✨ Calldata reader lib

src/collections/CalldataReader.sol

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.13;
+
+type CalldataReader is uint256;
+
+using CalldataReaderLib for CalldataReader global;
+
+/// @author philogy <https://github.com/philogy>
+library CalldataReaderLib {
+    function from(bytes calldata data) internal pure returns (CalldataReader reader) {
+        assembly {
+            reader := data.offset
+        }
+    }
+
+    function shifted(CalldataReader reader, uint256 n) internal pure returns (CalldataReader newReader) {
+        assembly {
+            newReader := add(reader, n)
+        }
+    }
+
+    function readBool(CalldataReader reader) internal pure returns (bool value) {
+        assembly {
+            value := byte(0, calldataload(reader))
+        }
+    }
+
+    function readU16(CalldataReader reader) internal pure returns (uint16 value) {
+        assembly {
+            value := shr(240, calldataload(reader))
+        }
+    }
+
+    function readU40(CalldataReader reader) internal pure returns (uint40 value) {
+        assembly {
+            value := shr(216, calldataload(reader))
+        }
+    }
+
+    function readU64(CalldataReader reader) internal pure returns (uint64 value) {
+        assembly {
+            value := shr(192, calldataload(reader))
+        }
+    }
+
+    function readU128(CalldataReader reader) internal pure returns (uint128 value) {
+        assembly {
+            value := shr(128, calldataload(reader))
+        }
+    }
+}