fix examples

examples/factory/Exchange.vy

@@ -1,18 +1,18 @@
 #pragma version >0.3.10
 
-from ethereum.ercs import ERC20
+from ethereum.ercs import IERC20
 
 
 interface Factory:
     def register(): nonpayable
 
 
-token: public(ERC20)
+token: public(IERC20)
 factory: Factory
 
 
 @deploy
-def __init__(_token: ERC20, _factory: Factory):
+def __init__(_token: IERC20, _factory: Factory):
     self.token = _token
     self.factory = _factory
 

examples/factory/Factory.vy

@@ -1,16 +1,16 @@
 #pragma version >0.3.10
 
-from ethereum.ercs import ERC20
+from ethereum.ercs import IERC20
 
 interface Exchange:
-    def token() -> ERC20: view
+    def token() -> IERC20: view
     def receive(_from: address, _amt: uint256): nonpayable
     def transfer(_to: address, _amt: uint256): nonpayable
 
 
 exchange_codehash: public(bytes32)
 # Maps token addresses to exchange addresses
-exchanges: public(HashMap[ERC20, Exchange])
+exchanges: public(HashMap[IERC20, Exchange])
 
 
 @deploy
@@ -39,7 +39,7 @@ def register():
 
 
 @external
-def trade(_token1: ERC20, _token2: ERC20, _amt: uint256):
+def trade(_token1: IERC20, _token2: IERC20, _amt: uint256):
     # Perform a straight exchange of token1 to token 2 (1:1 price)
     # NOTE: Any practical implementation would need to solve the price oracle problem
     self.exchanges[_token1].receive(msg.sender, _amt)

examples/market_maker/on_chain_market_maker.vy

@@ -1,14 +1,14 @@
 #pragma version >0.3.10
 
-from ethereum.ercs import ERC20
+from ethereum.ercs import IERC20
 
 
 totalEthQty: public(uint256)
 totalTokenQty: public(uint256)
 # Constant set in `initiate` that's used to calculate
 # the amount of ether/tokens that are exchanged
 invariant: public(uint256)
-token_address: ERC20
+token_address: IERC20
 owner: public(address)
 
 # Sets the on chain market maker with its owner, initial token quantity,
@@ -17,7 +17,7 @@ owner: public(address)
 @payable
 def initiate(token_addr: address, token_quantity: uint256):
     assert self.invariant == 0
-    self.token_address = ERC20(token_addr)
+    self.token_address = IERC20(token_addr)
     self.token_address.transferFrom(msg.sender, self, token_quantity)
     self.owner = msg.sender
     self.totalEthQty = msg.value

examples/tokens/ERC4626.vy

@@ -53,7 +53,7 @@ event Withdraw:
 
 
 @deploy
-def __init__(asset: ERC20):
+def __init__(asset: IERC20):
     self.asset = asset