Child edges are 0 bits and each node ends with a 1 bit in labelBitmap. An edge of nodeId has exactly nodeId preceding 1 bits, so its label index is bmIdx - nodeId. Child nodes follow the same order as labels, starting at 1 because node 0 is the root. Therefore, the child node ID is bmIdx - nodeId + 1.
Use this identity in Has and keys instead of countZeros. Keep rank for wildcard restoration, where the cursor lacks the parent node ID.
Existing short/long query benchmarks take ~12%/~11% less time, with no additional allocations or changes to the index layout.
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