John, notice subtle difference in what you typed:
k=:((+/),%,# (this is a train of 5 verbs, as ‘,’ is also a verb used twice
in this verb train, so you are catenating the result of the 3 verbs (+/) then
% then #, so the result is a 3 item list.
as opposed to the real fork for average below, which returns an atom.
a=:(+/)%#
k 5
5 0.2 1
a 5
5
So your (1{k) 5 is actually a new function indexing into item 1 of the result
of k as Raul described below… (it is not indexing to the % and applying that to
5 which you may have thought)...
whereas (1{a) 5 returns index error (since a returns an atom).
Hope this is clear now, Regards Rob
> On 15 Apr 2015, at 5:57 pm, Raul Miller <[email protected]> wrote:
>
> Technically, you are not indexing the tines of the fork but you are
> indexing the result of the fork.
>
> Thanks,
>
> --
> Raul
>
>
> On Wed, Apr 15, 2015 at 3:09 AM, Jon Hough <[email protected]> wrote:
>> Yes, thanks. It seems more clear. I wasn't aware you could index tines of a
>> fork.e.g.
>>
>> k =: ((+/),%,#)
>>
>>
>> (1{k) 5
>> gives 0.2
>> That was the main cause of confusion. Thanks.
>>
>>> From: [email protected]
>>> Date: Wed, 15 Apr 2015 02:55:14 -0400
>>> To: [email protected]
>>> Subject: Re: [Jprogramming] Verb to string and Verb array
>>>
>>> k is a single verb which produces 3 values for each element of its argument.
>>>
>>> It is also a fork, and each tine of the fork has a leaf which is a
>>> bond (n&v). So if you give it a left argument, that becomes a repeat
>>> count for those operations.
>>>
>>> There are some other properties which you can observe by inspection
>>> (each tine of the fork is composed of rank zero verbs, for example).
>>>
>>> Does that help?
>>>
>>> Thanks,
>>>
>>> --
>>> Raul
>>>
>>> On Wed, Apr 15, 2015 at 2:34 AM, Jon Hough <[email protected]> wrote:
>>>> I am slightly confused with how the tie (gerund) and or the linear
>>>> representation are related to this:
>>>>
>>>> k =: (^@:(3&*)) d. 1 2 3
>>>>
>>>>
>>>> results in :
>>>>
>>>>
>>>>
>>>>
>>>> ((3"0 * ^@(3&*)) , (9"0 * ^@(3&*)) , 27"0 * ^@(3&*))"0
>>>>
>>>>
>>>> Which seems to be three verbs; If I do :
>>>> k 3
>>>>
>>>>
>>>> I get :
>>>>
>>>>
>>>> 24309.3 72927.8 218783
>>>> And I can also do:
>>>>
>>>>
>>>> (0{k) 3
>>>>
>>>>
>>>> 24309.3
>>>>
>>>>
>>>>
>>>>
>>>> So whatever k is, it returns three nouns for one input noun, and it is
>>>> indexable so is an array of some sort. But what exactly (in terms of
>>>> parts-of-speech) is k?
>>>>
>>>>
>>>>
>>>>> Date: Tue, 14 Apr 2015 18:59:52 +0200
>>>>> From: [email protected]
>>>>> To: [email protected]
>>>>> Subject: Re: [Jprogramming] Verb to string and Verb array
>>>>>
>>>>> Exactly. Actually, any time you want something to work as if it were
>>>>> assigned to a name, you'd need brackets.
>>>>> Eg: *: +&. won't work, while *: (+&.) will. But this might be out of your
>>>>> scope, since +&. is an adverb, not a verb.
>>>>>
>>>>> 2015-04-14 17:35 GMT+02:00 Jon Hough <[email protected]>:
>>>>>
>>>>>> Thanks,
>>>>>> Just to be clear, '(',')',~ is just to bracketify the verb so its fork
>>>>>> (in this case) works, right?
>>>>>>
>>>>>> --- Original Message ---
>>>>>>
>>>>>> From: "Jan-Pieter Jacobs" <[email protected]>
>>>>>> Sent: April 14, 2015 5:26 PM
>>>>>> To: [email protected]
>>>>>> Subject: Re: [Jprogramming] Verb to string and Verb array
>>>>>>
>>>>>> Hey John,
>>>>>>
>>>>>> I think 1. you can do using 5!:5:
>>>>>>
>>>>>> mean =: +/%#
>>>>>> mean i.5
>>>>>> 2
>>>>>> 5!:5 <'mean'
>>>>>> +/ % #
>>>>>> datatype 5!:5 <'mean'
>>>>>> literal
>>>>>> ". (('(',')',~5!:5) <'mean'),'0 1 2 3 4'
>>>>>> 2
>>>>>> stringify =: '(',')',~5!:5
>>>>>> (stringify <'mean') , '0 1 2 3 4'
>>>>>> (+/ % #)0 1 2 3 4
>>>>>>
>>>>>> For point 2, you can use gerunds to pass around verbs in a list:
>>>>>>
>>>>>> ger =: +`-`*`%
>>>>>> ger
>>>>>> ┌─┬─┬─┬─┐
>>>>>> │+│-│*│%│
>>>>>> └─┴─┴─┴─┘
>>>>>> 10 ((1{ger) `: 0) 20
>>>>>> _10
>>>>>>
>>>>>> There's a massive amount of uses for gerunds, like / , ^: , } , and so
>>>>>> on...
>>>>>>
>>>>>> If you'd want to do these things (make a noun (or list there of)) out of
>>>>>> any type of word, I think you should be looking at atomic representation.
>>>>>>
>>>>>> Jan-Pieter
>>>>>>
>>>>>> 2015-04-14 10:11 GMT+02:00 Jon Hough <[email protected]>:
>>>>>>
>>>>>>> I have a couple of questions:
>>>>>>> 1. Is it possible to convert a verb, e.g. +/%# , to a string?": '+/%# 2
>>>>>> 3
>>>>>>> 4' executes a stringed verb with an argument. But how would I convert a
>>>>>>> verb to a string in the first place?
>>>>>>> Also, I discovered the eval verb
>>>>>>>
>>>>>>>
>>>>>>> eval=: 1 : 0
>>>>>>>
>>>>>>> ". 'w =. ' , u
>>>>>>>
>>>>>>> (ar < 'w') ab
>>>>>>>
>>>>>>> )
>>>>>>>
>>>>>>>
>>>>>>> Does this have an inverse?
>>>>>>>
>>>>>>> 2. If I have two verbs (or conjunctions, adverbs for that matter), can I
>>>>>>> not pass them around in a list?
>>>>>>> e.g. in other languages, like C# I can put functions into a list
>>>>>>> (List<Action> for example).
>>>>>>> I searched JforC and the J website and couldn't find any way to do this.
>>>>>>> Thanks Jon
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