IndexedMerkleMap
function IndexedMerkleMap(height: number): typeof IndexedMerkleMapBase
Class factory for an Indexed Merkle Map with a given height.
class MerkleMap extends IndexedMerkleMap(33) {}
let map = new MerkleMap();
map.insert(2n, 14n);
map.insert(1n, 13n);
let x = map.get(2n); // 14
Indexed Merkle maps can be used directly in provable code:
ZkProgram({
methods: {
test: {
privateInputs: [MerkleMap.provable, Field],
method(map: MerkleMap, key: Field) {
// get the value associated with `key`
let value = map.getOption(key).orElse(0n);
// increment the value by 1
map.set(key, value.add(1));
}
}
}
})
Initially, every IndexedMerkleMap
is populated by a single key-value pair: (0, 0)
. The value for key 0
can be updated like any other.
When keys and values are hash outputs, (0, 0)
can serve as a convenient way to represent a dummy update to the tree, since 0 is not
effciently computable as a hash image, and this update doesn't affect the Merkle root.
Parameters
• height: number
Returns
typeof IndexedMerkleMapBase