core/types: add SSZ encoders/decoders for BAL types from EIP 7928

core/types/bal.go

@@ -0,0 +1,55 @@
+package types
+
+//go:generate go run github.com/ferranbt/fastssz/sszgen --path . --objs PerTxAccess,SlotAccess,AccountAccess,BlockAccessList,BalanceDelta,BalanceChange,AccountBalanceDiff,CodeChange,AccountCodeDiff,AccountNonce,NonceDiffs --output bal_encoding.go
+
+type PerTxAccess struct {
+	TxIdx      uint64 `ssz-size:"2"`
+	ValueAfter [32]byte
+}
+
+type SlotAccess struct {
+	Slot     [32]byte      `ssz-size:"32"`
+	Accesses []PerTxAccess `ssz-max:"30000"`
+}
+
+type AccountAccess struct {
+	Address  [20]byte     `ssz-size:"32"`
+	Accesses []SlotAccess `ssz-max:"300000"`
+	code     []byte       `ssz-max:"24576"` // this is currently a union in the EIP spec, but unions aren't used anywhere in practice so I implement it as a list here.
+}
+
+type BalanceDelta [12]byte // {}-endian signed integer
+
+type BalanceChange struct {
+	TxIdx uint64 `ssz-size:"2"`
+	Delta BalanceDelta
+}
+
+type AccountBalanceDiff struct {
+	Address [40]byte
+	Changes []BalanceChange `ssz-max:"30000"`
+}
+
+// TODO: implement encoder/decoder manually on this, as we can't specify tags for a type declaration
+type BalanceDiffs = []AccountBalanceDiff
+
+type CodeChange struct {
+	TxIdx   uint64 `ssz-size:"2"`
+	NewCode []byte `ssz-max:"24576"`
+}
+
+type AccountCodeDiff struct {
+	Address [40]byte
+	Changes []CodeChange `ssz-max:"30000"`
+}
+
+// TODO: implement encoder/decoder manually on this, as we can't specify tags for a type declaration
+type CodeDiffs []AccountCodeDiff
+
+type AccountNonce struct {
+	Address    [40]byte
+	NonceAfter uint64
+}
+
+// TODO: implement encoder/decoder manually on this, as we can't specify tags for a type declaration
+type NonceDiffs []AccountNonce