Saxon

From Gunther Rademacher on saxon-help list

Recently I ran some tests with a REx parser on Saxon-EE and I noticed a

performance degradation that occurs with -opt:10, when byte code is

generated.

Tried to isolate it as much as possible, which resulted in the small

program below. The $x[$x[$i]] construct presumably causes the

degradation, something similar is used in a REx lexer's state machine.

  declare variable $n external;

  declare variable $x := 1 to $n;

  avg(for $i in $x return $x[$x[$i]])

With $n=65536, it executes in about 8 milliseconds. Unless byte code

generation is in effect, in which case it takes 8 seconds.