Add missing methods to lambdaworks implementation

felt/Cargo.toml

@@ -19,7 +19,7 @@ lazy_static = { version = "1.4.0", default-features = false, features = [
     "spin_no_std",
 ] }
 serde = { version = "1.0", features = ["derive"], default-features = false }
-lambdaworks-math = { version = "0.1.1", default-features = false, optional=true }
+lambdaworks-math = { version = "0.1.1", default-features = false, optional = true }
 
 [dev-dependencies]
 proptest = "1.1.0"

felt/src/lib_bigint_felt.rs

@@ -142,11 +142,14 @@
     pub fn new<T: Into<Felt252>>(value: T) -> Self {
         value.into()
     }
+
+    #[deprecated]
     pub fn modpow(&self, exponent: &Felt252, modulus: &Felt252) -> Self {
         Self {
             value: self.value.modpow(&exponent.value, &modulus.value),
         }
     }
+
     pub fn iter_u64_digits(&self) -> U64Digits {
         self.value.iter_u64_digits()
     }
@@ -184,10 +187,13 @@
     }
 
     #[cfg(any(feature = "std", feature = "alloc"))]
+    #[deprecated]
     pub fn to_signed_bytes_le(&self) -> Vec<u8> {
+        // NOTE: this is unsigned
         self.value.to_signed_bytes_le()
     }
     #[cfg(any(feature = "std", feature = "alloc"))]
+    #[deprecated]
     pub fn to_bytes_be(&self) -> Vec<u8> {
         self.value.to_bytes_be()
     }

felt/src/lib_lambdaworks.rs

@@ -189,10 +189,31 @@ impl Felt252 {
         value.into()
     }
 
+    #[deprecated]
+    pub fn modpow(&self, exponent: &Felt252, modulus: &Felt252) -> Self {
+        Self::from(
+            self.to_biguint()
+                .modpow(&exponent.to_biguint(), &modulus.to_biguint()),
+        )
+    }
+
     pub fn iter_u64_digits(&self) -> impl Iterator<Item = u64> {
         self.value.representative().limbs.into_iter().rev()
     }
 
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[deprecated]
+    pub fn to_signed_bytes_le(&self) -> Vec<u8> {
+        // NOTE: this is unsigned
+        self.to_biguint().to_bytes_le()
+    }
+
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    #[deprecated]
+    pub fn to_bytes_be(&self) -> Vec<u8> {
+        self.to_be_bytes().to_vec()
+    }
+
     pub fn to_le_bytes(&self) -> [u8; 32] {
         // TODO: upstream should return array
         let mut bytes = [0; 32];