────────┐│
>> │ ││┌─┬─────────────┐│#│]│││┌─┬─┐│#:│┌──┬──┬─┐││
>> │ │││=│┌─────┬──┬──┐││ │ ││││#│~││ ││i.│@:│^│││
>> │ │││ ││┌─┬─┐│@:│|:│││ │ │││└─┴─┘│ │└──┴──┴─┘││
>> │ │││ │││+│/││ │ │││ │ ││└─────┴──┴─────────┘│
>> │ │││ ││└─┴─┘│ │ │││ │ ││ │
>> │ │││ │└─────┴──┴──┘││ │ ││ │
>> │ ││└─┴─────────────┘│ │ ││ │
>> │ │└─────────────────┴─┴─┘│ │
>> └─┴───────────────────────┴────────────────────┘
>>
>> [ (( = +/"1 ) # ]) #~ #: i.@:^ NB. Summing the rows of a matrix
>> [ ((= +/"1) # ]) #~ #: i.@:^
>> ┌─┬─────────────────────┬────────────────────┐
>> │[│┌───────────────┬─┬─┐│┌─────┬──┬─────────┐│
>> │ ││┌─┬───────────┐│#│]│││┌─┬─┐│#:│┌──┬──┬─┐││
>> │ │││=│┌─────┬─┬─┐││ │ ││││#│~││ ││i.│@:│^│││
>> │ │││ ││┌─┬─┐│"│1│││ │ │││└─┴─┘│ │└──┴──┴─┘││
>> │ │││ │││+│/││ │ │││ │ ││└─────┴──┴─────────┘│
>> │ │││ ││└─┴─┘│ │ │││ │ ││ │
>> │ │││ │└─────┴─┴─┘││ │ ││ │
>> │ ││└─┴───────────┘│ │ ││ │
>> │ │└───────────────┴─┴─┘│ │
>> └─┴─────────────────────┴────────────────────┘
>>
>> This latter form is the capless counterpart of the version provided by
>> Lippu Esa.
>>
>>
>>
>>
>> On Sat, Nov 28, 2015 at 2:27 AM, Linda A Alvord <[email protected]>
>> wrote:
>>
>>> Pascal and others. I am curious to know if you find tacit code easy to
>>> read.
>>>
>>> cr=:([ = [: +/ [: |: #~ #: [: i. ^) #"2 #~ #: [: i. ^
>>> divy=:([: ,. [: <"1 '*' $~ ] ,~ [: <. %) , [: < '*' $~ [ - ] * [: <. %
>>>
>>> Those two tacit lines seem hard to translate for me. Instead I find the
>>> expressions below are quite easy to follow.
>>>
>>> cr=: 13 :'(x= +/ |:(y#x)#:i.x^y) #"2 (y#x)#:i.x^y'
>>> divy=: 13 :'(,.<"1((<.x%y),y)$''*''),<(x-y*<.x%y)$''*'''
>>>
>>> In most cases, with examples there is little documentation that is
>>> necessary.
>>>
>>> 2 cr 5
>>> 0 0 0 1 1
>>> 0 0 1 0 1
>>> 0 0 1 1 0
>>> 0 1 0 0 1
>>> 0 1 0 1 0
>>> 0 1 1 0 0
>>> 1 0 0 0 1
>>> 1 0 0 1 0
>>> 1 0 1 0 0
>>> 1 1 0 0 0
>>> 18 divy 5
>>> ------┐
>>> │*****│
>>> +-----+
>>> │*****│
>>> +-----+
>>> │*****│
>>> +-----+
>>> │*** │
>>> L------
>>> Maybe it is just that the explicit code looks like mathematics. It might be
>>> interesting and useful to hear how programmers and J users read code most
>>> easily.
>>>
>>> Linda
>>> -----Original Message-----
>>> From: [email protected]
>>> [mailto:[email protected]] On Behalf Of Don Kelly
>>> Sent: Friday, November 27, 2015 10:37 PM
>>> To: [email protected]
>>> Subject: Re: [Jprogramming] dyadic J
>>>
>>> there is nothing wrong with saying something like plus =: + conjugate =:+
>>> and knowing that plus is intended to be monadic (although +(real
>>> number) is the real number in either case. If you want one to work as
>>> monadic onlyand the other as dyadic only-then you have to dress them up a
>>> bit with some test and error message.
>>> you can do mean=: sum divideby count in any language.
>>> J has 2 meanings for + -which are dependent on the context. English also
>>> is
>>> like that in that some words have two unrelated meanings (e.g bow , can,
>>> twig, butt ) as well as having some with related meanings (e.g rise, level)
>>> and a lot of other things that depend on context It would be possible to
>>> build up a long list of names so that all uses of the primitives have
>>> different names and do just what the names indicate but is that of any more
>>> than limited use?
>>>
>>>
>>>
>>> On 11/27/2015 1:08 PM, 'Pascal Jasmin' via Programming wrote:
>>> > Are you saying that if I define
>>> >
>>> > floor =: (<. : (<.@]))"0 _ 0
>>> >
>>> > that it does not have integrated rank support?
>>> >
>>> > The criticism about english and documentation seems hollow to me. I
>>> don't
>>> say that Nuvoc is useless because it hasn't been implemented in 150
>>> languages. An ability to read the dictionary in English is essential to
>>> learn J, and code typically uses english shaddows from profile.ijs. Making
>>> foreign language cover verbs including autotranslating the english ones is
>>> straightforward, and answers that part of the criticism. Using the exact
>>> names from the dictionary (what I'm refering to as autodocumentation
>>> because
>>> the exact same place you would look up i. is where iota will be explained.)
>>> seems like an elegant way to ease a shallow learning curve on the process.
>>> >
>>> > The entire criticism could be applied to "you should never assign a verb
>>> to any name"
>>> >
>>> >
>>> >
>>> >
>>> > ----- Original Message -----
>>> > From: Raul Miller <[email protected]>
>>> > To: Programming forum <[email protected]>
>>> > Sent: Friday, November 27, 2015 3:27 PM
>>> > Subject: Re: [Jprogramming] dyadic J
>>> >
>>> > On Thu, Nov 26, 2015 at 4:12 PM, 'Pascal Jasmin' via Programming
>>> > <[email protected]> wrote:
>>> >> The only disadvantage I recognize is the point about special code.
>>> > It would be interesting to go over the reasons you do not recognize
>>> > the other disadvantages.
>>> >
>>> >> As to your other points, because the primitives are tacit, I believe
>>> there is integrated rank support.
>>> >>
>>> >> floor b. 0
>>> >> 0 _ _
>>> > You might want to read
>>> > http://www.jsoftware.com/pipermail/general/1998-October/000041.html
>>> >
>>> > All verbs have rank support, even verbs which contain explicit
>>> > definitions. However, for some combinations of primitives, the
>>> > interpreter takes special steps - bypassing the default implementation
>>> > of rank support with something more efficient.
>>> >
>>> >> English is needed to read dictionary, and all of the primitives are the
>>> monad dictionary entries, so everything is autodocumented.
>>> > In my experience, documentation is difficult and autodocumentation
>>> > quickly falls victim to entropy. It sounds great, but most examples I
>>> > have seen become incredibly useless in practice. It's possible to work
>>> > around this with manual effort, but the effort involved often seems to
>>> > be greater than the effort of simply doing it manually in the first
>>> > place. Where automation shines is replicating the useful manual
>>> > efforts.
>>> >
>>> >> The advantage bigger than the one you mentioned is better seeing the
>>> intent of code.
>>> > Agreed.
>>> >
>>> > Thanks,
>>> >
>>>
>>> ----------------------------------------------------------------------
>>> For information about J forums see http://www.jsoftware.com/forums.htm
>
>
>
>>
>>
>>
>>>
>>> ----------------------------------------------------------------------
>>> For information about J forums see http://www.jsoftware.com/forums.htm
>>>
>> ----------------------------------------------------------------------
>> For information about J forums see http://www.jsoftware.com/forums.htm
>> ----------------------------------------------------------------------
>> For information about J forums see http://www.jsoftware.com/forums.htm
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
