LazyIMTData

A struct that holds a LazyIMT data

struct LazyIMTData {
  uint40 maxIndex;
  uint40 numberOfLeaves;
  mapping(uint256 => uint256) elements;
}

InternalLazyIMT

This implementation is taken from zk-kit https://github.com/privacy-scaling-explorations/zk-kit/blob/main/packages/imt.sol/contracts/internal/InternalLazyIMT.sol and modified to work with MACI.

A LazyIMT with Zeroes value set to the hash of a MACI Blank State Leaf

MAX_DEPTH

uint256 MAX_DEPTH

SNARK_SCALAR_FIELD

uint256 SNARK_SCALAR_FIELD

MAX_INDEX

uint40 MAX_INDEX

Z_0

uint256 Z_0

Z_1

uint256 Z_1

Z_2

uint256 Z_2

Z_3

uint256 Z_3

Z_4

uint256 Z_4

Z_5

uint256 Z_5

Z_6

uint256 Z_6

Z_7

uint256 Z_7

Z_8

uint256 Z_8

Z_9

uint256 Z_9

Z_10

uint256 Z_10

Z_11

uint256 Z_11

Z_12

uint256 Z_12

Z_13

uint256 Z_13

Z_14

uint256 Z_14

Z_15

uint256 Z_15

Z_16

uint256 Z_16

Z_17

uint256 Z_17

Z_18

uint256 Z_18

Z_19

uint256 Z_19

Z_20

uint256 Z_20

Z_21

uint256 Z_21

Z_22

uint256 Z_22

Z_23

uint256 Z_23

Z_24

uint256 Z_24

Z_25

uint256 Z_25

Z_26

uint256 Z_26

Z_27

uint256 Z_27

Z_28

uint256 Z_28

Z_29

uint256 Z_29

Z_30

uint256 Z_30

Z_31

uint256 Z_31

Z_32

uint256 Z_32

_defaultZero

function _defaultZero(uint8 index) internal pure returns (uint256)

Returns the default zero value for a given index

Parameters

Name	Type	Description
index	uint8	The index of the zero value

Return Values

Name	Type	Description
[0]	uint256	The zero value

_init

function _init(struct LazyIMTData self, uint8 depth) internal

Initializes the LazyIMT

Parameters

Name	Type	Description
self	struct LazyIMTData	The LazyIMTData
depth	uint8	The depth of the tree

_indexForElement

function _indexForElement(uint8 level, uint40 index) internal pure returns (uint40)

Returns the index for a given level and index

Parameters

Name	Type	Description
level	uint8	The level
index	uint40	The index

Return Values

Name	Type	Description
[0]	uint40	The index for the element

_insert

function _insert(struct LazyIMTData self, uint256 leaf) internal

Inserts a leaf into the LazyIMT

Parameters

Name	Type	Description
self	struct LazyIMTData	The LazyIMTData
leaf	uint256	The leaf to insert

_root

function _root(struct LazyIMTData self) internal view returns (uint256)

Returns the root of the LazyIMT

Parameters

Name	Type	Description
self	struct LazyIMTData	The LazyIMTData

Return Values

Name	Type	Description
[0]	uint256	The root of the LazyIMT

_root

function _root(struct LazyIMTData self, uint8 depth) internal view returns (uint256)

Returns the root of the LazyIMT

Parameters

Name	Type	Description
self	struct LazyIMTData	The LazyIMTData
depth	uint8	The depth of the tree

Return Values

Name	Type	Description
[0]	uint256	The root of the LazyIMT

_root

function _root(struct LazyIMTData self, uint40 numberOfLeaves, uint8 depth) internal view returns (uint256)

Returns the root of the LazyIMT

Here it's assumed that the depth value is valid. If it is either 0 or > 2^8-1 this function will panic.

Parameters

Name	Type	Description
self	struct LazyIMTData	The LazyIMTData
numberOfLeaves	uint40	The number of leaves
depth	uint8	The depth of the tree

Return Values

Name	Type	Description
[0]	uint256	The root of the LazyIMT

_levels

function _levels(struct LazyIMTData self, uint40 numberOfLeaves, uint8 depth, uint256[] levels) internal view

Updates the levels of the LazyIMT

Parameters

Name	Type	Description
self	struct LazyIMTData	The LazyIMTData
numberOfLeaves	uint40	The number of leaves
depth	uint8	The depth of the tree
levels	uint256[]	The levels of the tree