Regexp catching keywords inside strings

[DefiCake]

FileAnalyzer divides the source code in "groups" based on the regexp const exportRegex = /(contract|library|interface)\s+([a-zA-Z_$][a-zA-Z_$0-9]*)\s*([\s\S]*?)\{/g;.

This grouping breaks if a line contains a keyword inside a string. For example:

require(!to.isContract(), "ERC777: token recipient contract has no implementer for ERC777TokensRecipient");

Inside the implementation of open-zeppelin's ERC-777:

pragma solidity 0.5.7;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, "SafeMath: division by zero");
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0, "SafeMath: modulo by zero");
        return a % b;
    }
}






/**
 * @dev Interface of the ERC777Token standard as defined in the EIP.
 *
 * This contract uses the
 * [ERC1820 registry standard](https://eips.ethereum.org/EIPS/eip-1820) to let
 * token holders and recipients react to token movements by using setting implementers
 * for the associated interfaces in said registry. See `IERC1820Registry` and
 * `ERC1820Implementer`.
 */
interface IERC777 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the smallest part of the token that is not divisible. This
     * means all token operations (creation, movement and destruction) must have
     * amounts that are a multiple of this number.
     *
     * For most token contracts, this value will equal 1.
     */
    function granularity() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by an account (`owner`).
     */
    function balanceOf(address owner) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * If send or receive hooks are registered for the caller and `recipient`,
     * the corresponding functions will be called with `data` and empty
     * `operatorData`. See `IERC777Sender` and `IERC777Recipient`.
     *
     * Emits a `Sent` event.
     *
     * Requirements
     *
     * - the caller must have at least `amount` tokens.
     * - `recipient` cannot be the zero address.
     * - if `recipient` is a contract, it must implement the `tokensReceived`
     * interface.
     */
    function send(address recipient, uint256 amount, bytes calldata data) external;

    /**
     * @dev Destroys `amount` tokens from the caller's account, reducing the
     * total supply.
     *
     * If a send hook is registered for the caller, the corresponding function
     * will be called with `data` and empty `operatorData`. See `IERC777Sender`.
     *
     * Emits a `Burned` event.
     *
     * Requirements
     *
     * - the caller must have at least `amount` tokens.
     */
    function burn(uint256 amount, bytes calldata data) external;

    /**
     * @dev Returns true if an account is an operator of `tokenHolder`.
     * Operators can send and burn tokens on behalf of their owners. All
     * accounts are their own operator.
     *
     * See `operatorSend` and `operatorBurn`.
     */
    function isOperatorFor(address operator, address tokenHolder) external view returns (bool);

    /**
     * @dev Make an account an operator of the caller.
     *
     * See `isOperatorFor`.
     *
     * Emits an `AuthorizedOperator` event.
     *
     * Requirements
     *
     * - `operator` cannot be calling address.
     */
    function authorizeOperator(address operator) external;

    /**
     * @dev Make an account an operator of the caller.
     *
     * See `isOperatorFor` and `defaultOperators`.
     *
     * Emits a `RevokedOperator` event.
     *
     * Requirements
     *
     * - `operator` cannot be calling address.
     */
    function revokeOperator(address operator) external;

    /**
     * @dev Returns the list of default operators. These accounts are operators
     * for all token holders, even if `authorizeOperator` was never called on
     * them.
     *
     * This list is immutable, but individual holders may revoke these via
     * `revokeOperator`, in which case `isOperatorFor` will return false.
     */
    function defaultOperators() external view returns (address[] memory);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient`. The caller must
     * be an operator of `sender`.
     *
     * If send or receive hooks are registered for `sender` and `recipient`,
     * the corresponding functions will be called with `data` and
     * `operatorData`. See `IERC777Sender` and `IERC777Recipient`.
     *
     * Emits a `Sent` event.
     *
     * Requirements
     *
     * - `sender` cannot be the zero address.
     * - `sender` must have at least `amount` tokens.
     * - the caller must be an operator for `sender`.
     * - `recipient` cannot be the zero address.
     * - if `recipient` is a contract, it must implement the `tokensReceived`
     * interface.
     */
    function operatorSend(
        address sender,
        address recipient,
        uint256 amount,
        bytes calldata data,
        bytes calldata operatorData
    ) external;

    /**
     * @dev Destoys `amount` tokens from `account`, reducing the total supply.
     * The caller must be an operator of `account`.
     *
     * If a send hook is registered for `account`, the corresponding function
     * will be called with `data` and `operatorData`. See `IERC777Sender`.
     *
     * Emits a `Burned` event.
     *
     * Requirements
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     * - the caller must be an operator for `account`.
     */
    function operatorBurn(
        address account,
        uint256 amount,
        bytes calldata data,
        bytes calldata operatorData
    ) external;

    event Sent(
        address indexed operator,
        address indexed from,
        address indexed to,
        uint256 amount,
        bytes data,
        bytes operatorData
    );

    event Minted(address indexed operator, address indexed to, uint256 amount, bytes data, bytes operatorData);

    event Burned(address indexed operator, address indexed from, uint256 amount, bytes data, bytes operatorData);

    event AuthorizedOperator(address indexed operator, address indexed tokenHolder);

    event RevokedOperator(address indexed operator, address indexed tokenHolder);
}



/**
 * @dev Interface of the ERC777TokensRecipient standard as defined in the EIP.
 *
 * Accounts can be notified of `IERC777` tokens being sent to them by having a
 * contract implement this interface (contract holders can be their own
 * implementer) and registering it on the
 * [ERC1820 global registry](https://eips.ethereum.org/EIPS/eip-1820).
 *
 * See `IERC1820Registry` and `ERC1820Implementer`.
 */
interface IERC777Recipient {
    /**
     * @dev Called by an `IERC777` token contract whenever tokens are being
     * moved or created into a registered account (`to`). The type of operation
     * is conveyed by `from` being the zero address or not.
     *
     * This call occurs _after_ the token contract's state is updated, so
     * `IERC777.balanceOf`, etc., can be used to query the post-operation state.
     *
     * This function may revert to prevent the operation from being executed.
     */
    function tokensReceived(
        address operator,
        address from,
        address to,
        uint amount,
        bytes calldata userData,
        bytes calldata operatorData
    ) external;
}



/**
 * @dev Interface of the ERC777TokensSender standard as defined in the EIP.
 *
 * `IERC777` Token holders can be notified of operations performed on their
 * tokens by having a contract implement this interface (contract holders can be
 *  their own implementer) and registering it on the
 * [ERC1820 global registry](https://eips.ethereum.org/EIPS/eip-1820).
 *
 * See `IERC1820Registry` and `ERC1820Implementer`.
 */
interface IERC777Sender {
    /**
     * @dev Called by an `IERC777` token contract whenever a registered holder's
     * (`from`) tokens are about to be moved or destroyed. The type of operation
     * is conveyed by `to` being the zero address or not.
     *
     * This call occurs _before_ the token contract's state is updated, so
     * `IERC777.balanceOf`, etc., can be used to query the pre-operation state.
     *
     * This function may revert to prevent the operation from being executed.
     */
    function tokensToSend(
        address operator,
        address from,
        address to,
        uint amount,
        bytes calldata userData,
        bytes calldata operatorData
    ) external;
}



/**
 * @dev Interface of the ERC20 standard as defined in the EIP. Does not include
 * the optional functions; to access them see `ERC20Detailed`.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a `Transfer` event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through `transferFrom`. This is
     * zero by default.
     *
     * This value changes when `approve` or `transferFrom` are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * > Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an `Approval` event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a `Transfer` event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to `approve`. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}




/**
 * @dev Collection of functions related to the address type,
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * This test is non-exhaustive, and there may be false-negatives: during the
     * execution of a contract's constructor, its address will be reported as
     * not containing a contract.
     *
     * > It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies in extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }
}



/**
 * @dev Interface of the global ERC1820 Registry, as defined in the
 * [EIP](https://eips.ethereum.org/EIPS/eip-1820). Accounts may register
 * implementers for interfaces in this registry, as well as query support.
 *
 * Implementers may be shared by multiple accounts, and can also implement more
 * than a single interface for each account. Contracts can implement interfaces
 * for themselves, but externally-owned accounts (EOA) must delegate this to a
 * contract.
 *
 * `IERC165` interfaces can also be queried via the registry.
 *
 * For an in-depth explanation and source code analysis, see the EIP text.
 */
interface IERC1820Registry {
    /**
     * @dev Sets `newManager` as the manager for `account`. A manager of an
     * account is able to set interface implementers for it.
     *
     * By default, each account is its own manager. Passing a value of `0x0` in
     * `newManager` will reset the manager to this initial state.
     *
     * Emits a `ManagerChanged` event.
     *
     * Requirements:
     *
     * - the caller must be the current manager for `account`.
     */
    function setManager(address account, address newManager) external;

    /**
     * @dev Returns the manager for `account`.
     *
     * See `setManager`.
     */
    function getManager(address account) external view returns (address);

    /**
     * @dev Sets the `implementer` contract as `account`'s implementer for
     * `interfaceHash`.
     *
     * `account` being the zero address is an alias for the caller's address.
     * The zero address can also be used in `implementer` to remove an old one.
     *
     * See `interfaceHash` to learn how these are created.
     *
     * Emits an `InterfaceImplementerSet` event.
     *
     * Requirements:
     *
     * - the caller must be the current manager for `account`.
     * - `interfaceHash` must not be an `IERC165` interface id (i.e. it must not
     * end in 28 zeroes).
     * - `implementer` must implement `IERC1820Implementer` and return true when
     * queried for support, unless `implementer` is the caller. See
     * `IERC1820Implementer.canImplementInterfaceForAddress`.
     */
    function setInterfaceImplementer(address account, bytes32 interfaceHash, address implementer) external;

    /**
     * @dev Returns the implementer of `interfaceHash` for `account`. If no such
     * implementer is registered, returns the zero address.
     *
     * If `interfaceHash` is an `IERC165` interface id (i.e. it ends with 28
     * zeroes), `account` will be queried for support of it.
     *
     * `account` being the zero address is an alias for the caller's address.
     */
    function getInterfaceImplementer(address account, bytes32 interfaceHash) external view returns (address);

    /**
     * @dev Returns the interface hash for an `interfaceName`, as defined in the
     * corresponding
     * [section of the EIP](https://eips.ethereum.org/EIPS/eip-1820#interface-name).
     */
    function interfaceHash(string calldata interfaceName) external pure returns (bytes32);

    /**
     *  @notice Updates the cache with whether the contract implements an ERC165 interface or not.
     *  @param account Address of the contract for which to update the cache.
     *  @param interfaceId ERC165 interface for which to update the cache.
     */
    function updateERC165Cache(address account, bytes4 interfaceId) external;

    /**
     *  @notice Checks whether a contract implements an ERC165 interface or not.
     *  If the result is not cached a direct lookup on the contract address is performed.
     *  If the result is not cached or the cached value is out-of-date, the cache MUST be updated manually by calling
     *  'updateERC165Cache' with the contract address.
     *  @param account Address of the contract to check.
     *  @param interfaceId ERC165 interface to check.
     *  @return True if `account.address()` implements `interfaceId`, false otherwise.
     */
    function implementsERC165Interface(address account, bytes4 interfaceId) external view returns (bool);

    /**
     *  @notice Checks whether a contract implements an ERC165 interface or not without using nor updating the cache.
     *  @param account Address of the contract to check.
     *  @param interfaceId ERC165 interface to check.
     *  @return True if `account.address()` implements `interfaceId`, false otherwise.
     */
    function implementsERC165InterfaceNoCache(address account, bytes4 interfaceId) external view returns (bool);

    event InterfaceImplementerSet(address indexed account, bytes32 indexed interfaceHash, address indexed implementer);

    event ManagerChanged(address indexed account, address indexed newManager);
}


/**
 * @dev Implementation of the `IERC777` interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using `_mint`.
 *
 * Support for ERC20 is included in this contract, as specified by the EIP: both
 * the ERC777 and ERC20 interfaces can be safely used when interacting with it.
 * Both `IERC777.Sent` and `IERC20.Transfer` events are emitted on token
 * movements.
 *
 * Additionally, the `granularity` value is hard-coded to `1`, meaning that there
 * are no special restrictions in the amount of tokens that created, moved, or
 * destroyed. This makes integration with ERC20 applications seamless.
 */
contract ERC777 is IERC777, IERC20 {
    using SafeMath for uint256;
    using Address for address;

    IERC1820Registry private _erc1820 = IERC1820Registry(0x1820a4B7618BdE71Dce8cdc73aAB6C95905faD24);

    mapping(address => uint256) private _balances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    // We inline the result of the following hashes because Solidity doesn't resolve them at compile time.
    // See https://github.com/ethereum/solidity/issues/4024.

    // keccak256("ERC777TokensSender")
    bytes32 constant private TOKENS_SENDER_INTERFACE_HASH =
        0x29ddb589b1fb5fc7cf394961c1adf5f8c6454761adf795e67fe149f658abe895;

    // keccak256("ERC777TokensRecipient")
    bytes32 constant private TOKENS_RECIPIENT_INTERFACE_HASH =
        0xb281fc8c12954d22544db45de3159a39272895b169a852b314f9cc762e44c53b;

    // This isn't ever read from - it's only used to respond to the defaultOperators query.
    address[] private _defaultOperatorsArray;

    // Immutable, but accounts may revoke them (tracked in __revokedDefaultOperators).
    mapping(address => bool) private _defaultOperators;

    // For each account, a mapping of its operators and revoked default operators.
    mapping(address => mapping(address => bool)) private _operators;
    mapping(address => mapping(address => bool)) private _revokedDefaultOperators;

    // ERC20-allowances
    mapping (address => mapping (address => uint256)) private _allowances;

    /**
     * @dev `defaultOperators` may be an empty array.
     */
    constructor(
        string memory name,
        string memory symbol,
        address[] memory defaultOperators
    ) public {
        _name = name;
        _symbol = symbol;

        _defaultOperatorsArray = defaultOperators;
        for (uint256 i = 0; i < _defaultOperatorsArray.length; i++) {
            _defaultOperators[_defaultOperatorsArray[i]] = true;
        }

        // register interfaces
        _erc1820.setInterfaceImplementer(address(this), keccak256("ERC777Token"), address(this));
        _erc1820.setInterfaceImplementer(address(this), keccak256("ERC20Token"), address(this));
    }

    /**
     * @dev See `IERC777.name`.
     */
    function name() public view returns (string memory) {
        return _name;
    }

    /**
     * @dev See `IERC777.symbol`.
     */
    function symbol() public view returns (string memory) {
        return _symbol;
    }

    /**
     * @dev See `ERC20Detailed.decimals`.
     *
     * Always returns 18, as per the
     * [ERC777 EIP](https://eips.ethereum.org/EIPS/eip-777#backward-compatibility).
     */
    function decimals() public pure returns (uint8) {
        return 18;
    }

    /**
     * @dev See `IERC777.granularity`.
     *
     * This implementation always returns `1`.
     */
    function granularity() public view returns (uint256) {
        return 1;
    }

    /**
     * @dev See `IERC777.totalSupply`.
     */
    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev Returns the amount of tokens owned by an account (`tokenHolder`).
     */
    function balanceOf(address tokenHolder) public view returns (uint256) {
        return _balances[tokenHolder];
    }

    /**
     * @dev See `IERC777.send`.
     *
     * Also emits a `Transfer` event for ERC20 compatibility.
     */
    function send(address recipient, uint256 amount, bytes calldata data) external {
        _send(msg.sender, msg.sender, recipient, amount, data, "", true);
    }

    /**
     * @dev See `IERC20.transfer`.
     *
     * Unlike `send`, `recipient` is _not_ required to implement the `tokensReceived`
     * interface if it is a contract.
     *
     * Also emits a `Sent` event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool) {
        require(recipient != address(0), "ERC777: transfer to the zero address");

        address from = msg.sender;

        _callTokensToSend(from, from, recipient, amount, "", "");

        _move(from, from, recipient, amount, "", "");

        _callTokensReceived(from, from, recipient, amount, "", "", false);

        return true;
    }

    /**
     * @dev See `IERC777.burn`.
     *
     * Also emits a `Transfer` event for ERC20 compatibility.
     */
    function burn(uint256 amount, bytes calldata data) external {
        _burn(msg.sender, msg.sender, amount, data, "");
    }

    /**
     * @dev See `IERC777.isOperatorFor`.
     */
    function isOperatorFor(
        address operator,
        address tokenHolder
    ) public view returns (bool) {
        return operator == tokenHolder ||
            (_defaultOperators[operator] && !_revokedDefaultOperators[tokenHolder][operator]) ||
            _operators[tokenHolder][operator];
    }

    /**
     * @dev See `IERC777.authorizeOperator`.
     */
    function authorizeOperator(address operator) external {
        require(msg.sender != operator, "ERC777: authorizing self as operator");

        if (_defaultOperators[operator]) {
            delete _revokedDefaultOperators[msg.sender][operator];
        } else {
            _operators[msg.sender][operator] = true;
        }

        emit AuthorizedOperator(operator, msg.sender);
    }

    /**
     * @dev See `IERC777.revokeOperator`.
     */
    function revokeOperator(address operator) external {
        require(operator != msg.sender, "ERC777: revoking self as operator");

        if (_defaultOperators[operator]) {
            _revokedDefaultOperators[msg.sender][operator] = true;
        } else {
            delete _operators[msg.sender][operator];
        }

        emit RevokedOperator(operator, msg.sender);
    }

    /**
     * @dev See `IERC777.defaultOperators`.
     */
    function defaultOperators() public view returns (address[] memory) {
        return _defaultOperatorsArray;
    }

    /**
     * @dev See `IERC777.operatorSend`.
     *
     * Emits `Sent` and `Transfer` events.
     */
    function operatorSend(
        address sender,
        address recipient,
        uint256 amount,
        bytes calldata data,
        bytes calldata operatorData
    )
    external
    {
        require(isOperatorFor(msg.sender, sender), "ERC777: caller is not an operator for holder");
        _send(msg.sender, sender, recipient, amount, data, operatorData, true);
    }

    /**
     * @dev See `IERC777.operatorBurn`.
     *
     * Emits `Sent` and `Transfer` events.
     */
    function operatorBurn(address account, uint256 amount, bytes calldata data, bytes calldata operatorData) external {
        require(isOperatorFor(msg.sender, account), "ERC777: caller is not an operator for holder");
        _burn(msg.sender, account, amount, data, operatorData);
    }

    /**
     * @dev See `IERC20.allowance`.
     *
     * Note that operator and allowance concepts are orthogonal: operators may
     * not have allowance, and accounts with allowance may not be operators
     * themselves.
     */
    function allowance(address holder, address spender) public view returns (uint256) {
        return _allowances[holder][spender];
    }

    /**
     * @dev See `IERC20.approve`.
     *
     * Note that accounts cannot have allowance issued by their operators.
     */
    function approve(address spender, uint256 value) external returns (bool) {
        address holder = msg.sender;
        _approve(holder, spender, value);
        return true;
    }

   /**
    * @dev See `IERC20.transferFrom`.
    *
    * Note that operator and allowance concepts are orthogonal: operators cannot
    * call `transferFrom` (unless they have allowance), and accounts with
    * allowance cannot call `operatorSend` (unless they are operators).
    *
    * Emits `Sent` and `Transfer` events.
    */
    function transferFrom(address holder, address recipient, uint256 amount) external returns (bool) {
        require(recipient != address(0), "ERC777: transfer to the zero address");
        require(holder != address(0), "ERC777: transfer from the zero address");

        address spender = msg.sender;

        _callTokensToSend(spender, holder, recipient, amount, "", "");

        _move(spender, holder, recipient, amount, "", "");
        _approve(holder, spender, _allowances[holder][spender].sub(amount));

        _callTokensReceived(spender, holder, recipient, amount, "", "", false);

        return true;
    }

    /**
     * @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * If a send hook is registered for `raccount`, the corresponding function
     * will be called with `operator`, `data` and `operatorData`.
     *
     * See `IERC777Sender` and `IERC777Recipient`.
     *
     * Emits `Sent` and `Transfer` events.
     *
     * Requirements
     *
     * - `account` cannot be the zero address.
     * - if `account` is a contract, it must implement the `tokensReceived`
     * interface.
     */
    function _mint(
        address operator,
        address account,
        uint256 amount,
        bytes memory userData,
        bytes memory operatorData
    )
    internal
    {
        require(account != address(0), "ERC777: mint to the zero address");

        // Update state variables
        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);

        _callTokensReceived(operator, address(0), account, amount, userData, operatorData, true);

        emit Minted(operator, account, amount, userData, operatorData);
        emit Transfer(address(0), account, amount);
    }

    /**
     * @dev Send tokens
     * @param operator address operator requesting the transfer
     * @param from address token holder address
     * @param to address recipient address
     * @param amount uint256 amount of tokens to transfer
     * @param userData bytes extra information provided by the token holder (if any)
     * @param operatorData bytes extra information provided by the operator (if any)
     * @param requireReceptionAck if true, contract recipients are required to implement ERC777TokensRecipient
     */
    function _send(
        address operator,
        address from,
        address to,
        uint256 amount,
        bytes memory userData,
        bytes memory operatorData,
        bool requireReceptionAck
    )
        private
    {
        require(from != address(0), "ERC777: send from the zero address");
        require(to != address(0), "ERC777: send to the zero address");

        _callTokensToSend(operator, from, to, amount, userData, operatorData);

        _move(operator, from, to, amount, userData, operatorData);

        _callTokensReceived(operator, from, to, amount, userData, operatorData, requireReceptionAck);
    }

    /**
     * @dev Burn tokens
     * @param operator address operator requesting the operation
     * @param from address token holder address
     * @param amount uint256 amount of tokens to burn
     * @param data bytes extra information provided by the token holder
     * @param operatorData bytes extra information provided by the operator (if any)
     */
    function _burn(
        address operator,
        address from,
        uint256 amount,
        bytes memory data,
        bytes memory operatorData
    )
        private
    {
        require(from != address(0), "ERC777: burn from the zero address");

        _callTokensToSend(operator, from, address(0), amount, data, operatorData);

        // Update state variables
        _totalSupply = _totalSupply.sub(amount);
        _balances[from] = _balances[from].sub(amount);

        emit Burned(operator, from, amount, data, operatorData);
        emit Transfer(from, address(0), amount);
    }

    function _move(
        address operator,
        address from,
        address to,
        uint256 amount,
        bytes memory userData,
        bytes memory operatorData
    )
        private
    {
        _balances[from] = _balances[from].sub(amount);
        _balances[to] = _balances[to].add(amount);

        emit Sent(operator, from, to, amount, userData, operatorData);
        emit Transfer(from, to, amount);
    }

    function _approve(address holder, address spender, uint256 value) private {
        // TODO: restore this require statement if this function becomes internal, or is called at a new callsite. It is
        // currently unnecessary.
        //require(holder != address(0), "ERC777: approve from the zero address");
        require(spender != address(0), "ERC777: approve to the zero address");

        _allowances[holder][spender] = value;
        emit Approval(holder, spender, value);
    }

    /**
     * @dev Call from.tokensToSend() if the interface is registered
     * @param operator address operator requesting the transfer
     * @param from address token holder address
     * @param to address recipient address
     * @param amount uint256 amount of tokens to transfer
     * @param userData bytes extra information provided by the token holder (if any)
     * @param operatorData bytes extra information provided by the operator (if any)
     */
    function _callTokensToSend(
        address operator,
        address from,
        address to,
        uint256 amount,
        bytes memory userData,
        bytes memory operatorData
    )
        private
    {
        address implementer = _erc1820.getInterfaceImplementer(from, TOKENS_SENDER_INTERFACE_HASH);
        if (implementer != address(0)) {
            IERC777Sender(implementer).tokensToSend(operator, from, to, amount, userData, operatorData);
        }
    }

    /**
     * @dev Call to.tokensReceived() if the interface is registered. Reverts if the recipient is a contract but
     * tokensReceived() was not registered for the recipient
     * @param operator address operator requesting the transfer
     * @param from address token holder address
     * @param to address recipient address
     * @param amount uint256 amount of tokens to transfer
     * @param userData bytes extra information provided by the token holder (if any)
     * @param operatorData bytes extra information provided by the operator (if any)
     * @param requireReceptionAck if true, contract recipients are required to implement ERC777TokensRecipient
     */
    function _callTokensReceived(
        address operator,
        address from,
        address to,
        uint256 amount,
        bytes memory userData,
        bytes memory operatorData,
        bool requireReceptionAck
    )
        private
    {
        address implementer = _erc1820.getInterfaceImplementer(to, TOKENS_RECIPIENT_INTERFACE_HASH);
        if (implementer != address(0)) {
            IERC777Recipient(implementer).tokensReceived(operator, from, to, amount, userData, operatorData);
        } else if (requireReceptionAck) {
            require(!to.isContract(), "ERC777: token recipient contract has no implementer for ERC777TokensRecipient");
        }
    }
}






contract Ownable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), _owner);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(isOwner(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Returns true if the caller is the current owner.
     */
    function isOwner() public view returns (bool) {
        return msg.sender == _owner;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * > Note: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public onlyOwner {
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     */
    function _transferOwnership(address newOwner) internal {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}


/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * Based on openzeppelin Pausable contract, modified to give the pause function to the owner.
 */
contract Pausable is Ownable {
    /**
     * @dev Emitted when the pause is triggered by a pauser (`account`).
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by a pauser (`account`).
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state. Assigns the Pauser role
     * to the deployer.
     */
    constructor () internal {
        _paused = false;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view returns (bool) {
        return _paused;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     */
    modifier whenNotPaused() {
        require(!_paused);
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     */
    modifier whenPaused() {
        require(_paused);
        _;
    }

    /**
     * @dev Called by the owner, triggers stopped state.
     */
    function pause() public onlyOwner whenNotPaused {
        _paused = true;
        emit Paused(msg.sender);
    }

    /**
     * @dev Called by the owner, returns to normal state.
     */
    function unpause() public onlyOwner whenPaused {
        _paused = false;
        emit Unpaused(msg.sender);
    }
}


contract TestToken is Pausable, ERC777 {
  using SafeMath for uint256;
  
  uint256 constant public preAssigned = 300000000000000000000000000; // 300 hundred millions of tokens

  event LogReward(
    address indexed sender,
    address indexed origin,
    address indexed to,
    uint256 amount
  );

  constructor(
    string memory name,
    string memory symbol,
    address[] memory defaultOperators
  ) ERC777(name, symbol, defaultOperators)
    public {
      _mint(msg.sender, msg.sender, preAssigned, "", "");
      _mint(msg.sender, msg.sender, preAssigned, "", "");
      _mint(msg.sender, msg.sender, preAssigned, "", "");
  }
  

}

In this case the contract keyword gets detected and sol-merger spawns a new group. The next group (Ownable) gets wrong syntax, so I think it gets removed.

A workaround right now would be to avoid keywords inside the require statements (or any other string) in the solidity file.

I am thinking of a better way to do the grouping right now, or at least provisionally avoid the collision the contract keyword.

[RyuuGan]

Hello @rrodriguezreche,

Can you please provide a small contract to reproduce this issue? Or should I use the code above to check it?

Basically I need some steps to reproduce the issue?

Basically if you are using library directly, you should use analyze method, to get imports and exports, because analyzeImports and analyzeExports are not working properly with comments.

Best regards

[DefiCake]

Hi @RyuuGan , the above code can do with the reproduction, but I 'll have something prepared, I hope at the end of today, with a smaller stub and a example repository. I uploaded https://github.com/rrodriguezreche/verify-bug as an example for the truffle-plugin-verify (which uses this library), because I thought originally that the issue was with them (rkalis/truffle-plugin-verify#25), but as I debugged it a little more, I found the conflicting code was here.

Regards!

[DefiCake]

Hi @RyuuGan , sorry for the delay. Attaching here a minimal repository to reproduce: https://github.com/rrodriguezreche/sol-merger-bug

[RyuuGan]

Should be fixed in 1.2.0