feat(decode): init calldata type guessing

common/src/constants.rs

@@ -14,6 +14,9 @@ lazy_static! {
     /// contract on Ethereum.
     pub static ref BYTECODE_REGEX: Regex = Regex::new(r"^(0x)?[0-9a-fA-F]{0,50000}$").unwrap();
 
+    /// The following regex is used to validate raw calldata
+    pub static ref CALLDATA_REGEX: Regex = Regex::new(r"^(0x)?[0-9a-fA-F]*$").unwrap();
+
     /// The following regex is used to reduce null byte prefixes
     pub static ref REDUCE_HEX_REGEX: Regex = Regex::new(r"^0x(00)*").unwrap();
 

common/src/ether/evm/core/memory.rs

@@ -5,6 +5,12 @@ pub struct Memory {
     // TODO: add bit-tracking for memory
 }
 
+impl Default for Memory {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl Memory {
     /// Creates a new [`Memory`] with an empty memory vector.
     pub fn new() -> Memory {

common/src/ether/evm/core/stack.rs

@@ -25,6 +25,12 @@ pub struct StackFrame {
     pub operation: WrappedOpcode,
 }
 
+impl Default for Stack {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl Stack {
     /// Creates a new [`Stack`].
     ///

common/src/ether/evm/core/storage.rs

@@ -10,6 +10,12 @@ pub struct Storage {
     access_set: HashSet<[u8; 32]>,
 }
 
+impl Default for Storage {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl Storage {
     /// Creates a new [`Storage`] struct.
     ///