Hello,
Could you please explain the followin thing:
[ns=:?10#1500
1225 1362 1263 1376 1445 383 1260 397 175 1188
NB. I try to find 3digit numbers with unique digits.
I wrote this:
ns#~((((3&=@#) *. (*./@~:))@":)"0) ns
I think here are too many brackets, so I removed some
ns#~(((3&=@#*.*./@~:)@":)"0) ns
Q1: how J understand how to split (xyz) here? How can I parse it in mind?
Q2: Why I should write 3&=, but not *.&/ ?
After that I did:
(((3=#*.*./@~:)@":)"0) ns
Q3: It absolutely not clear for me, how can I write 3=# (explicit)
instead of 3&=@# (tacit)?
It is the main problem in J for me, for example I write expression:
[ns2=:i.10
0 1 2 3 4 5 6 7 8 9
ns2#~-.2|ns2 NB. it looks good, no problem.
But the problem, if I would like convert it into the function, I
should absolutely rewrite it:
ns2#~(-.@(2&|))ns2 NB. additional Q: why 2&| in brakets?
@, which is not used in normal expression, that is strange for me that
expression and function is not the same, K looks more habitually at
this point:
expression: ns2:!10; ns2@~ns2!2
function: ns2@{~x!2} ns2 / exactly the same like expression.
What is why it is not clear for me why J expression in explicit style
by default, but function in tacit.
Thank you and sorry if described problem is not very clear.
--
Regards,
Alexander.
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