First, I don't think it's necessary to allow
a variable (or variables) to be anywhere other
than the front of a chain.

  @var = [var|code] >> code >> code;

Second, it would be nice to allow a pipeline
element to pass the LHS, and invoke the RHS,
in one of two ways: iterated or not. If this
were to be done implicitly, perl (and humans)
would have to parse the whole pipeline from
the right to left, defeating the point of a
l2r pipeline syntax in the first place. So,
iteration would need to be invoked explicitly.
Perhaps something like:

  @var = for @source >> /foo/ >> sort;

--
ralph