The dyads ;@:{ and [: ; { are now supported by special code. The following benchmarks demonstrate the improvement.

   x=: ;:'fourscore and ten years ago our fathers brought forth on this continent'
   i=: ?1e6$#x
   (;i{x) -: i ;@:{ x
1
   ts=: 6!:2 , 7!:2@]

   ts ';i{x'
0.286051 1.67779e7
   ts 'i ;@:{ x'
0.107211 8.38944e6