@Override
public ParseTree visitChildInternal(RelNode child, int ordinal) {
final Convention convention = child.getConvention();
if (!(child instanceof JavaRel)) {
throw Util.newInternal(
"Relational expression '"
+ child
+ "' has '"
+ convention
+ "' calling convention, so must implement interface "
+ JavaRel.class);
}
JavaRel javaRel = (JavaRel) child;
final ParseTree p = javaRel.implement(this);
if ((convention == CallingConvention.JAVA) && (p != null)) {
throw Util.newInternal(
"Relational expression '"
+ child
+ "' returned '"
+ p
+ " on implement, but should have "
+ "returned null, because it has JAVA calling-convention. "
+ "(Note that similar calling-conventions, such as "
+ "Iterator, must return a value.)");
}
return p;
}
private void bindDeferred(JavaFrame frame, final RelNode rel) {
final StatementList statementList = getStatementList();
if (frame.bind == null) {
// this relational expression has not bound itself, so we presume
// that we can call its implementSelf() method
if (!(rel instanceof JavaSelfRel)) {
throw Util.newInternal(
"In order to bind-deferred, a "
+ "relational expression must implement JavaSelfRel: "
+ rel);
}
final JavaSelfRel selfRel = (JavaSelfRel) rel;
LazyBind lazyBind =
new LazyBind(
newVariable(),
statementList,
getTypeFactory(),
rel.getRowType(),
new VariableInitializerThunk() {
public VariableInitializer getInitializer() {
return selfRel.implementSelf(JavaRelImplementor.this);
}
});
bind(rel, lazyBind);
} else if ((frame.bind instanceof LazyBind)
&& (((LazyBind) frame.bind).statementList != statementList)) {
// Frame is already bound, but to a variable declared in a different
// scope. Re-bind it.
final LazyBind lazyBind = (LazyBind) frame.bind;
lazyBind.statementList = statementList;
lazyBind.bound = false;
}
}
private static int find(StatementList list, Statement statement) {
if (statement == null) {
return 0;
} else {
for (int i = 0, n = list.size(); i < n; i++) {
if (list.get(i) == statement) {
return i + 1;
}
}
throw Util.newInternal("could not find statement " + statement + " in list " + list);
}
}