Last update: September 30, 2021

HybridPool

Trident exchange pool template with hybrid like-kind formula for swapping between an ERC-20 token pair.

The reserves are stored as bento shares. However, the stableswap invariant is applied to the underlying amounts. The API uses the underlying amounts.

Functions

constructor

  function constructor(
  ) public

mint

  function mint(
  ) public returns (uint256 liquidity)

Mints LP tokens - should be called via the router after transferring bento tokens. The router must ensure that sufficient LP tokens are minted by using the return value.

burn

  function burn(
  ) public returns (struct IPool.TokenAmount[] withdrawnAmounts)

Burns LP tokens sent to this contract. The router must ensure that the user gets sufficient output tokens.

burnSingle

  function burnSingle(
  ) public returns (uint256 amountOut)

Burns LP tokens sent to this contract and swaps one of the output tokens for another

i.e., the user gets a single token out by burning LP tokens.

swap

  function swap(
  ) public returns (uint256 amountOut)

Swaps one token for another. The router must prefund this contract and ensure there isn’t too much slippage.

flashSwap

  function flashSwap(
  ) public returns (uint256 amountOut)

Swaps one token for another with payload. The router must support swap callbacks and ensure there isn’t too much slippage.

updateBarFee

  function updateBarFee(
  ) public

Updates barFee for Trident protocol.

_processSwap

  function _processSwap(
  ) internal

_getReserves

  function _getReserves(
  ) internal returns (uint256 _reserve0, uint256 _reserve1)

_getReservesAndBalances

  function _getReservesAndBalances(
  ) internal returns (uint256 _reserve0, uint256 _reserve1, uint256 balance0, uint256 balance1)

_updateReserves

  function _updateReserves(
  ) internal

_balance

  function _balance(
  ) internal returns (uint256 balance0, uint256 balance1)

_getAmountOut

  function _getAmountOut(
  ) internal returns (uint256 dy)

_transfer

  function _transfer(
  ) internal

_computeLiquidity

  function _computeLiquidity(
  ) internal returns (uint256 liquidity)

Get D, the StableSwap invariant, based on a set of balances and a particular A. See the StableSwap paper for details.

Originally https://github.com/saddle-finance/saddle-contract/blob/0b76f7fb519e34b878aa1d58cffc8d8dc0572c12/contracts/SwapUtils.sol#L319.

Return Values:

Name	Type	Description
`liquidity`	uint256	The invariant, at the precision of the pool.

_computeLiquidityFromAdjustedBalances

  function _computeLiquidityFromAdjustedBalances(
  ) internal returns (uint256 computed)

_getY

  function _getY(
    uint256 x
  ) internal returns (uint256 y)

Calculate the new balances of the tokens given the indexes of the token that is swapped from (FROM) and the token that is swapped to (TO). This function is used as a helper function to calculate how much TO token the user should receive on swap.

Originally https://github.com/saddle-finance/saddle-contract/blob/0b76f7fb519e34b878aa1d58cffc8d8dc0572c12/contracts/SwapUtils.sol#L432.

Parameters:

Name	Type	Description
`x`	uint256	The new total amount of FROM token.

Return Values:

Name	Type	Description
`y`	uint256	The amount of TO token that should remain in the pool.

_mintFee

  function _mintFee(
  ) internal returns (uint256 _totalSupply, uint256 d)

_nonOptimalMintFee

  function _nonOptimalMintFee(
  ) internal returns (uint256 token0Fee, uint256 token1Fee)

This fee is charged to cover for swapFee when users add unbalanced liquidity.

getAssets

  function getAssets(
  ) public returns (address[] assets)

getAmountOut

  function getAmountOut(
  ) public returns (uint256 finalAmountOut)

getReserves

  function getReserves(
  ) public returns (uint256 _reserve0, uint256 _reserve1)

getVirtualPrice

  function getVirtualPrice(
  ) public returns (uint256 virtualPrice)

Events

Mint

  event Mint(
  )

Burn

  event Burn(
  )

Sync

  event Sync(
  )