Saxon » SaxonJS

After calling reverse($var), the value of $var is changed to be in reverse order.

reverse is implemented as arg[0].expand().reverse() where arg[0] is an iterator. The problem is that (a) if arg[0] is a ForArray iterator, then expand() returns the original array, and (b) the Javascript function reverse() modifies its argument in-situ.

So the code needs to ensure that the array is copied before calling reverse()@, or perhaps to avoid the @expand() operation and prepend each item returned by the iterator to a target array.

(Reported informally by John Lumley)