[xquery-talk] position() and last()

[R. Mark Volkmann]

I know how to use these functions in XSLT, but I haven't figured out how to
use them in XQuery.
For example, suppose I want to put a comma between items, but not after the
last one.
I could do something like this.

for $i in $items
return (
  $i,
  if (position() = last()) then () else ","
)

This doesn't work. What am I doing wrong?