Separate ERC827 interface in another contract

contracts/mocks/ERC827TokenMock.sol

@@ -1,11 +1,11 @@
 pragma solidity ^0.4.13;
 
 
-import '../token/ERC827.sol';
+import '../token/ERC827Token.sol';
 
 
 // mock class using ERC827 Token
-contract ERC827TokenMock is ERC827 {
+contract ERC827TokenMock is ERC827Token {
 
   function ERC827TokenMock(address initialAccount, uint256 initialBalance) {
     balances[initialAccount] = initialBalance;

contracts/token/ERC827.sol

@@ -1,125 +1,26 @@
 pragma solidity ^0.4.13;
 
-import "./StandardToken.sol";
+import "./ERC20.sol";
 
 /**
-   @title ERC827, an extension of ERC20 token standard
+   @title ERC827 interface, an extension of ERC20 token standard
 
-   Implementation the ERC827, following the ERC20 standard with extra
+   Interface of a ERC827 token, following the ERC20 standard with extra
    methods to transfer value and data and execute calls in transfers and
    approvals.
-   Uses OpenZeppelin StandardToken.
  */
-contract ERC827 is StandardToken {
+contract ERC827 is ERC20 {
 
-  /**
-     @dev Addition to ERC20 token methods. It allows to
-     approve the transfer of value and execute a call with the sent data.
+  function approve(
+    address _spender, uint256 _value, bytes _data
+  ) public returns (bool);
 
-     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
+  function transfer(
+    address _to, uint256 _value, bytes _data
+  ) public returns (bool);
 
-     @param _spender The address that will spend the funds.
-     @param _value The amount of tokens to be spent.
-     @param _data ABI-encoded contract call to call `_to` address.
-
-     @return true if the call function was executed successfully
-   */
-  function approve(address _spender, uint256 _value, bytes _data) public returns (bool) {
-    require(_spender != address(this));
-
-    super.approve(_spender, _value);
-
-    require(_spender.call(_data));
-
-    return true;
-  }
-
-  /**
-     @dev Addition to ERC20 token methods. Transfer tokens to a specified
-     address and execute a call with the sent data on the same transaction
-
-     @param _to address The address which you want to transfer to
-     @param _value uint256 the amout of tokens to be transfered
-     @param _data ABI-encoded contract call to call `_to` address.
-
-     @return true if the call function was executed successfully
-   */
-  function transfer(address _to, uint256 _value, bytes _data) public returns (bool) {
-    require(_to != address(this));
-
-    super.transfer(_to, _value);
-
-    require(_to.call(_data));
-    return true;
-  }
-
-  /**
-     @dev Addition to ERC20 token methods. Transfer tokens from one address to
-     another and make a contract call on the same transaction
-
-     @param _from The address which you want to send tokens from
-     @param _to The address which you want to transfer to
-     @param _value The amout of tokens to be transferred
-     @param _data ABI-encoded contract call to call `_to` address.
-
-     @return true if the call function was executed successfully
-   */
-  function transferFrom(address _from, address _to, uint256 _value, bytes _data) public returns (bool) {
-    require(_to != address(this));
-
-    super.transferFrom(_from, _to, _value);
-
-    require(_to.call(_data));
-    return true;
-  }
-
-  /**
-   * @dev Addition to StandardToken methods. Increase the amount of tokens that
-   * an owner allowed to a spender and execute a call with the sent data.
-   *
-   * approve should be called when allowed[_spender] == 0. To increment
-   * allowed value is better to use this function to avoid 2 calls (and wait until
-   * the first transaction is mined)
-   * From MonolithDAO Token.sol
-   * @param _spender The address which will spend the funds.
-   * @param _addedValue The amount of tokens to increase the allowance by.
-   * @param _data ABI-encoded contract call to call `_spender` address.
-   */
-  function increaseApproval(address _spender, uint _addedValue, bytes _data) public returns (bool) {
-    require(_spender != address(this));
-
-    super.approve(_spender, _addedValue);
-
-    require(_spender.call(_data));
-
-    return true;
-  }
-
-  /**
-   * @dev Addition to StandardToken methods. Decrease the amount of tokens that
-   * an owner allowed to a spender and execute a call with the sent data.
-   *
-   * approve should be called when allowed[_spender] == 0. To decrement
-   * allowed value is better to use this function to avoid 2 calls (and wait until
-   * the first transaction is mined)
-   * From MonolithDAO Token.sol
-   * @param _spender The address which will spend the funds.
-   * @param _subtractedValue The amount of tokens to decrease the allowance by.
-   * @param _data ABI-encoded contract call to call `_spender` address.
-   */
-  function decreaseApproval(address _spender, uint _subtractedValue, bytes _data) public returns (bool) {
-    require(_spender != address(this));
-
-    super.decreaseApproval(_spender, _subtractedValue);
-
-    require(_spender.call(_data));
-
-    return true;
-  }
+  function transferFrom(
+    address _from, address _to, uint256 _value, bytes _data
+  ) public returns (bool);
 
 }

contracts/token/ERC827Token.sol

@@ -0,0 +1,126 @@
+pragma solidity ^0.4.13;
+
+import "./ERC827.sol";
+import "./StandardToken.sol";
+
+/**
+   @title ERC827, an extension of ERC20 token standard
+
+   Implementation the ERC827, following the ERC20 standard with extra
+   methods to transfer value and data and execute calls in transfers and
+   approvals.
+   Uses OpenZeppelin StandardToken.
+ */
+contract ERC827Token is ERC827, StandardToken {
+
+  /**
+     @dev Addition to ERC20 token methods. It allows to
+     approve the transfer of value and execute a call with the sent data.
+
+     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
+
+     @param _spender The address that will spend the funds.
+     @param _value The amount of tokens to be spent.
+     @param _data ABI-encoded contract call to call `_to` address.
+
+     @return true if the call function was executed successfully
+   */
+  function approve(address _spender, uint256 _value, bytes _data) public returns (bool) {
+    require(_spender != address(this));
+
+    super.approve(_spender, _value);
+
+    require(_spender.call(_data));
+
+    return true;
+  }
+
+  /**
+     @dev Addition to ERC20 token methods. Transfer tokens to a specified
+     address and execute a call with the sent data on the same transaction
+
+     @param _to address The address which you want to transfer to
+     @param _value uint256 the amout of tokens to be transfered
+     @param _data ABI-encoded contract call to call `_to` address.
+
+     @return true if the call function was executed successfully
+   */
+  function transfer(address _to, uint256 _value, bytes _data) public returns (bool) {
+    require(_to != address(this));
+
+    super.transfer(_to, _value);
+
+    require(_to.call(_data));
+    return true;
+  }
+
+  /**
+     @dev Addition to ERC20 token methods. Transfer tokens from one address to
+     another and make a contract call on the same transaction
+
+     @param _from The address which you want to send tokens from
+     @param _to The address which you want to transfer to
+     @param _value The amout of tokens to be transferred
+     @param _data ABI-encoded contract call to call `_to` address.
+
+     @return true if the call function was executed successfully
+   */
+  function transferFrom(address _from, address _to, uint256 _value, bytes _data) public returns (bool) {
+    require(_to != address(this));
+
+    super.transferFrom(_from, _to, _value);
+
+    require(_to.call(_data));
+    return true;
+  }
+
+  /**
+   * @dev Addition to StandardToken methods. Increase the amount of tokens that
+   * an owner allowed to a spender and execute a call with the sent data.
+   *
+   * approve should be called when allowed[_spender] == 0. To increment
+   * allowed value is better to use this function to avoid 2 calls (and wait until
+   * the first transaction is mined)
+   * From MonolithDAO Token.sol
+   * @param _spender The address which will spend the funds.
+   * @param _addedValue The amount of tokens to increase the allowance by.
+   * @param _data ABI-encoded contract call to call `_spender` address.
+   */
+  function increaseApproval(address _spender, uint _addedValue, bytes _data) public returns (bool) {
+    require(_spender != address(this));
+
+    super.approve(_spender, _addedValue);
+
+    require(_spender.call(_data));
+
+    return true;
+  }
+
+  /**
+   * @dev Addition to StandardToken methods. Decrease the amount of tokens that
+   * an owner allowed to a spender and execute a call with the sent data.
+   *
+   * approve should be called when allowed[_spender] == 0. To decrement
+   * allowed value is better to use this function to avoid 2 calls (and wait until
+   * the first transaction is mined)
+   * From MonolithDAO Token.sol
+   * @param _spender The address which will spend the funds.
+   * @param _subtractedValue The amount of tokens to decrease the allowance by.
+   * @param _data ABI-encoded contract call to call `_spender` address.
+   */
+  function decreaseApproval(address _spender, uint _subtractedValue, bytes _data) public returns (bool) {
+    require(_spender != address(this));
+
+    super.decreaseApproval(_spender, _subtractedValue);
+
+    require(_spender.call(_data));
+
+    return true;
+  }
+
+}