refactor: nuke unused getSiblingPath oracle

[benesjan]

Made sense to nuke it as it was unused. getMembershipWitness oracle was used instead.

[benesjan]

• refactor: nuke unused getSiblingPath oracle #11090 👈 (View in Graphite)
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[benesjan]

Made sense to have just getMembershipWitness exposed here as that's what the consumers of the API really wanted.

[AztecBot]

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[nventuro]

I'm confused by this - it seems this oracle is only called in the following way:

pub unconstrained fn get_membership_witness<let N: u32, let M: u32>(
    block_number: u32,
    tree_id: Field,
    leaf_value: Field,
) -> MembershipWitness<N, M> {
    let fields: [Field; M] = get_membership_witness_oracle(block_number, tree_id, leaf_value);
    MembershipWitness { index: fields[0], path: array::subarray(fields, 1) }
}

If we discard the leaf anyway, shouldn't we delete getMemberShipWitness and replace it for getSiblingPath instead? What's the purpose of the leaf index?

[benesjan]

If we discard the leaf anyway, shouldn't we delete getMemberShipWitness and replace it for getSiblingPath instead? What's the purpose of the leaf index?

@nventuro The leaf index is used to figure out from which side to start hashing the sibling path and it's used for example here.

Where did you see that the index get discarded? I could not find a callsite of the oracle where that happens.

[nventuro]

You're right, I misread the very snippet I pasted 🤦