> For the complete documentation index, see [llms.txt](https://docs.prl.one/buttonwood/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.prl.one/buttonwood/developers/tranche/bondcontroller.md).

# Bond

Controller for a ButtonTranche bond

Invariants:

* `totalDebt` should always equal the sum of all tranche tokens' `totalSupply()`

## API Documentation

## `init(address _trancheFactory, address _collateralToken, address _admin, uint256[] trancheRatios, uint256 _maturityDate)` (external)

Constructor for Tranche ERC20 token

## `deposit(uint256 amount)` (external)

Deposit `amount` tokens from `msg.sender`, get tranche tokens in return Requirements:

* `msg.sender` must have `approved` `amount` collateral tokens to this contract

## `mature()` (external)

Matures the bond. Disables deposits, fixes the redemption ratio, and distributes collateral to redemption pools Requirements:

* The bond is not already mature
* One of:
  * `msg.sender` is `owner`
  * `maturityDate` has passed

## `redeemMature(address tranche, uint256 amount)` (external)

Redeems some tranche tokens Requirements:

* The bond is mature
* `msg.sender` owns at least `amount` tranche tokens from address `tranche`
* `tranche` must be a valid tranche token on this bond

## `redeem(uint256[] amounts)` (external)

Redeems a slice of tranche tokens from all tranches. Returns collateral to the user proportionally to the amount of debt they are removing Requirements

* The bond is not mature
* The number of `amounts` is the same as the number of tranches
* The `amounts` are in equivalent ratio to the tranche order

## `getTrancheName(string collateralSymbol, uint256 index, uint256 _trancheCount) → string` (internal)

Get the string name for a tranche

## `getTrancheSymbol(string collateralSymbol, uint256 index, uint256 _trancheCount) → string` (internal)

Get the string symbol for a tranche

## `getTrancheLetter(uint256 index, uint256 _trancheCount) → string` (internal)

Get the string letter for a tranche index


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