add BalanceChangeReason String() for better logging

core/tracing/hooks.go

@@ -214,6 +214,44 @@ const (
 	BalanceDecreaseSelfdestructBurn BalanceChangeReason = 14
 )
 
+// String returns a string representation of the reason.
+func (r BalanceChangeReason) String() string {
+	switch r {
+	case BalanceChangeUnspecified:
+		return "BalanceChangeUnspecified"
+	case BalanceIncreaseRewardMineUncle:
+		return "BalanceIncreaseRewardMineUncle"
+	case BalanceIncreaseRewardMineBlock:
+		return "BalanceIncreaseRewardMineBlock"
+	case BalanceIncreaseWithdrawal:
+		return "BalanceIncreaseWithdrawal"
+	case BalanceIncreaseGenesisBalance:
+		return "BalanceIncreaseGenesisBalance"
+	case BalanceIncreaseRewardTransactionFee:
+		return "BalanceIncreaseRewardTransactionFee"
+	case BalanceDecreaseGasBuy:
+		return "BalanceDecreaseGasBuy"
+	case BalanceIncreaseGasReturn:
+		return "BalanceIncreaseGasReturn"
+	case BalanceIncreaseDaoContract:
+		return "BalanceIncreaseDaoContract"
+	case BalanceDecreaseDaoAccount:
+		return "BalanceDecreaseDaoAccount"
+	case BalanceChangeTransfer:
+		return "BalanceChangeTransfer"
+	case BalanceChangeTouchAccount:
+		return "BalanceChangeTouchAccount"
+	case BalanceIncreaseSelfdestruct:
+		return "BalanceIncreaseSelfdestruct"
+	case BalanceDecreaseSelfdestruct:
+		return "BalanceDecreaseSelfdestruct"
+	case BalanceDecreaseSelfdestructBurn:
+		return "BalanceDecreaseSelfdestructBurn"
+	default:
+		return "unknown"
+	}
+}
+
 // GasChangeReason is used to indicate the reason for a gas change, useful
 // for tracing and reporting.
 //