Move Frontend interface to separate file

xeth/frontend.go

+package xeth
+
+import (
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+// Frontend should be implemented by users of XEth. Its methods are
+// called whenever XEth makes a decision that requires user input.
+type Frontend interface {
+	// UnlockAccount is called when a transaction needs to be signed
+	// but the key corresponding to the transaction's sender is
+	// locked.
+	//
+	// It should unlock the account with the given address and return
+	// true if unlocking succeeded.
+	UnlockAccount(address []byte) bool
+
+	// This is called for all transactions inititated through
+	// Transact. It should prompt the user to confirm the transaction
+	// and return true if the transaction was acknowledged.
+	//
+	// ConfirmTransaction is not used for Call transactions
+	// because they cannot change any state.
+	ConfirmTransaction(tx *types.Transaction) bool
+}
+
+// dummyFrontend is a non-interactive frontend that allows all
+// transactions but cannot not unlock any keys.
+type dummyFrontend struct{}
+
+func (dummyFrontend) UnlockAccount([]byte) bool                  { return false }
+func (dummyFrontend) ConfirmTransaction(*types.Transaction) bool { return true }

xeth/xeth.go

@@ -28,33 +28,6 @@ var (
 	defaultGas       = big.NewInt(90000)          //500000
 )
 
-// Frontend should be implemented by users of XEth. Its methods are
-// called whenever XEth makes a decision that requires user input.
-type Frontend interface {
-	// UnlockAccount is called when a transaction needs to be signed
-	// but the key corresponding to the transaction's sender is
-	// locked.
-	//
-	// It should unlock the account with the given address and return
-	// true if unlocking succeeded.
-	UnlockAccount(address []byte) bool
-
-	// This is called for all transactions inititated through
-	// Transact. It should prompt the user to confirm the transaction
-	// and return true if the transaction was acknowledged.
-	//
-	// ConfirmTransaction is not used for Call transactions
-	// because they cannot change any state.
-	ConfirmTransaction(tx *types.Transaction) bool
-}
-
-// dummyFrontend is a non-interactive frontend that allows all
-// transactions but cannot not unlock any keys.
-type dummyFrontend struct{}
-
-func (dummyFrontend) UnlockAccount([]byte) bool                  { return false }
-func (dummyFrontend) ConfirmTransaction(*types.Transaction) bool { return true }
-
 type XEth struct {
 	backend *eth.Ethereum
 	state   *State