It can be useful for testing equivalency
(({.;}.) -: split) 'abcd'
1
(({.;}.) -: split) (1 2 3 4)
1
(({.;}.) -: split) (i. 2 3 4)
1
Which made me wonder, why is split defined as with ,&< instead of the
simpler ; -- or so it seems?
@Raul - the intersect example was quite interesting to me. I would
naturally think of an intersection as match all A in B
Something like:
intersect2=:(i. (< #) [)~ # [
A=:1 2 3 4 5
B=:4 5 6 7 8 9
A (intersect2 -: intersect) B
1
B (intersect2 -: intersect) A
1
intersect=: [ -. -.
Is a bit of a logic problem. Let C be A that's not in B. A that is not C is
equal to A in B. That logic path would not have crossed my mind
A=:(1 2 3 4)
B=:(3 4 5 6)
C=:A-.B
]A-.C
3 4
A ([ -. -.) B
3 4
On Wed, Jul 16, 2014 at 6:29 PM, Raul Miller <[email protected]> wrote:
> Do you care what the trains are used for?
>
> One of the classic trains is set intersection:
>
> intersect=: [ -. -.
>
> Thanks,
>
> --
> Raul
>
>
> On Wed, Jul 16, 2014 at 4:26 PM, 'Dan Baronet' via Programming
> <[email protected]> wrote:
> > I am looking for good examples of use of trains.
> > Apart from the classic +/ % #, I can't think of many more.
> > Anyone with some examples? They can be of any length.
> > /Dan
> > ----------------------------------------------------------------------
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