module Fn_error:sig
..end
typexquery_error_msg =
Physical_value.item * Physical_value.item option * Physical_value.item list
exception Xquery_error of xquery_error_msg
val raise_error : Processing_context.processing_context -> Physical_value.item list -> 'a
val downgrade_error : Processing_context.processing_context -> xquery_error_msg -> 'a