I usually do tacit programming with J,
but what I mean by this is I don’t use x or y
that is I can write tacit _verbs_ only.
I know one can be tacit on modifier level etc
but I didn’t ever learn how.
1. is there any good place to start learning?
if not, would anyone mind putting together
some material on this?
2. here is an example of something that in terms
of data manipulation is not very J-ish
but let’s assume I need to do it this way
for some reason:
onsub =: 2 : 'n&{. , n&}.@:(n&{."1) ,. u@:(n&}."1)@(n&}.)'
(
first I wrote it as an adverb without all the 'n&' parts,
then I generalized by adding them – it’s repetitive
but it does what I want it to do
)
usage is like
|. onsub 2 mat =: ? 5 6 $ 20
reversing (mirror) the 3 by 4 lower right submatrix
(a) how to write this without reference to u or n?
(b) what if I wanted to use it like this:
(|.;#) onsub 2 mat
with the result like everything happening in onsub
after application of u will work on its >@{.
and after everything is done its }. will be ;ed.
btw feel free to alter this thread’s subject, I just don’t know
what direction this will take so I picked the broad 'tacit' key
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