@Override
public final Expr compile(final QueryContext qc, final VarScope scp) throws QueryException {
if (root != null) root = root.compile(qc, scp);
// no steps
if (steps.length == 0) return root == null ? new Context(info) : root;
final Value init = qc.value, cv = initial(qc);
final boolean doc = cv != null && cv.type == NodeType.DOC;
qc.value = cv;
try {
final int sl = steps.length;
for (int s = 0; s < sl; s++) {
Expr e = steps[s];
// axis step: if input is a document, its type is temporarily generalized
final boolean as = e instanceof Step;
if (as && s == 0 && doc) cv.type = NodeType.NOD;
e = e.compile(qc, scp);
if (e.isEmpty()) return optPre(qc);
steps[s] = e;
// no axis step: invalidate context value
if (!as) qc.value = null;
}
} finally {
if (doc) cv.type = NodeType.DOC;
qc.value = init;
}
// optimize path
return optimize(qc, scp);
}
@SuppressWarnings({"HardCodedStringLiteral"})
public static boolean isCharOrIntegerArray(Value value) {
if (value == null) return false;
if (myCharOrIntegers == null) {
myCharOrIntegers = new HashSet<String>();
myCharOrIntegers.add("C");
myCharOrIntegers.add("B");
myCharOrIntegers.add("S");
myCharOrIntegers.add("I");
myCharOrIntegers.add("J");
}
String signature = value.type().signature();
int i;
for (i = 0; signature.charAt(i) == '['; i++) ;
if (i == 0) return false;
signature = signature.substring(i, signature.length());
return myCharOrIntegers.contains(signature);
}