switch expression (and | &) switch expressionor
sink expression & sink expression
& operator is overloaded: it can be used either as a Boolean
and operator, or as a tee
operator on sinks.
When applied to
markup sink and
string sink expressions, the
& operator returns a
string sink. If all arguments are of
markup sink type, the result type will be a
sink as well. The sink returned by the operator acts as a "tee" connector: any data output into it will be
replicated and distributed to all component sinks that were given as arguments of
using output as #error & file "error.log" output "An error occurred."