RelBuilder API issue using table aliases in join condition

[Jess Balint]

Hi,

Using the RelBuilder API, I would like to create a join condition using
table aliases. The RelBuilder.field(relationAlias, fieldName) method only
checks the top of the stack. The top of the stack is not yet a join node if
using the RelBuilder.join(joinType, joinCondition) method. Here's an
example:

rb.scan("EMP").as("t0").scan("DEPT").as("t1")
  .join(JoinRelType.LEFT, rb.field("t0", "emp_dept_no"),
rb.field("t1", "dept_dept_no"));


I'm getting an error "java.lang.IllegalArgumentException: no relation wtih
alias 't0'; aliases are: [t1]". Would it make sense for the RelBuilder to
check the entire stack in anticipation that it's contents will be used?

Thx.
Jess