Here's a challenge:
Just because @ might show up in third grade, that doesn't include all its
little cousins like @: & and &:
To me, minimal documentation begins with the data using capital letters for
the name. Since F is not a verb, don't start here.
F=: </.~ +/\@(-.@+._1&|.)@:=&(<,'&')
Also it is a very tangled verb:
5!:4 <'F'
-- ~ --- /. ---- <
│ -- \ --- / --- +
│ │
│ │ -- -.
--+ -- @ -+ -- @ -+- +.
│ │ │ │
│ -- @: --+ L-----+ -- _1
│ │ │ L- & -+- |.
L- & -+ L- =
Begin here with the data:
L- <,'&'
]T=: ;:'4&count int 3 8&inrange'
--T-T-----T---T---T-T-------┐
│4│&│count│int│3 8│&│inrange│
L-+-+-----+---+---+-+--------
Here's the challenge. Just for fun, write a single line direct definition of
F. Use simple J. You may use @ and name the verb f.
f=: 13 :' (direcct defn) '
f T
------------T-----T---------------┐
│--T-T-----┐│----┐│----T-T-------┐│
││4│&│count│││int│││3 8│&│inrange││
│L-+-+------│L----│L---+-+--------│
L-----------+-----+----------------
Apply f to T to get the result.
That is usually enough information for sending a question to the forum.
Advanced programmers could use tacit verbs like Pascal's verb. Often you can
only explain these parts in words. Having a sample of your data and an
indication of whether you are planning one or two arguments for your verb
will help.
Linda
Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Cliff Reiter
Sent: Monday, January 26, 2015 3:46 AM
To: [email protected]
Subject: Re: [Jprogramming] A parsing challenge
Lovely. Tiny remark:
<mailto:-.@> -.@+. could be replaced by +:
On 1/26/2015 1:00 AM, Raul Miller wrote:
> A note of explanation...
>
> (I have been noticing that far too much software is poorly documented.
> And while I cannot do an adequate job of documenting other people's
> software, I can document software I write.)
>
> F=: </.~ +/\@( <mailto:-.@+._1&;|.)@:=&(%3c,'&')>
-.@+._1&|.)@:=&(<,'&')
> T=: ;:'4&count int 3 8&inrange'
>
> The first thing I do is find out where & appears:
> =&(<,'&') T
> 0 1 0 0 0 1 0
>
> The second thing I do is rotate to the right and combine:
> (+. _1&|.) =&(<,'&') T
> 0 1 1 0 0 1 1
>
> Except I want to mark the beginning of each section with a 1, and
> right now they are zeros.
> ( <mailto:-.@> -.@+. _1&|.) =&(<,'&') T
> 1 0 0 1 1 0 0
>
> As an aside, note that I could have cut that step out if I had started
> by identifying where & does not appear (and then combine using logical
> and instead of logical or):
>
> (* _1&|.) ~:&(<,'&') T
> 1 0 0 1 1 0 0
>
> Next, I use plus scan to turn my markers into keys:
>
> +/\ (* _1&|.) ~:&(<,'&') T
> 1 1 1 2 3 3 3
>
> Finally, I use these keys to group the original elements:
>
> T </.~ +/\ (* _1&|.) ~:&(<,'&') T
> +-----------+-----+---------------+
> |+-+-+-----+|+---+|+---+-+-------+|
> ||4|&|count|||int|||3 8|&|inrange||
> |+-+-+-----+|+---+|+---+-+-------+|
> +-----------+-----+---------------+
>
> And that exposition pretty much follows the thought process I
> originally used to compose the sentence.
>
> Thanks,
>
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