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<@}.;.n Improved

initial writing: 2000-00-00
last updated: 2004-10-26


The interpreter now “recognizes” (implements by special code) the following verbs, improving their performance in time and space:

   <@ }.;.1    <@ }.;._1    <@ }.;.2    <@ }.;._2
   <@:}.;.1    <@:}.;._1    <@:}.;.2    <@:}.;._2
   <& }.;.1    <& }.;._1    <& }.;.2    <& }.;._2
   <&:}.;.1    <&:}.;._1    <&:}.;.2    <&:}.;._2

   <@ }:;.1    <@ }:;._1    <@ }:;.2    <@ }:;._2
   <@:}:;.1    <@:}:;._1    <@:}:;.2    <@:}:;._2
   <& }:;.1    <& }:;._1    <& }:;.2    <& }:;._2
   <&:}:;.1    <&:}:;._1    <&:}:;.2    <&:}:;._2

Time and space comparisons are as follows:

   t=: 2e6$'abc'
   i=: 2e4 ?. #t
   t=: (13{a.) i}t
   t=: (10{a.) (1+i)}t
   t=: t,13 10{a.
   ts=: 6!:2 , 7!:2@]
   
   (<@}.;._2 t) -: }.&.><;._2 t
1
   (<@}:;._2 t) -: }:&.><;._2 t
1

   b=: 1=?.(#t)#40
   (b <@}.;._1 t) -: }.&.>b <;._1 t
1
   (b <@}:;._1 t) -: }:&.>b <;._1 t
1
Expression                              J 4.05                                        J 4.04
<@}.;._2 t 0.0724894 4.30400e6 0.288907 1.01631e7
<@}:;._2 t 0.0721265 4.30400e6 0.259156 1.01631e7
}.&.><;._2 t 0.206663  1.13593e7 0.224922 1.14433e7
}:&.><;._2 t 0.176644  9.99731e6 0.183163 1.00598e7
 
b <@}.;._1 t 0.13008   6.35789e6 0.626048 1.65999e7
b <@}:;._1 t 0.130454  6.35789e6 0.560835 2.34714e7
}.&.>b <;._1 t 0.432934  1.95901e7 0.45713  2.30083e7
}:&.>b <;._1 t 0.364633  1.61851e7 0.369266 1.63429e7




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