/**
* Private constructor used after parsing is done.
*
* @param originalKey for reference
* @param upLevel How far up the tree to go
* @param subPath Where to go down the tree
*/
private TransposePathElement(String originalKey, int upLevel, String subPath) {
super(originalKey);
this.upLevel = upLevel;
if (StringTools.isEmpty(subPath)) {
this.subPathReader = null;
canonicalForm = "@(" + upLevel + ",)";
} else {
subPathReader = new TransposeReader(subPath);
canonicalForm = "@(" + upLevel + "," + subPathReader.getCanonicalForm() + ")";
}
}
/**
* This method is used when the TransposePathElement is used on the LFH as data.
*
* <p>Aka, normal "evaluate" returns either a Number or a String.
*
* @param walkedPath WalkedPath to evaluate against
* @return The data specified by this TransposePathElement.
*/
public Optional<Object> objectEvaluate(WalkedPath walkedPath) {
// Grap the data we need from however far up the tree we are supposed to go
PathStep pathStep = walkedPath.elementFromEnd(upLevel);
if (pathStep == null) {
return Optional.empty();
}
Object treeRef = pathStep.getTreeRef();
// Now walk down from that level using the subPathReader
if (subPathReader == null) {
return Optional.of(treeRef);
} else {
return subPathReader.read(treeRef, walkedPath);
}
}