ButtonwoodLibrary

Functions

sortTokens

Returns sorted token addresses, used to handle return values from pairs sorted in this order

function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1);

Parameters

Name	Type	Description
tokenA	address	First token address
tokenB	address	Second token address

Returns

Name	Type	Description
token0	address	First sorted token address
token1	address	Second sorted token address

pairFor

Predicts the address that the Pair contract for given tokens would have been deployed to

Specifically, this calculates the CREATE2 address for a Pair contract.

It's done this way to avoid making any external calls, and thus saving on gas versus other approaches.

function pairFor(address factory, address tokenA, address tokenB) internal pure returns (address pair);

Parameters

Name	Type	Description
factory	address	The address of the ButtonswapFactory used to create the pair
tokenA	address	First token address
tokenB	address	Second token address

Returns

Name	Type	Description
pair	address	The pair address

getPools

Fetches and sorts the pools for a pair. Pools are the current token balances in the pair contract serving as liquidity.

function getPools(address factory, address tokenA, address tokenB)
    internal
    view
    returns (uint256 poolA, uint256 poolB);

Parameters

Name	Type	Description
factory	address	The address of the ButtonswapFactory
tokenA	address	First token address
tokenB	address	Second token address

Returns

Name	Type	Description
poolA	uint256	Pool corresponding to tokenA
poolB	uint256	Pool corresponding to tokenB

getReservoirs

Fetches and sorts the reservoirs for a pair. Reservoirs are the current token balances in the pair contract not actively serving as liquidity.

function getReservoirs(address factory, address tokenA, address tokenB)
    internal
    view
    returns (uint256 reservoirA, uint256 reservoirB);

Parameters

Name	Type	Description
factory	address	The address of the ButtonswapFactory
tokenA	address	First token address
tokenB	address	Second token address

Returns

Name	Type	Description
reservoirA	uint256	Reservoir corresponding to tokenA
reservoirB	uint256	Reservoir corresponding to tokenB

quote

Given some amount of an asset and pair pools, returns an equivalent amount of the other asset

function quote(uint256 amountA, uint256 poolA, uint256 poolB) internal pure returns (uint256 amountB);

Parameters

Name	Type	Description
amountA	uint256	The amount of token A
poolA	uint256	The balance of token A in the pool
poolB	uint256	The balance of token B in the pool

Returns

Name	Type	Description
amountB	uint256	The amount of token B

getAmountOut

Given an input amount of an asset and pair pools, returns the maximum output amount of the other asset Factors in the fee on the input amount.

function getAmountOut(uint256 amountIn, uint256 poolIn, uint256 poolOut) internal pure returns (uint256 amountOut);

Parameters

Name	Type	Description
amountIn	uint256	The input amount of the asset
poolIn	uint256	The balance of the input asset in the pool
poolOut	uint256	The balance of the output asset in the pool

Returns

Name	Type	Description
amountOut	uint256	The output amount of the other asset

getAmountIn

Given an output amount of an asset and pair pools, returns a required input amount of the other asset

function getAmountIn(uint256 amountOut, uint256 poolIn, uint256 poolOut) internal pure returns (uint256 amountIn);

Parameters

Name	Type	Description
amountOut	uint256	The output amount of the asset
poolIn	uint256	The balance of the input asset in the pool
poolOut	uint256	The balance of the output asset in the pool

Returns

Name	Type	Description
amountIn	uint256	The required input amount of the other asset

getAmountsOut

Given an ordered array of tokens and an input amount of the first asset, performs chained getAmountOut calculations to calculate the output amount of the final asset

function getAmountsOut(address factory, uint256 amountIn, address[] memory path)
    internal
    view
    returns (uint256[] memory amounts);

Parameters

Name	Type	Description
factory	address	The address of the ButtonswapFactory that created the pairs
amountIn	uint256	The input amount of the first asset
path	address[]	An array of token addresses [tokenA, tokenB, tokenC, ...] representing the path the input token takes to get to the output token

Returns

Name	Type	Description
amounts	uint256[]	The output amounts of each asset in the path

getAmountsIn

Given an ordered array of tokens and an output amount of the final asset, performs chained getAmountIn calculations to calculate the input amount of the first asset

function getAmountsIn(address factory, uint256 amountOut, address[] memory path)
    internal
    view
    returns (uint256[] memory amounts);

Parameters

Name	Type	Description
factory	address	The address of the ButtonswapFactory that created the pairs
amountOut	uint256	The output amount of the final asset
path	address[]	An array of token addresses [tokenA, tokenB, tokenC, ...] representing the path the input token takes to get to the output token

Returns

Name	Type	Description
amounts	uint256[]	The input amounts of each asset in the path

Errors

IdenticalAddresses

Identical addresses provided

error IdenticalAddresses();

ZeroAddress

Zero address provided

error ZeroAddress();

InsufficientAmount

Insufficient amount provided

error InsufficientAmount();

InsufficientLiquidity

Insufficient liquidity provided

error InsufficientLiquidity();

InsufficientInputAmount

Insufficient input amount provided

error InsufficientInputAmount();

InsufficientOutputAmount

Insufficient output amount provided

error InsufficientOutputAmount();

InvalidPath

Invalid path provided

error InvalidPath();