LinkedList

TODO: add the possibility to work with arrays on the DSL level variable ARR_NAME -> [type: array,elementType: uint256, linkToNextEl: 0x123] (next element): [data: 0x0001, linkToNextEl: 0x124] (last element): [data: 0x0005, linkToNextEl: 0x000]

EMPTY

bytes32 EMPTY

getType

function getType(bytes32 _arrName) external view returns (bytes1)

Returns length of the array

Parameters

Name	Type	Description
_arrName	bytes32	is a bytecode of the array name

getLength

function getLength(bytes32 _arrName) external view returns (uint256)

Returns length of the array

Parameters

Name	Type	Description
_arrName	bytes32	is a bytecode of the array name

get

function get(uint256 _index, bytes32 _arrName) public view returns (bytes32 data)

Returns the item data from the array by its index

Parameters

Name	Type	Description
_index	uint256	is an index of the item in the array that starts from 0
_arrName	bytes32	is a bytecode of the array name

Return Values

Name	Type	Description
data	bytes32	is a bytecode of the item from the array or empty bytes if no item exists by this index

declare

function declare(bytes1 _type, bytes32 _arrName) external

Declares the new array in dependence of its type

Parameters

Name	Type	Description
_type	bytes1	is a bytecode type of the array. Bytecode of each type can be find in Context contract
_arrName	bytes32	is a bytecode of the array name

addItem

function addItem(bytes32 _item, bytes32 _arrName) external

Pushed item to the end of the array. Increases the length of the array

Parameters

Name	Type	Description
_item	bytes32	is a bytecode type of the array. Bytecode of each type can be find in Context contract
_arrName	bytes32	is a bytecode of the array name

getHead

function getHead(bytes32 _arrName) public view returns (bytes32)

Returns the head position of the array: - bytes32(0x0) value if array has not declared yet, - bytes32(type(uint256).max if array was just declared but it is empty - other bytecode with a position of the first element of the array

Parameters

Name	Type	Description
_arrName	bytes32	is a bytecode of the array name

_insertItem

function _insertItem(bytes32 _position, bytes32 _item) internal

Insert item in the array by provided position. Updates new storage pointer for the future inserting

_updateLinkToNextItem

function _updateLinkToNextItem(bytes32 _position, bytes32 _nextPosition) internal

Updates the next position for the provided(current) position

_getEmptyMemoryPosition

function _getEmptyMemoryPosition() internal view returns (bytes32 position)

Uses 0x40 position as free storage pointer that returns value of current free position. In this contract it 0x40 position value updates by _insertItem function anfter adding new item in the array. See: mload - free memory pointer in the doc

Return Values

Name	Type	Description
position	bytes32	is a value that stores in the 0x40 position in the storage

_getData

function _getData(bytes32 _position) internal view returns (bytes32 data, bytes32 nextPosition)

Returns the value of current position and the position(nextPosition) to the next object in array

Parameters

Name	Type	Description
_position	bytes32	is a current item position in the array

Return Values

Name	Type	Description
data	bytes32	is a current data stored in the _position
nextPosition	bytes32	is a next position to the next item in the array