What an excellent example.
Regarding the question at the end.
I have more or less understood explicit using y and x as placeholders for
the arguments and statements without such specifics where the arguments
float into the stream effortlessly being tacit.
So no x nor y make it tacit I assume.
2010/11/21 Henry Rich <henryhr...@nc.rr.com>
> I think the tenor of this debate misses an important point. 'Tacit' is
> not a simple yes-or-no.
>
> Take an example. Suppose I have a filespec (like 'C:\xxx\*.txt') and I
> want a list of filenames in order of modification date, but not
> including directories.
>
> A beginner might write
>
> files =. 1!:0 filespec
> attrs =. 4 {"1 files
> notdir =. 'd' ~: 4 {"1 > attrs
> pfiles =. notdir # files
> names =. 0 {"1 pfiles
> times =. 1 {"1 pfiles
> namesinorder =. names /: times
>
> With more experience, they would see some opportunities for using tacit
> features:
>
> pfiles =. (#~ 'd' ~: (4;4)&{::"1) files
> namesinorder =. (0&{"1 /: 1&{"1) pfiles
>
> As J feels more natural, they might write
>
> namesinorder =. (0&{"1 /: 1&{"1) (#~ 'd' ~: (4;4)&{::"1) 1!:0 filespec
>
> (with appropriate comments, of course). Somewhere along the line this
> would fail on an empty directory and they would add a test for that:
>
> namesinorder =. (0&{"1 /: 1&{"1) (#~ 'd' ~: (4;4)&{::"1)^:(*...@#) 1!:0
> filespec
>
>
> If parts of that are useful enough to get their own names, they would:
> culling =: 1 : 'u#]'
> fisdir =: 'd' = (4;4)&({::)"1
> ifany =: ^:(*...@#@])
>
> and the solution would be written
>
> namesinorder =. (0&{"1 /: 1&{"1) -...@fisdir culling ifany 1!:0 filespec
>
>
> Is it tacit? Is it explicit?
>
> Henry Rich
>
>
> On 11/21/2010 2:10 PM, Dan Bron wrote:
> > Ian wrote:
> >> If reading tacit expressions posed no significant problems
> >> to anyone except dunces, then surely there would have been
> >> no need for this work and it would not have been done?
> >>
> >> So doesn't this put Bj�rn's assertion beyond debate?
> >
> > If reading Icelandic posed no significant problems to anyone except
> dunces, then surely there would be no need for this work:
> >
> > http://members.multimania.co.uk/mareka/iceland/icelandic.html
> >
> > and it would not have been done? Don't pages like that put my assertion
> beyond debate?
> >
> > It just takes practice, guys.
> >
> > -Dan
> >
> >
> >
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