{
    "Function": "_calculatePurchaseReturn",
    "File": "contracts/Bancor/BancorFormula.sol",
    "Parent Contracts": [],
    "High-Level Calls": [
        "SafeMath",
        "SafeMath",
        "SafeMath"
    ],
    "Internal Calls": [
        "require(bool)",
        "power"
    ],
    "Library Calls": [
        "add",
        "mul",
        "mul"
    ],
    "Low-Level Calls": [],
    "Code": "function _calculatePurchaseReturn(uint256 _supply, uint256 _connectorBalance, uint32 _connectorWeight, uint256 _depositAmount) internal view returns (uint256) {\n        // validate input\n        require(_supply > 0 && _connectorBalance > 0 && _connectorWeight > 0 && _connectorWeight <= MAX_WEIGHT);\n\n        // special case for 0 deposit amount\n        if (_depositAmount == 0)\n            return 0;\n\n        // special case if the weight = 100%\n        if (_connectorWeight == MAX_WEIGHT)\n            return _supply.mul(_depositAmount) / _connectorBalance;\n\n        uint256 result;\n        uint8 precision;\n        uint256 baseN = _depositAmount.add(_connectorBalance);\n        (result, precision) = power(baseN, _connectorBalance, _connectorWeight, MAX_WEIGHT);\n        uint256 temp = _supply.mul(result) >> precision;\n        return temp - _supply;\n    }"
}