Adverse | u :: v _ _ _ |
The result of u :: v is that of u,
provided that u completes without error; otherwise
the result is the result of v .
|
p=: 3 1 0 2 A permutation vector x=: 'ABCD' p{x DBAC ]i=: A. p Atomic index in ordered list of permutations 20 i A. x Permutation by atomic representation DBAC q=: 3 1 1 0 Not a permutation q{x DBBA A. q |index error | A.q A=: A. :: (!@#) Give index outside range in case of error A p 20 A q 24 24 A. x |index error | 24 A.x