Terrence Brannon wrote:
but (0 $ 2) produces an empty list. So using our understanding of what x
$ y
does (the shape of this result is x concatenated with the shape of an item
of y .) , we can see that we cannot concatenate x in this case because
it is
not a shape but an empty list.
left rank of $ is 1 so that the scalar 0 in (0 $ 2) will be extended into ,0
(rank-1) by J before execution.
You can find the rank of verb from DoJ at the top of page for any primitive, eg
Shape Of $ _ 1 _ Shape
here rank of monad $ is _ (unbound), dyad $ has left and right rank of 1 and _
respectively.
and for any verb whether primitive or user-defined, its rank can be found by b. 0
eg,
$ b. 0
_ 1 _
+ b. 0
0 0 0
/: b. 0
_ _ _
--
regards,
bill
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