/**
* get a Target instance. A target consists of a reference name and an EvalNode corresponding to
* the reference name. According to evaluation state, it returns different EvalNodes. If the
* expression corresponding to the reference name is evaluated, it just returns {@link FieldEval}
* (i.e., a column reference). Otherwise, it returns the original EvalNode of the expression.
*
* @param referenceName The reference name to get EvalNode
* @param unevaluatedForm If TRUE, it always return the annotated EvalNode of the expression.
* @return
*/
public Target getTarget(String referenceName, boolean unevaluatedForm) {
String normalized = referenceName;
int refId = nameToIdMap.get(normalized);
if (!unevaluatedForm
&& evaluationStateMap.containsKey(refId)
&& evaluationStateMap.get(refId)) {
EvalNode evalNode = idToEvalMap.get(refId);
// If the expression is already evaluated, it should use the FieldEval to access a field
// value.
// But, if this reference name is not primary name, it cannot use the reference name.
// It changes the given reference name to the primary name.
if (isEvaluated(normalized) && !isPrimaryName(refId, referenceName)) {
return new Target(
new FieldEval(getPrimaryName(refId), evalNode.getValueType()), referenceName);
}
EvalNode referredEval;
if (evalNode.getType() == EvalType.CONST) {
referredEval = evalNode;
} else {
referredEval = new FieldEval(idToNamesMap.get(refId).get(0), evalNode.getValueType());
}
return new Target(referredEval, referenceName);
} else {
if (idToEvalMap.containsKey(refId)) {
return new Target(idToEvalMap.get(refId), referenceName);
} else {
return null;
}
}
}
