[Jprogramming] Tacit vs. Explicit
Björn Helgason
gosinn at gmail.com
Fri Oct 7 21:35:17 HKT 2011
paren is also a very nice option in the trace utility and my assist in
understanding tacit verbs
paren '(+/ % #) 90 90 90'
(((+ /) % #) 90 90 90)
and then trace too
trace '(+/ % #) 90 90 90'
--------------- 3 Adverb -----
+
/
+/
--------------- 5 Trident ----
+/
%
#
+/ % #
--------------- 8 Paren ------
(
+/ % #
)
+/ % #
--------------- 0 Monad ------
+/ % #
90 90 90
90
==============================
90
2011/10/7 Björn Helgason <gosinn at gmail.com>
> I can think of many reasons to go from tacit to explicit and one of the
> biggest is understanding the tacit expression better.
>
> It is relatively easy to create tacit from explicit and understand what is
> happening.
>
> Going the other way around is a major hurdle for people starting out using
> J and explaining one short tacit line may need a whole page of text.
>
> Being able to go from tacit to explicit and for example explaining the
> trace of the expression could be a good start and I think this kind of work
> is very important and well worth doing.
>
> I guess that people are often too embarrassed to ask what an tacit
> expression is really doing and why/how it works
>
>
> 2011/10/7 Bo Jacoby <bojacoby at yahoo.dk>
>
>>
>>
>> Why, Linda, do you ever want to go from the tacit expression to an
>> explicit expression?
>>
>> a =: ((+/ % #) * 1 + #) - +/
>> a 90 90 90
>> 90
>> NB. ((+/ % #) * (1 + #)) === (((+/ % #) * 1) + ((+/ % #) * #)) === ((+/ %
>> #) + ((+/))
>> a =: +/ % #
>> a 90 90 90
>> 90
>>
>>
>>
>>
>>
>> >________________________________
>> >Fra: Björn Helgason <gosinn at gmail.com>
>> >Til: Programming forum <programming at jsoftware.com>
>> >Sendt: 13:16 fredag den 7. oktober 2011
>> >Emne: Re: [Jprogramming] Tacit vs. Explicit
>> >
>> >Is this what you are looking for?
>> >
>> > load'c:\j701\addons\general\misc\trace.ijs'
>> > trace'(((+/ % #) * 1 + #) - +/)90 90 90'
>> >
>> >
>> >2011/10/7 Linda Alvord <lindaalvord at verizon.net>
>> >
>> >> Is there a way to go from a tacit expression to find the correct
>> explicit
>> >> expression?
>> >>
>> >> a =: 13 :'((+/ % #) * 1 + #) - +/'
>> >> a 90 90 90
>> >> |syntax error: a
>> >> | a 90 90 90
>> >>
>> >> b=:((+/ % #) * 1 + #) - +/
>> >> b 90 90 90
>> >> 90
>> >>
>> >> c =: 13 :'((+/ % #) * 1 + #) - +/y'
>> >> c 90 90 90
>> >> _540
>> >>
>> >> d =: 13 :'((+/ % #) * 1 + #y) - +/y'
>> >> d 90 90 90
>> >> _269
>> >>
>> >> e=: 13 :'((+/ % #y) * 1 + #y) - +/y'
>> >> e 90 90 90
>> >> _268.667
>> >>
>> >>
>> >> a
>> >> 3 : '((+/ % #) * 1 + #) - +/'
>> >> b
>> >> ((+/ % #) * 1 + #) - +/
>> >> c
>> >> [: ((+/ % #) * 1 + #) [: - +/
>> >> d
>> >> ([: (+/ % #) [: * 1 + #) - +/
>> >> e
>> >> (([: +/ [: % #) * 1 + #) - +/
>> >>
>> >>
>> >>
>> >> 5!:4 <'a'
>> >>
>> >> -- 3
>> >> -- : -+- ,:'((+/ % #) * 1 + #) - +/'
>> >>
>> >>
>> >> 5!:4 <'b'
>> >>
>> >> -- / --- +
>> >> ----+- %
>> >> │ L- #
>> >> ------+- *
>> >> │ │ -- 1
>> >> │ L---+- +
>> >> --+ L- #
>> >> +- -
>> >> L- / --- +
>> >>
>> >>
>> >> 5!:4 <'c'
>> >>
>> >> -- [:
>> >> │ -- / --- +
>> >> │ ------+- %
>> >> │ │ L- #
>> >> +----+- *
>> >> --+ │ -- 1
>> >> │ L-----+- +
>> >> │ L- #
>> >> │ -- [:
>> >> L----+- -
>> >> L- / --- +
>> >>
>> >>
>> >> 5!:4 <'d'
>> >>
>> >> -- [:
>> >> │ -- / --- +
>> >> +----+- %
>> >> │ L- #
>> >> ------+
>> >> │ │ -- [:
>> >> │ │ +- *
>> >> │ L----+ -- 1
>> >> --+ L-----+- +
>> >> │ L- #
>> >> +- -
>> >> L- / --- +
>> >>
>> >>
>> >>
>> >>
>> >>
>> >> 5!:4 <'e'
>> >>
>> >> -- [:
>> >> +- / --- +
>> >> ----+
>> >> │ │ -- [:
>> >> │ L-----+- %
>> >> ------+ L- #
>> >> │ +- *
>> >> │ │ -- 1
>> >> --+ L---+- +
>> >> │ L- #
>> >> +- -
>> >> L- / --- +
>> >>
>> >> Do you get the answer you want with b, c, d or e? I would have guessed
>> it
>> >> should be b , that doesn't seem to be very helpful.
>> >>
>> >> -----Original Message-----
>> >> From: programming-bounces at jsoftware.com
>> >> [mailto:programming-bounces at jsoftware.com] On Behalf Of Henry Rich
>> >> Sent: Wednesday, October 05, 2011 5:25 AM
>> >> To: Programming forum
>> >> Subject: Re: [Jprogramming] Tacit vs. Explicit
>> >>
>> >> bestfit=:(],0{&<.&<.0.5+(1+0.01*_15+(?@(30"_)))*(((+/ % #)*1+#)-(+/)))
>> >> bestfit 90 90 90
>> >> 90 90 90 101
>> >> bestfit 90 90 90
>> >> 90 90 90 102
>> >> bestfit 90 90 90
>> >> 90 90 90 103
>> >> bestfit 90 90 90
>> >> 90 90 90 78
>> >>
>> >> Henry Rich
>> >>
>> >> On 10/5/2011 5:19 AM, Gian Medri wrote:
>> >> > Hi!
>> >> > I have a function:
>> >> > bestfit=:(],0{&<.&<.0.5+(1+0.01*(?30)-15)*(((+/ % #)*1+#)-(+/)))
>> >> > that calculates the n+1 element.
>> >> > bestfit 90 90 90
>> >> > 90 90 90 81
>> >> > The tacit form doesn't work properly, because the "?" is not active
>> every
>> >> > time I call bestfit 90 90 90.
>> >> > When I use
>> >> > (],0{&<.&<.0.5+(1+0.01*(?50)-25)*(((+/ % #)*1+#)-(+/))) 90 90 90
>> >> > then the function works properly.
>> >> >
>> >> > My question is if it is possible to have a tacit verb with the "?"
>> >> active.
>> >> >
>> >> > Thanks
>> >> >
>> >> > Gian Medri
>> >> >
>> ----------------------------------------------------------------------
>> >> > 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
>> >>
>> >
>> >
>> >
>> >--
>> >Björn Helgason, Verkfræðingur
>> >Fornustekkum II
>> >781 Hornafirði,
>> >t-póst: gosinn at gmail.com
>> >gsm: +3546985532
>> >twitter: @flugfiskur
>> >http://groups.google.com/group/J-Programming
>> >
>> >
>> >Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans
>> >
>> >góður kennari getur stigið á tær án þess að glansinn fari af skónum
>> > /|_ .-----------------------------------.
>> > ,' .\ / | Með léttri lund verður |
>> > ,--' _,' | Dagurinn í dag |
>> > / / | Enn betri en gærdagurinn |
>> > ( -. | `-----------------------------------'
>> > | ) | (\_ _/)
>> > (`-. '--.) (='.'=) ♖♘♗♕♔♙
>> > `. )----' (")_(") ☃☠
>> >----------------------------------------------------------------------
>> >For information about J forums see http://www.jsoftware.com/forums.htm
>> >
>> >
>> ----------------------------------------------------------------------
>> For information about J forums see http://www.jsoftware.com/forums.htm
>>
>
>
>
> --
> Björn Helgason, Verkfræðingur
> Fornustekkum II
> 781 Hornafirði,
> t-póst: gosinn at gmail.com
> gsm: +3546985532
> twitter: @flugfiskur
> http://groups.google.com/group/J-Programming
>
>
> Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans
>
> góður kennari getur stigið á tær án þess að glansinn fari af skónum
> /|_ .-----------------------------------.
> ,' .\ / | Með léttri lund verður |
> ,--' _,' | Dagurinn í dag |
> / / | Enn betri en gærdagurinn |
> ( -. | `-----------------------------------'
> | ) | (\_ _/)
> (`-. '--.) (='.'=) ♖♘♗♕♔♙
> `. )----' (")_(") ☃☠
>
--
Björn Helgason, Verkfræðingur
Fornustekkum II
781 Hornafirði,
t-póst: gosinn at gmail.com
gsm: +3546985532
twitter: @flugfiskur
http://groups.google.com/group/J-Programming
Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans
góður kennari getur stigið á tær án þess að glansinn fari af skónum
/|_ .-----------------------------------.
,' .\ / | Með léttri lund verður |
,--' _,' | Dagurinn í dag |
/ / | Enn betri en gærdagurinn |
( -. | `-----------------------------------'
| ) | (\_ _/)
(`-. '--.) (='.'=) ♖♘♗♕♔♙
`. )----' (")_(") ☃☠
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