params: add Rules2 (WIP)

Author: fjl

params/rules2.go

@@ -0,0 +1,38 @@
+// Copyright 2025 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package params
+
+import (
+	"github.com/ethereum/go-ethereum/params/forks"
+)
+
+// Rules captures the activations of forks at a particular block height.
+type Rules2 struct {
+	active map[forks.Fork]bool
+}
+
+func (cfg *Config2) Rules(blockNum uint64, blockTime uint64) Rules2 {
+	r := Rules2{
+		active: make(map[forks.Fork]bool, len(cfg.activation)),
+	}
+	return r
+}
+
+// Active reports whether the given fork is active.
+func (r *Rules2) Active(f forks.Fork) bool {
+	return r.active[f]
+}