public Object pivot(
FormInstance model, EvaluationContext evalContext, List<Object> pivots, Object sentinal)
throws UnpivotableExpressionException {
// Pivot both args
Object aval = a.pivot(model, evalContext, pivots, sentinal);
Object bval = b.pivot(model, evalContext, pivots, sentinal);
// If either is the sentinal, we don't have a good way to represent the resulting expression, so
// fail
if (aval == sentinal || bval == sentinal) {
throw new UnpivotableExpressionException();
}
// If either has added a pivot, this expression can't produce any more pivots, so signal that
if (aval == null || bval == null) {
return null;
}
// Otherwise, return the value
return this.eval(model, evalContext);
}
public Vector<Object> pivot(FormInstance model, EvaluationContext evalContext)
throws UnpivotableExpressionException {
return expr.pivot(model, evalContext);
}
