feat: add balancer v2 executor

foundry/lib/balancer-labs/v2-interfaces/contracts/standalone-utils/IBalancerQueries.sol

@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program 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 General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+pragma solidity >=0.7.0 <0.9.0;
+pragma experimental ABIEncoderV2;
+
+import "../vault/IVault.sol";
+
+/**
+ * @dev Provides a way to perform queries on swaps, joins and exits, simulating these operations and returning the exact
+ * result they would have if called on the Vault given the current state. Note that the results will be affected by
+ * other transactions interacting with the Pools involved.
+ *
+ * All query functions can be called both on-chain and off-chain.
+ *
+ * If calling them from a contract, note that all query functions are not `view`. Despite this, these functions produce
+ * no net state change, and for all intents and purposes can be thought of as if they were indeed `view`. However,
+ * calling them via STATICCALL will fail.
+ *
+ * If calling them from an off-chain client, make sure to use eth_call: most clients default to eth_sendTransaction for
+ * non-view functions.
+ *
+ * In all cases, the `fromInternalBalance` and `toInternalBalance` fields are entirely ignored: we just use the same
+ * structs for simplicity.
+ */
+interface IBalancerQueries {
+    function querySwap(IVault.SingleSwap memory singleSwap, IVault.FundManagement memory funds)
+        external
+        returns (uint256);
+
+    function queryBatchSwap(
+        IVault.SwapKind kind,
+        IVault.BatchSwapStep[] memory swaps,
+        IAsset[] memory assets,
+        IVault.FundManagement memory funds
+    ) external returns (int256[] memory assetDeltas);
+
+    function queryJoin(
+        bytes32 poolId,
+        address sender,
+        address recipient,
+        IVault.JoinPoolRequest memory request
+    ) external returns (uint256 bptOut, uint256[] memory amountsIn);
+
+    function queryExit(
+        bytes32 poolId,
+        address sender,
+        address recipient,
+        IVault.ExitPoolRequest memory request
+    ) external returns (uint256 bptIn, uint256[] memory amountsOut);
+}