Update ERC20.sol

contracts/open-zeppelin/ERC20.sol

@@ -10,21 +10,21 @@ import "./Address.sol";
 /**
  * @dev Implementation of the {IERC20} 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}.
- * For a generic mechanism see {ERC20PresetMinterPauser}.
+ * This implementation is agnostic to how tokens are created. This means
+ * a supply mechanism has to be added in a derived contract using {_mint}.
+ * For a generic mechanism, see {ERC20PresetMinterPauser}.
  *
- * TIP: For a detailed writeup see our guide
- * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
+ * TIP: For a detailed write-up, see our guide:
+ * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226 [How
  * to implement supply mechanisms].
  *
  * We have followed general OpenZeppelin guidelines: functions revert instead
- * of returning `false` on failure. This behavior is nonetheless conventional
+ * of returning `false` on failure. This behavior is conventional
  * and does not conflict with the expectations of ERC20 applications.
  *
  * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
  * This allows applications to reconstruct the allowance for all accounts just
- * by listening to said events. Other implementations of the EIP may not emit
+ * by listening to these events. Other implementations of the EIP may not emit
  * these events, as it isn't required by the specification.
  *
  * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
@@ -46,7 +46,7 @@ contract ERC20 is Context, IERC20 {
     uint8 private _decimals;
 
     /**
-     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
+     * @dev Sets the values for {name} and {symbol}, and initializes {decimals} with
      * a default value of 18.
      *
      * To select a different value for {decimals}, use {_setupDecimals}.
@@ -68,8 +68,7 @@ contract ERC20 is Context, IERC20 {
     }
 
     /**
-     * @dev Returns the symbol of the token, usually a shorter version of the
-     * name.
+     * @dev Returns the symbol of the token, usually a shorter version of the name.
      */
     function symbol() public view returns (string memory) {
         return _symbol;
@@ -78,13 +77,13 @@ contract ERC20 is Context, IERC20 {
     /**
      * @dev Returns the number of decimals used to get its user representation.
      * For example, if `decimals` equals `2`, a balance of `505` tokens should
-     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
+     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
      *
      * Tokens usually opt for a value of 18, imitating the relationship between
-     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
+     * Ether and Wei. This is the value {ERC20} uses unless {_setupDecimals} is
      * called.
      *
-     * NOTE: This information is only used for _display_ purposes: it in
+     * NOTE: This information is only used for _display_ purposes; it in
      * no way affects any of the arithmetic of the contract, including
      * {IERC20-balanceOf} and {IERC20-transfer}.
      */
@@ -142,7 +141,7 @@ contract ERC20 is Context, IERC20 {
      * @dev See {IERC20-transferFrom}.
      *
      * Emits an {Approval} event indicating the updated allowance. This is not
-     * required by the EIP. See the note at the beginning of {ERC20};
+     * required by the EIP. See the note at the beginning of {ERC20}.
      *
      * Requirements:
      * - `sender` and `recipient` cannot be the zero address.
@@ -152,7 +151,11 @@ contract ERC20 is Context, IERC20 {
      */
     function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
         _transfer(sender, recipient, amount);
-        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
+        _approve(
+            sender,
+            _msgSender(),
+            _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance")
+        );
         return true;
     }
 
@@ -188,15 +191,19 @@ contract ERC20 is Context, IERC20 {
      * `subtractedValue`.
      */
     function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
-        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
+        _approve(
+            _msgSender(),
+            spender,
+            _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero")
+        );
         return true;
     }
 
     /**
-     * @dev Moves tokens `amount` from `sender` to `recipient`.
+     * @dev Moves `amount` tokens from `sender` to `recipient`.
      *
-     * This is internal function is equivalent to {transfer}, and can be used to
-     * e.g. implement automatic token fees, slashing mechanisms, etc.
+     * This internal function is equivalent to {transfer}, and can be used to
+     * e.g., implement automatic token fees, slashing mechanisms, etc.
      *
      * Emits a {Transfer} event.
      *
@@ -217,14 +224,15 @@ contract ERC20 is Context, IERC20 {
         emit Transfer(sender, recipient, amount);
     }
 
-    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
+    /** 
+     * @dev Creates `amount` tokens and assigns them to `account`, increasing
      * the total supply.
      *
      * Emits a {Transfer} event with `from` set to the zero address.
      *
-     * Requirements
+     * Requirements:
      *
-     * - `to` cannot be the zero address.
+     * - `account` cannot be the zero address.
      */
     function _mint(address account, uint256 amount) internal virtual {
         require(account != address(0), "ERC20: mint to the zero address");
@@ -242,7 +250,7 @@ contract ERC20 is Context, IERC20 {
      *
      * Emits a {Transfer} event with `to` set to the zero address.
      *
-     * Requirements
+     * Requirements:
      *
      * - `account` cannot be the zero address.
      * - `account` must have at least `amount` tokens.
@@ -258,10 +266,10 @@ contract ERC20 is Context, IERC20 {
     }
 
     /**
-     * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
+     * @dev Sets `amount` as the allowance of `spender` over the `owner`'s tokens.
      *
-     * This is internal function is equivalent to `approve`, and can be used to
-     * e.g. set automatic allowances for certain subsystems, etc.
+     * This internal function is equivalent to `approve`, and can be used to
+     * e.g., set automatic allowances for certain subsystems, etc.
      *
      * Emits an {Approval} event.
      *
@@ -279,7 +287,7 @@ contract ERC20 is Context, IERC20 {
     }
 
     /**
-     * @dev Sets {decimals} to a value other than the default one of 18.
+     * @dev Sets {decimals} to a value other than the default of 18.
      *
      * WARNING: This function should only be called from the constructor. Most
      * applications that interact with token contracts will not expect
@@ -296,12 +304,12 @@ contract ERC20 is Context, IERC20 {
      * Calling conditions:
      *
      * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
-     * will be to transferred to `to`.
+     * will be transferred to `to`.
      * - when `from` is zero, `amount` tokens will be minted for `to`.
      * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
      * - `from` and `to` are never both zero.
      *
-     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
+     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks [Using Hooks].
      */
     function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
-}
+}